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table of contents Western Society of Trenchless Technology -

Trenchless review summer 2009 Chairman’s Message – Jennifer A. Glynn

6

NASTT Chairman’s Message – Chris Brahler

7

Trenchless Triumphs in Toronto – NASTT Executive Director Mike Willmets

8

WESTT Board of Directors

9

New CSM Shaft Construction Method Debuts in U.S. – Matthew Wallin & Mary Asperger, Bennett Trenchless

10

NASTT Calendar of Events

14

NASTT No-Dig Show Heads to Chicago in 2010 – Mark Hallett

17

Pilot Tube Microtunneling in Kaneohe, Oahu – Laura Anderson, Akkerman Inc.

19

Condition Assessment of Water Mains – Eugenia Chusid, Project Manager, City of Santa Monica

22

Calculate the Benefits of Going Trenchless – Michael Stimpson

24

Fifth Annual Western Regional No-Dig Conference & Exhibition

27

World’s Largest Pipe Renovation with FRP Completed Ahead of Schedule – Mo Eshani & Carlos Peña, QuakeWrap

29

2009 International No-Dig Show a Record-Breaking Success – Angela Ghosh, NASTT Asst. Executive Director

34

Rehabilitating Sewer Pipeline in Ecologically Sensitive Site – Russell Bergholz & Vipul Joshi, Dudek Engineering

36

Trenchless, To Go – Robbins SBU Makes 72-Hour Deadline for Urban Water Project – Desiree Willis

40

Sharing Technologies Together – Roberts McMullin, URS Corporation, PUG Secretary

45

Pipe Bursting in West L.A. Proves Advantageous – Keith Hanks, Richard Pedrozo, Mina Azaria, Art Khachikian, & Teresa Cajahuaringa

47

Manhole Rehabilitation in Singapore: going the extra several thousand miles in search of the right solution - Angus W. Stocking

50

Laser Profiling in Plastic Pipe – Ken Lucas, Geolyn Pipe Inspection Services Ltd.

52

Conflict Resolution: Unique Design Solves Complex Sewer Issue in Phoenix – Arvid Veidmark III, SSC

54

Large Diameter Slipling and CIPP Work Together in Albuquerque, NM – Michael Rocco, AUI Inc.

56

Trenchless First in Phoenix: Static Pipe Bursting Teams With NO-DIG VCP – Collins Orton, Robert Webb, & Jeff Boschert

58

Index to Advertisers

63

Published by:

Managing Partner and Editor Paddy O’Toole 204.255.6524 [email protected]

COMMUNICATIONS

Advertising Sales Andrew Pattison 204.275.6946 [email protected]

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While every effort has been made to ensure the accuracy of the information contained herein and the reliability of the sources, the Publisher in no way guarantees or warrants the information herein, and is not responsible for errors, omissions, or statements made by advertisers. Opinions or recommendations made by contributors or advertisers are not necessarily those of PTR Communications, its officers or employees. Printed in Canada 08/09

Western Society of Trenchless Technology - Trenchless Review - 2009

5

Chairman’s message Jennifer A. Glynn

Resort on September 10-11th, 2009 on Waikiki Beach in beautiful Honolulu, Hawaii.

Welcome to the newest edition of the Western Regional Trenchless Review! As our regional chapter continues to become established in the industry, we are excited to produce and distribute valuable information and ideas centered on a region of the country that continues to grow and thrive despite the difficult economy. Thank you to all the advertisers and article contributors for helping to make this year’s magazine a success. As my first full year as Chairman of WESTT draws to a close, I am proud to say that our regional chapter continues its work toward the advancement of the science and practice of Trenchless Technology for public benefit through promoting and conducting education and training. We had great success with last year’s Annual Western Regional Mini No-Dig Conference and Exhibition in Sacramento, California. This year, the Fifth Annual Conference will be held in Honolulu, Hawaii! The event will be held at the Sheraton Waikiki

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The Conference is being held in Hawaii this year as an effort to bring the benefits of the National No-Dig Conference to members of the engineering community in Hawaii who might not otherwise have had an opportunity to attend. The Chapter is also pleased to announce that, as part of the conference, we will be offering the option of two 8-hour NASTT Good Practices Design courses. This year’s focus is really about our goal to become a “local” source for connecting individuals interested in learning about various trenchless technologies as a viable solution to their infrastructure needs.

I look forward to another excellent year for trenchless activities in the Western region and welcome new members to join the Western Chapter. Please feel free to contact me at [email protected] or (925) 627-4151 or check out our website at www.westt.org if you require any information on WESTT or trenchless in general.

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Western Society of Trenchless Technology - Trenchless Review - 2009

Warmest regards,

Jennifer A. Glynn, P.E. Chairman, WESTT

NAsTT Chairman’s message Chris Brahler

hard work begins with NASTT Regional Chapters like the WESTT.

The first part of my term as NASTT Chair has been exciting and energizing! It has been an honor to represent an association and an industry that in so many ways epitomizes the true spirit of innovation, ingenuity and good old fashioned hard work. That

Your commitment and dedication is so important to the success of the trenchless industry as a whole that it cannot be overstated. You make it happen. Through educational programs, training events and, of course, the projects in the field, you advance the cause and elevate the industry.

Congratulations to WESTT for all of the great work being done. Also, best wishes for a successful 5th Annual WESTT No-Dig Show, September 10-11, 2009, at the Sheraton Waikiki Resort, Honolulu, HI. I hope to join you there! Chris Brahler Chairman, NASTT TT Technologies, Inc.

tŚĞŶ ŝ ƚ  ĐĂŵĞ ƟŵĞ ƚ Ž ŝ ŵƉƌ ŽǀĞ ŽƵƌ  tŚĞŶŝƚĐĂŵĞƟŵĞƚŽŝŵƉƌŽǀĞŽƵƌ ĐŽŵŵƵŶŝ ƚ LJ͕  ǁĞ ǁĞƌ Ğ ƚ ŚĞƌ Ğ͘ ĐŽŵŵƵŶŝƚLJ͕ǁĞǁĞƌĞƚŚĞƌĞ͘ Your Trusted Trenchless Technology Provider

For 40 Years We’ve Been There tŚĞŶ ŝ ƚ  ĐĂŵĞ ƟŵĞ ƚ Ž ĞdžƉĂŶĚ ŽƵƌ  tŚĞŶŝƚĐĂŵĞƟŵĞƚŽĞdžƉĂŶĚŽƵƌ Śŝ ŐŚǁĂLJƐ͕  ǁĞ ǁĞƌ Ğ ƚ ŚĞƌ Ğ͘ ŚŝŐŚǁĂLJƐ͕ǁĞǁĞƌĞƚŚĞƌĞ͘

tŚĞŶ tŚĞŶŝƚ ŝ ƚ ĐĂŵĞ ĐĂŵĞƟŵĞ ƟŵĞƚŽ ƚ ŽƌĞďƵŝůĚ ƌ ĞďƵŝ ů ĚŽƵƌ ŽƵƌ  ĞĐŽŶŽŵLJ͕ǁĞǁĞƌĞƚŚĞƌĞ͘ ĞĐŽŶŽŵLJ͕  ǁĞ ǁĞƌ Ğ ƚ ŚĞƌ Ğ͘

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7

Trenchless Triumphs in Toronto NAsTT executive Director Mike Willmets

If you’re committed to making smart decisions for underground infrastructure, it’s a pretty good bet that you attended the 2009 International No-Dig Show in Toronto, Canada from March 29th to April 3rd. Over 1,900 people from 43 countries certainly thought it was the right thing to do and it looks like the No-Dig Show really does the right thing by “helping you make smart decisions even smarter”! This was the first International No-Dig ever to be presented in Canada and NASTT’s third in conjunction with our co-hosts, the International Society for Trenchless Technology. To the credit of the 2009 Program Committee, 140 peer-reviewed technical papers were presented, the most ever for a No-Dig Show. Our industry exhibitors were in full force too, as the Sheraton Centre exhibit halls were completely sold-out representing 124 companies, many of whom were using this event to launch new trenchless products. Many thanks to our premium level sponsors and exhibitors for their welcomed support and generosi-

8

ty. For those with an appetite for trenchless training, all six of the NASTT Good Practices courses were presented for the first time under one roof and very well attended. Special thanks to our excellent volunteer instructors! Undoubtedly, the Toronto show was a milestone event for NASTT, not only because we broke all our attendance and sponsorship records, but because this occurred during a very challenging economic period. We have all developed a new attitude towards thriftiness and for the NASTT No-Dig Show to receive the Trenchless industry’s stamp of approval is perhaps recognition of top notch quality and the best value for your ticket price. Especially commendable was the record setting contributions at the 8th Annual Educational Fund Auction. Helping our students is the best investment we could ever make. Thank you for your generosity. Of course, it is volunteerism that drives NASTT and the No-Dig Show. Without the

enormous commitment of our membership, much of what is presented at our annual event would not be possible. The contribution of the WESTT Chapter deserves special recognition and praise as it does at every No-Dig Show. Collectively, WESTT is an impressive and inspirational group that have become a strong voice in our industry. Thank you for allowing your talents to be tapped and for your enthusiastic support. Best wishes and continued success to WESTT. Hope to see you in Chicago in 2010.

Mike Willmets Executive Director, NASTT

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Western Society of Trenchless Technology - Trenchless Review - 2009

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WesTT Board of Directors

WESTT Board of Directors: Jennifer Glynn, Chairman - RMC Water and Environment Matthew Wallin, Treasurer – Bennett Trenchless Engineers Jason Lueke, Secretary - Arizona State University Samuel Ariaratnam, Advisor –Arizona State University

Craig Camp, Director –Jacobs Associates James Ciesielski, Director –Las Vegas Valley Water District Collins Orton, Director –TT Technologies Cindy Preuss, Director –Harris and Associates Michael Rocco, Director –AUI Incorporated Paul Reilly, Director –Rain for Rent Mike Stram, Director –City of Reno Robert Webb, Director –Project Engineering Consultants Western Society of Trenchless Technology - Trenchless Review - 2009

9

New CSM Shaft Construction Method Debuts in the United States Matthew Wallin & Mary Asperger

INTRODUCTION In 2007, the East Bay Municipal Utility District began construction of its Folsom South Canal Connection Project. The 19-mile pipeline was installed primarily using open-cut construction; however, a microtunneled crossing of the Mokelumne River was required. It was for this crossing that the cutter soil mixing (CSM) construction method was used for the first time in the United States to construct access shafts for a microtunneled drive. SITE CONDITIONS The site soil conditions consisted of approximately 35 feet of stiff clay and very dense sand with gravel overlying soft rock. The rock primarily consisted of soft sandstone with strengths of 300 to 1,000 psi with some interbeds of siltstone, claystone, and agglomerate up to 2,000 psi. Of particular concern was the possible presence of cobbles or boulders that might present possible obstructions or complicate shaft construction. Groundwater recharge from the river through the permeable sands and gravels

10

meant that attempts to dewater the ground outside the shafts would be very difficult, if possible at all. DESIGN CONSIDERATIONS The shaft construction method needed to provide a safe, dry, excavation large enough for both the microtunneling equipment and the sweeping 90-degree bends in the final pipeline. The shafts would have to be installed through potentially flowing sands, some cobbles and boulders, and competent soft rock. Additionally, the shafts had to provide not only watertight walls, but also a sealed base that could resist the buoyant uplift loads when the shaft was complete and dry.

considered during design included interlocking steel sheetpiles, auger drilled shafts, sunken concrete caissons, and secant piles. Steel sheetpiles were eliminated from consideration early because of concerns about the ability to successfully drive the sheets through the anticipated cobbles, boulders, and rock. There was also concern about the produc-

The watertight shaft methods

Western Society of Trenchless Technology - Trenchless Review - 2009

UPCOMING EVENTS tion rates for advancing a sunken caisson in the difficult soils. Finally, the necessary shaft diameters were at the edge of what was feasible for auger-drilled shafts. These concerns left secant pile shafts as the most likely shaft construction method. However, traditional secant pile construction would also have been challenging, with slow drilling likely in the difficult ground. CUTTER SOIL MIXED (CSM) METHOD In May 2007, Sundt, Inc. was named the general contractor for the open-cut portion, with Drill Tech Drilling and Shoring, Inc. (Antioch, CA) as the shaft subcontractor. As an alternative to the methods in the specifications, Drill Tech submitted a proposal to use cutter soil mixing (CSM) as the shaft construction method. This process was new to the Owner and the Engineers;

however, CSM is similar in principle to the accepted secant pile method. Unlike traditional secant pile construction where the native soil is replaced with concrete columns, CSM forms rectangular walls by mixing the native soil in place with bentonite and cement to form soilcrete panels. The overlapping panels are then formed into a shaft, in whatever pattern is needed for the particular project. The primary difference between CSM and more traditional soil mixing lies in the equipment used to create the soilcrete panels. Instead of a single- or tripleaxis auger drill rig where the augers turn around a vertical axis, the mixing tools of a CSM machine rotate around a horizontal axis. Two counter-rotating cutterwheels are mounted on a continuous drill stem that can control their position in all three dimensions. An advantage to this configuration is that the cutter gear

Contractor’s design for the CSM shafts, including breakout area

drives are located on the end of the drill stem and advance with the drilling head. This configuration allows for inclinometers to be used to provide real-time tracking of the cutter’s position during drilling, allowing for more accurate panel construction. The data collected regarding cutter head location, as well as cutterwheel RPM, down pressure, penetration rate and fluid injection rates and pressures are monitored and tracked on a control screen in the operator’s cabin. There are a variety of mixing tools available for different soils. The end product is a rectangular panel of soilcrete, as opposed to the cylindrical column created by a traditional auger. Panels can be created using either a single- or two-step process. In the two-step process, as was used on this project, the ground is fluidized by injecting bentonite slurry as the cutter wheels progress downward. When the final depth is reached, the cutter wheels are raised as cement slurry is mixed with the

Close-up view of CSM cutterwheels

Western Society of Trenchless Technology - Trenchless Review - 2009

11

bentonite and soil cuttings. The single-step process combines the two steps and is suitable for applications in softer ground where progress will be quick, reducing the risk of the soilcrete setting while the rig is still drilling. When multiple panels are to be drilled, CSM uses an alternating method of primary and secondary drilling as is common for secant piles. The primary panels are drilled consisting of every other panel. After the primary panels have cured, secondary panels are drilled, overlapping between the primary panels. The CSM method has been used in Europe and Asia to form retaining walls, cut-off walls, foundations, levee reinforcement, and excavation supports. However, this project was not only the first use of CSM in the United States, but was also the first time that a Bauer CSM rig was used to create access shafts for a microtunneling drive. (Mainer, 2008) SHAFT CONSTRUCTION

Shaft excavation

12

Drill Tech’s proposed design for the Mokelumne River shafts used twelve panels, 94 inches in length and 30 inches wide, overlapping to approximate a circular shaft with a finished inside diameter of 24 feet. The final excavated depths of the shafts were 51 feet and 38 feet below grade. To provide groundwater cutoff, the panels were designed to extend to 70 feet and 51 feet below grade. An additional level of conservatism was included by the contractor. While the soilcrete panels were still wet, a wide flange beam was embedded in each panel. Additionally, several levels of ring steel were then installed during excavation. A unique feature of the design was the breakout areas. At both shafts where the MTBM would come through the shaft wall, the contractor constructed a sealed rectangular chamber by drilling four additional overlapping panels. These panels created a small, isolated zone, which could be

dewatered, eliminating the need for ground improvement outside the shafts. Drilling proceeded relatively smoothly at both shafts. Drilling of the 16 panels for the jacking shaft took 13 total days, averaging approximately 85 feet of drilling per day. The shallower reception shaft took only 11 days, however the drilling average was only 75 feet per day due to cobbles near the surface and the higher percentage of rock. Volumetrically, approximately 60 yd3 of material could be treated in one day, including panel setup, beam placement, and QC testing. Once the soilcrete panels had cured, excavation began in each shaft. Excavation was accomplished using a hydraulic excavator for the upper 20 to 25 feet. Once the work extended beyond the reach of the hydraulic excavator, the remainder of the excavation proceeded using a miniexcavator, crane, and muck buck-

Drilling the primary panels at the jacking shaft

Western Society of Trenchless Technology - Trenchless Review - 2009

Placing the wide flange steel beam in a soilcrete panel ets. The ring steel was installed as excavation progressed and seal slabs were placed at the bottom.

shaft volume the cost was approximately $900 per cubic yard. For the West Coast, this cost places these CSM shafts within the order of magnitude typically seen for secant piles or more complex auger drilled shafts, but below the typical cost of sunken concrete caissons. While this cost is significantly higher than typical sheetpile shafts, it should be noted that the ground conditions at this location would have made sheetpile construction much more costly, if even possible. CONCLUSION

The FSCC Mokelumne River crossing was ultimately a very successful trenchless project thanks to all involved parties. Drill Tech’s use of the innovative CSM-method of shaft construc-

CONSTRUCTION COST The bid for the shafts was $1.4M or approximately $15,000 per foot of depth. Calculated by

The completed shaft

tion provided a safe, dry, excavation in very challenging ground. Further, the CSM method has many applications beyond shaft construction including larger excavation support, foundation construction, levee and dam improvement, and curtain walls. Several additional CSM projects have already been completed by this and other west coast contractors. We expect to see CSM used on many projects in the future, trenchless and otherwise. REFERENCE Mainer, B., and Gerressen, F. (2008). First Use in the USA of the CSM Method for use as Microtunnel Sending and Receiving Shafts. Proceedings of 2008 Deep Foundations Institute Annual Conference on Deep Foundations, New York, New York, October 15-17, 2008. Matthew Wallin is a Senior Project Engineer at Bennett Trenchless with over 9 years of experience in Trenchless Technology. Mary Asperger is an Associate Engineer at Bennett Trenchless.

Looking up out of the completed shaft

Western Society of Trenchless Technology - Trenchless Review - 2009

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calendar of events NAsTT Training Courses, Conferences & Chapter events Trenchless Technology, SSES and Buried Asset Management Seminar

NASTT New Installation Methods Good Practices Course

Tuesday, August 11, 2009 - Wednesday, August 12, 2009 Radisson Quad City Plaza Hotel (Downtown) - Davenport, Iowa Sponsored by the Midwest Society for Trenchless Technology. Seminar offers presentations on trenchless technologies and an exhibit trade show. Contact Info: Web site: http://www.mstt.org Leonard Ingram Phone: 888-817-3788 Email: [email protected]

Tuesday, November 24, 2009 Calgary, Alberta Sponsored in conjunction with the 2009 NASTT Northwest Trenchless Conference. Course instructors are Glenn Boyce and Craig Camp. Topics covered: auger boring, pipe ramming, pipe jacking, and the pilot tube methods. Contact Info: Web site: http://www.nastt-nw.com Angela Ghosh Phone: 703-217-1382 Email: [email protected]

5th Annual Western Regional No-Dig Conference & Exhibition Thursday, September 10, 2009 - Friday, September 11, 2009 Sheraton Waikiki Resort - Honolulu, Hawaii Day 1: Technical Paper Presentations; Day 2: Choose to attend the HDD Good Practices Guidelines or NASTT Pipe Bursting Good Practices Courses. Both days included in the full conference registration fee: $300 before 8/10/09 and $350 after. Discounts for agencies. Contact Info: Web site: www.nastt.org/westt Matthew Wallin Phone: 916-294-0095 Email: [email protected]

NASTT Pipe Bursting Good Practices Course Friday, September 11, 2009 Sheraton Waikiki Resort - Honolulu, Hawaii Types, methods and applications of pipe bursting; planning and preliminary design; design and construction; and troubleshooting. Registration to this course is included with full conference fee to attend the 5th Annual Western Regional No-Dig Conference & Exhibition. $300 before 8/10/09 and $350 after. Contact Info: Web site: www.nastt.org/westt Matthew Wallin Phone: 916-294-0095 Email: [email protected]

HDD Good Practices Guidelines Course

2009 NASTT Northwest Trenchless Conference Wednesday, November 25, 2009 Calgary, Alberta The Northwest Chapter of the North American Society for Trenchless Technology is hosting the 2009 NASTT Northwest Trenchless Conference in Calgary on November 24 and 25, 2009. This conference includes a one day short course and one day of technical presentations focused on all aspects of trenchless construction. The Northwest Chapter Project of the Year will be also awarded at the conference. Please visit the web site at www.nastt-nw.com for abstract and Project of the Year submission requirements. Contact Info: Web site: http://www.nastt-nw.com Duane Strayer Email: [email protected]

2010 NASTT No-Dig Show Sunday, May 2, 2010 - Friday, May 7, 2010 Renaissance Schaumburg Hotel - Chicago (Renaissance), Illinois Sponsored by the North American Society for Trenchless Technology (NASTT). Contact Info: Web site: http://www.nodigshow.com Benjamin Media, Inc. (Conference Management) Phone: 330-467-7588 Email: [email protected]

Friday, September 11, 2009 Sheraton Waikiki Resort - Honolulu, Hawaii In-depth overview of HDD from planning to job completion. Registration to this course is included with full conference fee to attend the 5th Annual Western Regional NoDig Conference & Exhibition. $300 before 8/10/09 and $350 after. Contact Info: Web site: www.nastt.org/westt Matthew Wallin Phone: 916-294-0095 Email: [email protected]

14

Western Society of Trenchless Technology - Trenchless Review - 2009

Veolia Environmental Services (Veolia ES) Industrial Services acquired JF Pacific Liners in 2008. Pacific Liners will soon be known as Veolia ES Sewer Services. Veolia ES Sewer Services offers trenchless services to evaluate, maintain and rehabilitate municipal and industrial sewers and storm drains and their associated structures.

Available Services and Products: Inspection Mini Cameras Self Propelled Cameras Water and Dye Testing Color Cameras

Smoke Testing Rainfall Simulation Pan and Tilt Viewing Air and Vacuum Testing

Cleaning Hydro Cleaning Mechanical Bucketing Root Cutting/Treatment Jet/Vac Combo

Mechanical Rodding Obstruction Removal Pigging and Balling Water Blasting

Rehabilitation Pipe Bursting Sewer Pipe Crown Spraying Fold & Form PVC Pipe Lining Spot/Point Repair

Lateral Lining Cementitious Pipe Coating Manhole Rehabilitation Cure-In-Place Pipe Lining (CIPP)

Extra Services Flow Monitoring Corrosion Detection Deflection Testing Grade Profiling Re-Rounding

Sonar Spinning Laser Pipe Geometry Location & Quantity of Underwater Sediment

Please contact us for further assistance: Veolia ES Sewer Services, Inc. 70 Union Way Vacaville CA 95687 Tel: 707 446 8222 - Fax: 707 447 3661 www.VeoliaES.com

Turning waste into a resource

QUESTIONS ABOUT TRENCHLESS?

We Have Answers. NORTH AMERICAN SOCIETY FOR

TRENCHLESS TECHNOLOGY TM

Get Connected to the Trenchless Industry

Join Today

NASTT is your link to thousands of local, national and international trenchless professionals and industry leaders. Whether your business is engineering, public works and utilities, underground construction, or equipment manufacturing, NASTT is the definitive resource for the trenchless industry and the application of trenchless methods for the public benefit.

From educational resources to training tools and more, NASTT members have access to a wealth of valuable information and networking opportunities.

Education & Training NASTT provides top-notch, quality education and training programs for trenchless professionals. Currently, NASTT offers six training courses covering Cured-in-Place-Pipe (CIPP), Horizontal Directional Drilling (HDD), pipe bursting, sewer lateral rehabilitation, an overview of trenchless technologies, and new installation methods such as auger boring, pipe jacking, pipe ramming, and the pilot tube method. Earn Continuing Education Units (CEUs) for your participation.

Membership benefits include: • Members-only discounts • Complimentary access to online reference tools and publications • Subscriptions to industry trade magazines • Leadership opportunities • Involvement in your regional chapter • And much more! Our members often join for one reason, only to discover the value of many others. Joining is easy. Visit our Web site at www.nastt.org or call 613-424-3036 (in Canada) or 703-217-1382 (in U.S.) for membership details.

The Show! The annual No-Dig Show is the largest trenchless technology event in North TM America, offering an impressive collection of quality papers, an exhibition hall with more than 125 trenchless companies displaying their products and services, a series of specialized training courses, and many entertaining networking events and special awards. Mark your calendars for NASTT’s No-Dig Show, May 2-7, 2010, in Chicago (Schaumburg), Illinois!

1655 N. Ft. Meyer Drive, Suite 700 Arlington, VA 22209 Phone: 613-424-3036 (in Canada) or 703-217-1382 (in U.S.)

NASTT’s No-Dig Show Heads to Chicago in 2010 Mark Hallett

Dear Trenchless Colleagues, On behalf of NASTT and the No-Dig Program Committee, I am pleased to announce that Chicago has been chosen as the destination location for the 2010 No-Dig Show, May 2-7. 2010 is a very special year for NASTT as we will be celebrating our 20th anniversary. In 1990, five key people began to brainstorm on the possibility of establishing a new association just for trenchless technology. That organization became known as NASTT and those five people became its founding members. Twenty years later, our society is a vibrant, growing organization of more than 1,200 members in the U.S., Canada and Mexico.

It is very appropriate that we return to the birthplace where NASTT began – in Chicago – to celebrate this significant milestone. To showcase the 20-year history of NASTT, we have planned a multi-media exhibit including interviews of past chairs, photographs and video, among other special events and awards. (I’ll have more information to report in my next letter.)

Trenchless Equipment, Materials and Methods

The conference theme of Rebuilding North America’s Underground Infrastructure using Trenchless Technology will prove to be timely and relevant given that throughout North America there is a renewed focus of investing in our infrastructure.

Chicago’s central location and dense population make it an ideal place to do business. After hours, world-class dining, theater and attractions await you! As you can see, Chicago has a lot to offer our No-Dig attendees.

New topics for 2010: Infrastructure Investment; Environmental Issues; Social Costs and Impacts; Industry Trends, Issues and Concerns; Cutting-edge Advancements; and New Concepts for

No-Dig 2010 will be held at the Renaissance Schaumburg Hotel and Convention Center – a beautiful, luxurious new facility that combines hotel and meeting space – all in one location. The host hotel and event venue is convenient and accessible – 12 miles from O’Hare Airport and 26 miles from downtown Chicago.

Please consider joining us next year at No-Dig 2010 as we learn how to Rebuild North America’s Underground Infrastructure Using Trenchless Technology. For conference updates and information, be sure to visit our web site at www.nodigshow.com. Regards,

Mark Hallett

Western Society of Trenchless Technology - Trenchless Review - 2009

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Pilot Tube Microtunneling Delivers Pinpoint Accuracy in Kaneohe, Oahu Laura Anderson Marketing Specialist Akkerman Inc. Trenchless methods are a necessity when performing Hawaiian sewer upgrades where modest amounts of soil and sandy, soft ground conditions are vastly prevalent. Often, groundwater is encountered just slightly below the surface. The $8M Kaneohe Bay Trunk Sewer Reconstruction project, located on the island of Oahu, was designed to anticipate excess groundwater and yet construct a perfectly graded gravity sewer for the 35,000+ residents of Kaneohe. The project is owned by the City and County of Honolulu, and engineered by Funkunaga & Associates. Upon its anticipated completion in May of 2010, a total of 848 linear feet of 18 inch OD NO-DIG clay pipe will be installed. Contractor Frank Coluccio Construction of Kapolei, HI is performing the work The 848 liner feet of new sewer line is located near residential Kaimalu Place road, just off of Kaneohe Bay Drive. A small loop of homes featuring mature mango trees, encompassed by a canal creates a scenario for the importance of minimal construction disruption for these residents. The job, commenced in January 2009, consists of ten shafts at 13-15 linear feet in

Mature mango tree that would have been destroyed if open cut methods were applied on this job. depth, and ten drives ranging from 51-159 feet. Groundwater was encountered at just 4 feet. Jet grout supports, or columns were created and injected all along the lengths of the pipe string to provide ground stabilization. Following the installation of the grout supports, crew from Frank Coluccio Construction used an Akkerman Guided Boring Machine 308A and a Powered Cutter Head (PCH) 22.5” to install the NO-DIG clay pipe. The guided boring method, also known as pilot tube microtunneling (PTMT) has become increasingly popular as an alternative to traditional microtunneling. It

allows the contractor to install small diameter pipes (up to 48” OD) in a myriad of ground conditions in a minimal diameter shaft (8 feet) with pinpoint accuracy. The use of an LED target was viewed down the center of the pilot tubes with a theodolite and LCD. PTMT performs well in most displaceable soil conditions. The powered cutter head operates within the typical PTMT three-pass process. First, pilot tubes are installed on line and grade with the jacking frame and a guidance system. Second, the bore diameter is increased by installing the temporary augers and casings. The third step is to

Western Society of Trenchless Technology - Trenchless Review - 2009

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install the powered cutter head behind the augers and casings. The augers are then reversed by the PCH’s hydraulic drive and push spoils to the reception shaft while cutting the tunnel to the final pipe diameter. The final product pipe is installed behind the PCH. As each section of augers and casings is removed from the reception shaft, a section of product pipe is installed in the launch shaft until the total drive length is complete. At the time this article was submitted, four drives were completed successfully, including the longest drive. They anticipate completion in early Fall of this year. Frank Coluccio Construction has been involved in several other projects for the City and County of Honolulu. The Kapiolani Boulevard Water

Frank Coluccio Construction operators install an 18” OD section of NO-DIG clay pipe using their Akkerman 308A Guided Boring Machine and Powered Cutter Head 22.5” systems.

Service, Reliability and Innovation.

Since 1973, Akkerman Inc. has manufactured distinctive microtunneling, pipejacking, tunneling, guided boring and earth pressure balance equipment for tunnels up to 14’ in diameter. We attribute Akkerman Inc.’s reputation for superior reliability and responsive service to our team of experienced engineers, field technicians and our extensive parts department. Earth Pressure Balance | Guided Boring | Microtunneling | Pipejacking 58256 266th Street | Brownsdale, MN 55918 | USA 800.533.0386 | 507.567.2261 | fx. 507.567.2605 w w w.akkerman.com | e -mail: [email protected]

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Western Society of Trenchless Technology - Trenchless Review - 2009

and Sewer Improvement project was completed last year, where 600 linear feet of 24” OD pipe was installed. Crews are also currently working on the Wanaao Road and Keolu Drive Sewer Reconstruction where Frank Coluccio crews are installing a total of 2,890 linear feet of pipe ranging in size from 8-24” OD. Currently, 120 wastewater treatment projects are underway in Oahu.

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Crew members remove casing and augers sections from the reception shaft.

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Western Society of Trenchless Technology - Trenchless Review - 2009 7/14/09

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9:25 AM

Condition Assessment of Water Mains Eugenia Chusid Project Manager, City of Santa Monica, CA In January of 2009, the ASCE published a report card for our aging infrastructure. Per this report, “America’s drinking water system face an annual shortfall of at least $11 billion to repair/replace aging facilities that are near the end of their useful lives and to comply with existing and future federal water regulations. This does not account for growth in the demand for drinking water over the next 20 years. Leaking pipes lose an estimated 7 billion gallon of clean drinking water a day.” To repair our increasingly aging water system we will need significant investments and a Condition Assessment of the existing system will become a very important tool in helping to establish and record the state of the critical aspects of an existing infrastructure. Most water distribution networks in USA comprise of: 70% to 80% of Cast Iron (CI) and Ductile Iron (DI) pipes, 14% to 16% of Asbestos-Cement (AC) pipe, and the remaining pipes are plastic pipes – Polyvinyl Chloride (PVC) or High-density Polyethylene (HDPE). The final Condition Assessment Report should identify options for future actions to prevent failure, establish records against which future changes can be judged, and will help agencies with budgeting for repair /replacement programs. The benefits of having an assessment and renewal program in place will help with: • Planning and managing economically repairs/replacement to the existing system. • Will improve water quality. • Will provide customer satisfaction, and • Will improve fire flow and hydraulics. In the AC pipes aggressive water can cause fiber release, weakening the pipe and raising health concerns. It could also be softened by external corrosion which could weaken the pipe. For CIP and DIP, critical aspects are wall thickness and degree of corrosion. In the last 20 years plastic pipes industry had matured and improved, however it has its own capabilities and limitations. The first step in the assessment process of the existing water system is capacity analysis. The results will govern other considerations. If the capacity

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analysis show that the existing pipe is undersized then the only questions should be when, how, what size and with what material the new pipe be constructed. The second step is to perform risk assessment of the system and its components. Using leak history, pipe size/flow, pressure, age, soil corrosiveness, and material type each pipe segment is given a score in each category. The score summary will yield a relative ranking of all pipes in the system. The immediate attention should be paid to the pipes with the highest ranking. However, this method of ranking will also give you a list of pipes that are considered non-critical, and will not need attention for some time. The third step is to perform economic analyses – repair vs. replacement. Additional testing could be expensive and not always necessary. For the small size pipes, a majority of the agencies use an extrapolated corrosion future rate to develop an economically based replacement plan. It makes sense to replace existing pipe when cost of repair/ maintenance equals and/or exceeds the cost of a new replacement. The forth step is use of additional tools and techniques that could provide the information on a condition of the specific pipe segment of the existing system. The results could be used to determine longevity of the existing system, help to forecast future renewal needs and financial planning. Traditionally, decisions to replace or rehab existing pipe have been based on maintenance reports, failure history, flow testing, type, size and age of the pipe, and visual inspection. However, the optimal decision requires reliable information about the overall condition of the pipe line. This type of information could be attained by: 1.Non-Destructive/Disruptive method of inspection – using special equipment and techniques to inspect pipe within without digging and/or cutting existing pipe. 2.Controlled Destructive Examination – pressure testing of old pipes in search of structural weaknesses. Then problems are identified, and detailed investigation is in order. The removed bad section of the pipe will provide valuable information about the condition and expected life of the rest of the pipeline. 3.Destructive method of inspection – digging up existing pipe for visual inspection and in some

Western Society of Trenchless Technology - Trenchless Review - 2009

cases, cutting samples for the laboratory analysis. This method is not likely to reveal much and could be misleading. Corrosion processes in pipes are not uniform, and equipment can damage the pipe, and/or its coating. In addition it will introduce oxygen into the bedding materials, accelerating the corrosion process. The water main pipe Condition Assessment is not as easy as for the wastewater system. The Video Inspection (CCTV) of the existing water pipe requires a lot of prep work: the segment of the water pipe under review will have to be removed from service and a by-pass will be required; the pipe will have to be cleaned from all tuberculation; all equipment used will need to be disinfected and allocated strictly for water pipe inspection. The post inspection chlorination and bacteria testing will follow after the inspection is done and prior to putting the water main back into service. Up until recently many utility companies relied on failure history to determine replacement /repairs requirements. However, new developments and improvements of the old equipment and techniques in Non-Destructive Testing (NDT) technologies (acoustic emission, acoustic leak detection, RFEC/TC, magnetic flux leakage, ultrasonic pulse velocity, ultrasonic guided lamb waves, and other) are here, lowering the cost, and providing reliable

information without disruption to service makes use of NDT more attractive. NDT provides direct indication of the structural condition of pipes and can pinpoint leak locations, specifically for: • Metallic pipes - loss of wall thickness due to internal and/or external corrosion; • AC pipes - weakening of the wall as a result of leaching out of the cement by aggressive waters; • PCCP pipes - lose strength as a result of the weakening of the concrete and corrosion-failure of prestressing steel. • Plastic pipes - lose strength as a result of chemical attack. Ten years ago the only solution to the problems with the old pipes was to dig the pipe up and fix the leak or replace the pipe line. Today agencies have multiple choices on how to deal with the elderly pipe system. Condition Assessment of the existing system helps to: • optimize operation and maintenance budgets by prioritizing pipeline maintenance expenditures; • accurately forecast capital improvement budgets by developing proactive preventative replacement plans; • determine the present value of the infrastructure; • extend the safe and economic operation of the pipelines by developing informed risk management strategies.

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Calculate the Benefits of Going Trenchless Michael Stimpson

renchless methods of installing underground pipe and cable have certain notinconsiderable advantages over conventional methods. The makers of equipment used in trenchless construction and rehabilitation have known this for a long time, as have the construction professionals who use that equipment and implement trenchless techniques.

T

The conventional approach of installing underground pipe by digging a trench, placing the pipe and then burying it means significant amounts of land must be disturbed and, at least in busy urban areas, everyday vehicle traffic is inconvenienced. In a large project, those disturbances and disruptions can be quite considerable. The trenchless alternative, on the other hand, requires less excavation for putting pipe and cable underground. That means less disturbance of the ground, reducing environmental impact. Trenchless construction also generally means less obstruction and muddling of vehicle traffic and other activities on or near the work site. And, of course, trenchless proponents say it’s the way to go in situations where excavation isn’t practical or the project is in an environmentally sensitive area.

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It also makes good sense because of reduced dust, pollution and noise, among other things. Clearly, the construction industry’s trenchless contractors have a strong case for their services. One “new” rhetorical instrument at their disposal relates to the recent rise in concerns over projects’ “carbon footprint,” pollution that scientists say contributes to global warming. Carbon footprint is the total amount of greenhouse gases produced by a project. It’s usually expressed in terms of the equivalent mass of carbon dioxide. In short, the question is how much is emitted in carbon-containing greenhouse gases during all of the tasks performed in a project. Carbon footprint and global warming have zoomed up the list of public issues in this decade, with virtually every major jurisdiction creating policies to reduce emissions. Cap-and-trade systems are on the horizon for U.S. and Canadian businesses, for example. And British Columbia’s provincial government has mandated all its cities to be “carbon-neutral” by 2012 – i.e., to find ways to offset their carbon emissions so that the net effect on he atmosphere is neutral. The North American Society for Trenchless Technology’s B.C. chapter (NASTT-BC) contends that going trenchless means lower carbon emissions than what is generated by typical open-cut procedures. David O’Sullivan, past chair and current board member of NASTT-BC as well as president of Surreybased P.W. Trenchless Construction since 2000, says the use of trenchless methods for a pipe replacement project can cut the carbon by an enormous percentage compared to use of the cut-and-cover option. The difference could be as much as 90 per cent, according to the construction industry veteran.

Western Society of Trenchless Technology - Trenchless Review - 2009

One important factor that makes trenchless more climate-friendly is in the huge amounts of fuel that must be burned to remove and replace material in the course of a conventional cut-and-cover project. That more conventional approach involves removing earth covering the utility zone, then moving and disposing of it, then replacing it and restoring it to solid ground. It’s easy to see how that requires a lot of energy generated by burning fossil fuels. As well, a study by University of Waterloo engineers showed how traffic disruptions during utility construction along roads result in excessive emissions from motor vehicles. The engineers concluded that trenchless construction eliminates much of that problem by reducing the disruption of traffic flows. “Reducing the amount of open trench also reduces the amount of soil removal to dump sites and importing fill material to fill the trench, minimizing truck emissions,” O’Sullivan recently told a construction magazine. NASTT-BC’s website (www.nastt-bc.org) offers a handy tool for figuring out how much less in carbon emissions a project could have if it were to be done via trenchless technology instead of open-cut methods. The Carbon Calculator, as it’s called, is the first online tool of its kind for trenchless-versus-excavation comparisons.

obtaining government funding for low-carbon-emission projects. To give the calculator a test drive, Underground Construction magazine entered data for the hypothetical installation of 1,000 feet of 12-inch pipe underneath asphalt. The Carbon Calculator said open-cut installation would release more than 700 tonnes of CO2 while the CO2 emissions in installation via slipline/pipebursting techniques would emit about one-tenth as much. It should be noted that there are numerous variables involved in calculating carbon emissions from a future or hypothetical project. The Carbon Calculator produces estimates based on the data entered by the user, not spot-on projections. Having said that, it does demonstrate how going trenchless can be much greener than installation in a large long whole in the ground. Regardless of what you think of global warming science, it is important that the construction industry care about its environmental impact, efficiency and public image.

“So, even if you do not buy into the reduced carbon concept, and think it is a government conspiracy, I think we all agree that we need to reduce our energy use,” P.W. Trenchless Construction President O’Sullivan wrote recently in David O’Sullivan Trenchless International magazine. “If we can use a number of methods of conIn a nutshell, here’s how the Carbon Calculator struction that can achieve these kinds of energy works: You enter basic project information and reductions and yet maintain our standard of living answer questions about pertinent project details; it then we need to change.” estimates the size of the project’s carbon footprint in O’Sullivan’s company, P.W. Trenchless terms of tonnes of carbon dioxide (CO2) emitted. It Construction, is a leading trenchless contractor in will estimate carbon emissions that would occur in B.C. that offers services in sliplining, pipebursting three types of trenchless construction: horizontal and directional drilling as alternatives to cut-anddirectional drilling, sliplining/pipebursting and, lastcover construction. Its personnel have been involved ly, cured-in-place pipe lining, point repair and groutin trenchless construction since many years before ing. The application’s output also includes an estiP.W. was founded in 2000. mate of how much trenchless techniques could O’Sullivan says he hopes to see trenchless conreduce carbon emissions. struction become “the default method of underThe Carbon Calculator was developed for NASTTground construction – not (just) an option to considBC by an engineering student at the University of er when site conditions make excavation difficult.” British Columbia and was made available online in The Carbon Calculator can help advance that cause. January 2008. Its uses since then have included the production of supporting data for proposals aimed at Western Society of Trenchless Technology - Trenchless Review - 2009

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Western Society of Trenchless Technology - Trenchless Review - 2009

WORLD’S LARGEST PROJECT ON PIPE RENOVATION WITH FRP COMPLETED AHEAD OF SCHEDULE Mo Ehsani, Ph.D., P.E., S.E. & Carlos Peña, M.S., P.E. INTRODUCTION The use of FRP structural linings to strengthen and/or rehabilitate existing pipelines is increasingly gaining widespread acceptance among power plant and utility facility managers. The versatility of the linings to conform to a wide range of diameters and lengths, their high strength properties, light weight, impermeability, thinness and fast rate of application/installation are some of the reasons why managers prefer FRP linings to other retrofit alternatives. FRP linings typically consist of fabrics made with high strength fibers that are soaked in an adhesive resin, and are applied like wall paper to the interior or exterior of the pipe surface. Once the resin cures, the fabric turns into a very thin (about 0.05”) composite laminate. The density and orientation of the high-strength fibers, as well as the fiber type (usually comprised of bundles of very small diameter strands of materials such as glass, carbon, or Aramid) are parameters that the engineer can vary in order to create customized FRP linings that meet specific project criteria. A recent innovation in FRP lining technology is the PipeMedicTM product, which is a very thin plant-manufactured laminate that adheres to the pipe surface

using only an epoxy paste. The greatest advantage of PipeMedicTM is that it eliminates the need for in-situ saturation of the fabric, thereby significantly increasing the speed and quality of the installation. When applied to the inner surface of a pipeline, the FRP lining becomes a trenchless alternative; all labor, equipment and materials are introduced into the pipeline through service access points, thus avoiding the need for excavation. Since many major pipelines lie under freeways and urban or industrial developments, excavation is not possible without major disruptions to traffic, production, or other normal operations. The economic impact of the disruptions, coupled with the significant investment required to replace deteriorated pipelines, increase the relevance of trenchless retrofit options. Although the use of FRP linings has focused on the rehabilitation of deteriorated pipelines that have been in service for decades, they can also be used to correct design and/or construction errors of new pipelines. Such was the case of the low-pressure pipeline at the “El Encanto” power plant outside San José, Costa Rica. This project included the installation of about 150,000 ft2 of FRP lining, and is the largest reported

FRP pipeline retrofit project to date. The design problems, and the FRP lining solution implemented to address them, are discussed herein. PROBLEM DESCRIPTION The low-pressure pipeline at the “El Encanto” power plant (see Figure 1) conveys river water from an upstream dam to the turbine complex downstream. The pipeline is built of cast in place reinforced concrete, has an inner diameter of 7 ft, and a total length of 5,742 ft. The water flows by gravity, but because of the elevation difference between the dam and turbine complex, as well as the continuous changes in the vertical alignment of the pipeline required to conform to the mountainous topography, the water flow is pressurized.

(Insert photo 1 here)

Figure 1: Above ground segment of the “El Encanto” pipeline Although the structural design properly addressed the strength

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requirements of the pipeline and accounts for the design pressure and hydrodynamic loads, the pipeline’s serviceability requirements were overlooked in the structural design. The pipeline exhibited significant longitudinal cracking during a pressurized test and as a result, as much as 20% of the flow was lost due to leaks. The pipeline was drained and all visible cracks were sealed using typical repair materials available locally. When the pipeline was pressurized again, the repaired cracks again leaked. The leaking at the repaired cracks was most likely due to the increase in the crack width due to the deformations of the pipeline caused by the increase in internal pressure. Given the rigidity of most crack sealing materials, full deformation compatibility between the repair material and concrete could not be achieved, degrading the seal and allowing leaks to reoccur. Figure 2 illustrates typical leaks occurring at two locations along the length of the pipeline during tests conducted at maximum operational pressure.

Moreover, the cracks generated multiple paths for humidity intrusion that reached the steel reinforcement of the pipeline, allowing for corrosion problems that, if not properly addressed, could compromise the structural integrity of the pipeline in the future. Complicating the problem even further was the combination of mountainous topography and the constant tropical rains. Since most of the pipeline is buried underground, water draining down the mountains keeps the surrounding soil constantly saturated and generates seepage pressures. In fact, with the pipeline empty, seepage water was observed draining through some of the longitudinal cracks (see Figure 3).

(Insert photo 3 here)

(Insert photos 2a and 2b here)

Figure 2: Leaking after conventional crack sealing

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Figure 3: Seepage water draining into pipeline It was at this point that QuakeWrap’s Mexico (QWM) office was contacted for engineering consultation to repair the longitudinal cracks. A site visit was quickly arranged for one of QWM’s structural engineers. The engineer inspected the cracks, reviewed structural plans and available local engineering

reports pertinent to the leak issues, and indentified the main cause of the problem. In order to arrive at an optimal engineering solution, all the problems mentioned above needed to be properly and simultaneously addressed. An additional consideration was the urgency of minimizing the time required to implement the repair, since – obviously – the power plant could not produce electricity while the pipeline was shut down. The solution that QWM implemented is discussed in some depth, as follows. SOLUTION TO THE PROBLEM The application of FRP linings requires a certain amount of preliminary work to the pipe surface in order to maximize contact and bond strength between the substrate and the FRP. Therefore, pressure washing, as well as some patching and/or grinding must take place in the areas targeted for lining with FRP. In the case of the El Encanto pipeline, the amount of preliminary work was atypically large, since the cast in place construction process caused significantly more surface irregularities than those associated with the more traditional precast pipes, such as Prestressed Concrete Cylinder Pipe (PCCP). Figure 4 shows the typical condition of the interior surface of the

Western Society of Trenchless Technology - Trenchless Review - 2009

pipeline prior to initiating prep work activities. Evidence of cast in place procedures can be observed, such as construction joints, formwork fins, etc. The pipeline was pressure washed with 7,000 psi machines to remove any scour, sediment and curing compounds, or any other substance that could hinder the bond between the FRP and the pipe surface. Figure 5 shows grinding of protrusions on the interior surface of the pipeline.

(Insert photo 4 here)

Figure 4: Initial interior surface conditions of the pipeline

(Insert photo 5b here)

Figure 5: Prep work activities prior to installing FRP lining An FRP lining consisting of one layer of bidirectional glass fabric was designed to provide a humidity barrier, to provide an effective crack control mechanism, and to provide additional hoop strength to account for a significant loss of hoop steel due to corrosion. Since in all likelihood the corrosion process at the reinforcing steel had already started due to the two-way humidity paths occasioned by the existing cracks, the

additional hoop strength provided by the FRP effectively increased the useful life of the pipeline. It should be noted that the humidity barrier is effective against water leaking into and out of the pipe, due to seepage or internal pressure effects, respectively; however, the corrosion of the steel reinforcement will not be slowed significantly as a result of the humidity barrier, since seepage water will continue to provide the means for this process to continue. While nonstructural linings can also provide two way humidity barriers, nonstructural linings cannot account for the loss of structural integrity caused by the ongoing corrosion due to the presence of seepage water. Moreover, the adhered FRP laminate was designed to achieve full deformation compatibility with the pipe as the pipe expands due to pressurization, and the bidirectional orientation of the high strength glass fibers in the fabric guarantees that existing and/or future cracks are intercepted in orthogonal directions providing superior crack control. Nonstructural linings, on the other hand, cannot serve as an effective crack control mechanism. Finally, an epoxy top coat was applied as a cover for all the installed FRP. This coat provides resistance to the abrasion caused by sediment carried by the river water, and additional leak proofing by covering any pin holes remaining in the FRP lining. The coating has a concrete gray color, which facilitates quality control by providing a visual means of verifying that the entire light green-colored FRP lining is fully covered, and that any uncovered spots can be easily detected.

The time urgency associated with the power plant’s imminent start of operations cannot be overstated, and required the development of the entirety of the engineering design, specifications, installation shop drawings, as well as securing very large quantities of FRP fabrics and epoxy resins, pastes and top coats, on a very short schedule. QuakeWrap’s manufacturing plants were placed on accelerated production runs to meet rather tight deadlines, and part of the production was prepared for air cargo transport. A technical team of two structural engineers and three field supervisors traveled from QWM to Costa Rica to oversee the project and train the local installation crews. A technical team fluent in Spanish was a must in order for the job to run smoothly. INSTALLATION PROCEDURE The 5,742 ft long pipeline had four lateral access points at the locations of relief valves, with spacing ranging from 1,000 ft to 1,500 ft. These 24” x 24” access points (see Figure 6) were used to supply FRP materials, tools and equipment to four installation stations inside the pipeline.

(Insert photo 6 here)

Figure 6: Typical access point The installation direction was opposite to the flow direction to prevent the joints in the FRP lining from being lifted and detached by the water flow. Each

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(Insert photo 7c)

Figure 7(c) Transition between top and bottom half installation

(Insert photo 7d)

Figure 7(d) Detailing of lining installation installation station consisted of a 5-man crew inside the pipe 07-2009 Advertisement WESTT.indd 1 applying the FRP lining to the pipeline’s interior walls, and another 5-man crew performing support activities such as transporting the rolls of lining material from the access point to the installation point, cutting and preparing the FRP rolls, etc. Figure 7a illustrates the application of an epoxy paste to the top half of the pipeline; the main purpose of the paste is to prevent peeling due to the weight of the saturated FRP fabric, and to seal the surface to prevent excessive absorption by the dry concrete surface of the epoxy resin from the saturated FRP fabric. Figure 7b shows the installation of the first roll of FRP lining material at one of the installation stations. The access point is clearly visible on the lower left portion of the figure. Figure 7c shows the transition between the top and bottom half installation. Notice that there is no epoxy paste used in the lower half. Since gravity effects in this area tend to hold the FRP fabric in place, only a seal coat of epoxy resin was used to prevent exces-

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sive absorption from the saturated Specially designed construction fabric. Figure 7d illustrates overjoints (see Figure 8) were pre7/28/2009 10:55:15 AM lap and fabric edge detailing. pared at the starting point of Detailing is done with epoxy paste each installation run, which also and/or epoxy resin to feather became the end points of the down edge fibers, and to secure in installation front that started at a place the overlaps in the lining. downstream access point. The

(Insert photos 7a)

joint was later sealed with an epoxy paste. Nowhere in the 5,742 ft length of the pipeline were FRP lining edges left exposed to peeling from water flow, maximizing the water tightness of the installation.

(Insert photo 8 here) Figure 7(a) Epoxy paste installation on top half of pipeline Figure 8: Construction joint of FRP lining (Insert photo 7b)

Figure 7(b) Installation of FRP lining

The average rate of production of each of the four installation stations was 2,500 ft2 of FRP lining installed in an average 8 hour work day. The operation continued seven days per week, allowing the complete installation of approximately 150,000 ft2 of the

Western Society of Trenchless Technology - Trenchless Review - 2009

FRP lining system in 15 calendar days. This also included the application of the epoxy top coat, which, as stated previously, was used to provide abrasion protection for the FRP, as well as to seal any remaining pores in the installed FRP laminate. Figure 9 shows the application of the top coat. The application took place before the lining was fully cured (surface was still tacky on contact) to ensure maximum bond.

(Insert photo 9 here)

Figure 9: Application of epoxy top coat The FRP lining installation was completed on July 8th, 2009, and pressurized test runs were successfully completed. Figure 10 shows a completed lining installation prior to testing.

More than one mile of a 7-ft diameter pipeline was successfully retrofitted to its original condition in three weeks (one week of prep work and two weeks of FRP lining installation). The FRP lining is expected to require no maintenance and to have a useful life that will match the pipeline’s operational lifetime. CONCLUSIONS The FRP retrofit of the 5,742 ft long and 7 ft interior diameter, cast in place concrete pipeline at “El Encanto” Hydropower plant in Costa Rica is the largest reported FRP pipeline retrofit job completed to date in the world. The features unique to the project, such as the extent of the prep work required to assure a smooth surface free of the irregularities caused by the cast in place procedure; the significant changes in the vertical and horizontal alignment of the pipeline due to the mountainous topography and that required solutions to challenging engineering issues relative to the layout of the FRP lining; the training of local installation crews and the urgent need to minimize downtime of the power plant, made the successful completion of the project an outstanding engineering achievement. The fact that over one mile of a large diameter pipeline can be retrofitted to its original condition with minimum downtime and no excavation required, even under the unique challenges mentioned above, is a testament to the versatility and effectiveness of this FRP technology and the experience of the project team.

(Insert photo 10 here) Mo Ehsani, Ph.D., P.E., S.E. is President and CEO of QuakeWrap, Inc. and Professor of Civil Engineering at the University of Arizona. He pioneered the application of Carbon FRP in repair and retrofit of structures in the late 1980s, and he is internationally recognized as an expert on the subject Carlos Peña, M.S., P.E. is President and CEO of QuakeWrap México and Professor of Civil Engineering at the University of Sonora. He has more than 25 years of experience as a structural consultant in México and the U.S.

Figure 10: Completed segment of the FRP installation Western Society of Trenchless Technology - Trenchless Review - 2009

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The 2009 International No-Dig Show A RecordBreaking Success Angela Ghosh NASTT Assistant Executive Director. By any measure, the International No-Dig Show, March 27 – April 2, 2009, in Toronto was a success. The record-setting event brought together 1,900 attendees and 124 exhibiting companies from 43 countries around the world. The exhibition hall with more than 243 – 10x10 booths sold was the largest in No-Dig’s history and showcased products from around the world. There were 140 technical papers presented over five concurrent tracks. International speakers came from as far afield as Denmark, France, Germany, Italy, Japan, China, Poland, Netherlands and the United Kingdom.

side of the Atlantic. NASTT and ISTT worked together again in Washington in 1992, in New Orleans in 1996 and in Las Vegas in 2003. The event in Las Vegas built on Ray Sterling (center) accepts the ISTT Gold Medal and NASTT's past achieveChairman's Award for Outstanding Lifetime Service. ments and plus members of the Program was a great success despite conCommittee and other countless cerns about the SARS outbreak in volunteers who have put together Hong Kong. a truly outstanding technical pro“Today we meet in Toronto at a gram and exhibition,” said time when world leaders are Downey. meeting for the G20 summit in

The gathered international community enjoyed an exceptional six days of education, solution sharing and peer networking. The purpose of the conference was to showcase the latest in trenchless innovations and provide educational and networking opportunities with leading experts on a global scale.

London. Challenging times lie ahead for our economies but in many parts of the world our industry is going take a lead in rebuilding our infrastructure from the bottom up. I’ll bet we have more fun than the guys in London,” said Dec Downey, ISTT Chairman in his opening address.

Joe Loiacono was presented with an appreciation award for his hard work and dedication for serving as Program Chair of the event. He also credited the Program Committee members, session leaders, NASTT and BMI staff, and the attendees “who come and make everything happen.”

“It’s been a real pleasure to work with NASTT in the preparation of this event. A lot of hard work has gone into putting together a truly international technical conference for which we can all be proud. I would personally like to thank Joe Loiacono, the Program Chair of this year No-Dig, and the forty

“You are the ones, year after year, who provide our industry exhibitors and researchers with the problems and issues which they use to invent new products and technologies or improve the existing ones. You are the ones who make this industry grow by your networking and sharing of experiences at No-Dig. Thank

The International No-Dig Show was co-sponsored by the International Society for Trenchless Technology (ISTT). This is the fifth international No Dig event to be held in North America. The first in Washington in 1988 positioned trenchless technology on the map on this

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Western Society of Trenchless Technology - Trenchless Review - 2009

2010 No-Dig Show Program Chair Mark Hallett poses with 2009 Program Chair Joe Loiacono. you again!” said Loiacono. Chris Brahler, NASTT Chair, highlighted the conference’s successes in his closing address. “We embarked on a technical conference and expo that broke all NASTT records for number of papers presented, for number of exhibitors, and the number of attendees. As if that wasn’t enough, we had a terrific turnout at the Educational Fund Auction raising over $40,000,” said Brahler.

All 13 past and present NASTT chairs attended the show this year.

inspired and energized!” said Brahler. In 2010, NASTT will return to the birthplace where it all began

– in Chicago – to hold the next No-Dig Show and to celebrate its 20th anniversary. Conference organizers have many special events planned including a historical timeline and exhibit to showcase the founding members. The conference theme of “Rebuilding North America’s Underground Infrastructure using Trenchless Technology” will prove to be timely and relevant given that throughout North America there is a renewed focus of infrastructure investment. The ISTT will host its International No-Dig in Singapore, Nov. 10-13, 2010. Visit www.istt.com for more information.

“Our Gala Dinner and reception was really first class in every respect, and there we recognized outstanding projects and innovative products. We honored the life achievements and contributions of many people including countless volunteers who are responsible for putting on this conference.” “Yes, this has been an extraordinary week filled with many memories shared with good friends, and new approaches and practices learned. My hope is that everyone comes away from the 2009 No-Dig conference feeling Western Society of Trenchless Technology - Trenchless Review - 2009

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Rehabilitating a Sewer Pipeline Within an EcologicallySensitive Site Russell Bergholz, PE, Dudek Engineering & Vipul Joshi, Dudek Engineering The City of Carlsbad, CA Aqua Hedionda Interceptor Sewer is located along the northern shoreline of the environmentallysensitive coastal Aqua Hedionda Lagoon and wetlands. Years of ocean tidal flow has eroded the lagoon’s shoreline, placing portions of the old 24-inch diameter asbestos clay pipeline underwater and making access for inspection and maintenance impossible. The site had both environmental and technical impacts on the project approach:

• The sensitive lagoon and wetlands necessitated a collaborative project team of environmental specialists and engineers to develop a feasible solution that could be permitted. The approach proved to be successful in avoiding costly environmental mitigation delays by streamlining design and necessary permitting. • The invert elevation of the sewer near mean sea level was

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fixed by the upstream and downstream tie-in elevations of the existing interceptor sewer. Ground elevations rise moving northerly from the edge of the lagoon, making the sewer deeper the further north the sewer was realigned. Oftentimes when sewer depth exceeds approximately 15-feet, trenchless installation methods start becoming economically and environmentally advantageous. Horizontal Directional Drilling (HDD) is one trenchless method for sewer systems generally limited to force mains, inverted siphons and steep vertical alignments, where the need for highly accurate pipe grade required for gravity flow is not necessary. Microtunneling methods opened up new opportunities for wastewater agencies to take advantage of trenchless methods when accurate control of line and grade are necessary. The Carlsbad project is a good example of how microtunneling trenchless methods can be applied to a challenging infrastructure project, particularly when the site is impacted by environmental considerations.

ENGINEERING DESIGN ENVIRONMENTAL PERMITTING COLLABORATION The initial project concept was to protect the pipe in place and improve access for maintenance. The design was to include a gabion wall (caged rip-rap) and crib walls for slope protection that would facilitate the construct of an access road along the lagoon bank. Initial engineering design concepts were provided to biologists. The biologist’s evaluation indicated that this design would have a very large construction area and impact footprint across the sensitive native habitat and would require time-consuming and costly off-site mitigation, including creation of off-site wetlands that requires a five-year monitoring period. The ability to get such a project permitted through the various state and federal agencies was considered very unlikely and the rip-rap concept was abandoned. A shoreline protection wall was then considered instead of slope protection. The design included the utilization of “pressed in” sheet piles along the shoreline and partially in the lagoon to reduce the potential for sediment and runoff during the excavation from reaching the lagoon and allow construction of the maintenance road. The project was approved by all city, state and

Western Society of Trenchless Technology - Trenchless Review - 2009

federal agencies – except for the California Coastal Commission. The Commission indicated it would reject a project to construct a manufactured permanent shoreline wall along the natural lagoon. With the restrictions now clear on what type of project could receive environmental regulatory permits, the City asked Dudek to develop a trenchless design as it would allow the project to proceed over “existing disturbed areas” (dirt roads, graded lots). Initially trenchless methods were ruled out due to cost, but the combined construction and mitigation measures required to build the access road were extensive, making trenchless an economically viable solution. By installing the new pipe trenchlessly, the native environmental impacts related to previous solutions were significantly reduced.

While a full-blown environmental impact report was required and executed for the second concept – the shoreline protection wall – the trenchless technology approach needed only a mitigated negative declaration under the California Environmental Quality Act (CEQA). This meant the application could be streamlined and obtained in less time. All public agencies, including the California Coastal Commission, approved the project to proceed.

pipeline. The existence of groundwater, the required pipe size, and the length of bore were also design considerations that favor the use of microtunneling.

PRECISE ALIGNMENT, SLOPE REQUIRES MICRO-TUNNELLING Microtunnelling was the only trenchless method viable for the project. Microtunnelling installation allows for highly accurate horizontal and vertical control, critical for a large gravity sewer

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The microtunneling operation would require the use of intermediate jacking stations (IJS) due to the length of the drill and the requirement for man-entry to install the IJS. Therefore a 42inch diameter steel casing was designed. Because of concerns of “increasing capacity” the internal carrier pipe was not allowed to be increased during the project. The option of shorter jacking stations with more intermediate manholes was briefly considered but ruled out due to the increased environmental impact that would occur along the alignment. Houses and other structures in the alignment made an entirely straight alignment impossible. To solve the problem, an offset or “hinge point” was set roughly halfway along the 1,800 feet long alignment. A central jacking pit 15-feet in diameter was drilled with a screw auger approximately 40-feet deep. The jacking pit was shored with a cylindrical corrugated metal pipe installed vertically. Receiving pits located at each end of the project were approximately 15-feet deep and installed in a similar fashion.

Intermediate Jacking Stations allow the extended drilling length by reducing the jacking forces. Two 900-feet long microtunneling bores were construct-

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ed, each originating at the central “hinge point” jacking pit. Although the carrier pipe can be jacked without a casing with microtunneling methods, the 24inch carrier pipe size for Carlsbad was not large enough to allow use of IJS. The steerable microtunneling machine was kept on line and grade during installation using downhole video monitoring of a laser projection on a microtunneling machine mounted target. The first 42-inch diameter steel pipe microtunneling bore was completed from the “hinge point” jacking pit to a receiving pit. After completion of the first 900-feet long leg, the jacking equipment was repositioned in the hinge point jacking pit and the second 900-feet long leg was installed to a receiving pit at the opposite end of the project. After installation of 24-inch clay carrier pipe with both legs of casing, the jacking pit and receiving pits will be converted to permanent maintenance access manholes. To reduce bidding and contractor risk, soils testing was performed at the hinge point jacking pit and at each of the two receiving pits to determine the existence, size, quantity, and hardness of cobble or rock. Neither cobble nor rock was evident. This allowed a baseline for design and bidding to be established, including choice of microtunneling face to match the existing conditions. An additional challenge was designing and constructing water-tight receiving pits at both ends of the pipe because they were 15-feet below the surface, which is approximately 13-feet below mean sea level. The contractor utilized the same method for the receiving pits as the deep

hinge point pit, installing a 15foot diameter CMP shaft and concrete base.

After installing the steel casing pipes, the elevation of the pipelines were surveyed to confirm the proper slope was maintained. It was discovered that the vertical alignment had shifted considerably during the drilling operation. Start and end elevations were accurate, but sections of the alignment had moved vertically off grade and created rises and sags. The installation of the carrier pipe within the casing was critical to ensuring there were no flat spots or rises in the final pipeline invert. Because the difference in casing inside diameter and carrier outside diameter was approximately 12-inches, the contractor had the flexibility to precisely place the pipe through the casing to maintain an acceptable vertical grade for proper hydraulic performance. In the upper reach of casing, the contractor was required to utilize a thinner walled fiberglass reinforced concrete pipe to allow the pipe to maintain the proper slope within the casing. Steel rails were welded to the invert of the casing to allow the carrier to be slid into place at the precise slope. The annular space around the carrier pipe will be filled with grout.

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the birds were de-sensitized to a certain noise levels. Second, the trenchless construction technique meant that the week spent drilling the vertical hole for the hinge point would be the noisiest period. The months spent microtunnelling would not generate substantial noise.

ENVIRONMENTAL CONSIDERATIONS DURING CONSTRUCTION The project’s environmental permits established conditions under which construction could proceed. Native habitat was contiguous to the approved work site so biological field monitors were required to ensure grading for pads and excavation of tunnels didn’t impact the habitat. Early communication was established at the project kickoff meeting so that: 1) the contractor’s plans for addressing habitat protection were reviewed and approved by the biologists and 2) the biologist’s plans for monitoring and the potential consequences of detecting nesting birds, for example, were reviewed and discussed with the City and the contractor all occurring prior to start of construction and therefore minimizing delays. Start of construction preceded by just two weeks the beginning of breeding season for the federally-endangered California gnatcatcher. It wasn’t surprising that biologists on a site survey located active nests within 500-feet of the construction site. The biologists

were able to negotiate an agreement with the U.S. Fish and Wildlife Service and California Department of Fish and Game to have a 40-foot high sound wall installed around the construction zone to mitigate the impact to the birds. On-going nest and noise monitoring was conducted to ensure that breeding was successful despite construction noise. For several reasons biologists were able to receive a waiver from the requirement that noise levels stay below 60 decibels. First, the construction site faced a freeway so

ABOUT THE AUTHORS Russell Bergholz, P.E., is a senior project manager with Dudek. Mr. Bergholz is responsible for the management and engineering of waterrelated system master plans and infrastructure design projects. Vipul Joshi has over 10 years’ professional experience as a biological consultant specializing in botanical surveying, permit acquisition, permit compliance, and project management. Mr. Joshi also has extensive experience in managing constraints analysis, entitlement processing, permit acquisition, and biological construction monitoring for a variety of public and private projects.

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Western Society of Trenchless Technology - Trenchless Review - 2009

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Trenchless, To Go Robbins SBU Makes 72-hour Deadline for Urban Water Project Desiree Willis Vulnerable building foundations. High-traffic roadways. Residential properties. Existing utilities. Urban trenchless projects require an extra degree of planning and often have schedule limitations. A recent project in San Francisco California, USA was no exception: Contractor Pacific Boring, Inc. had just 72 hours to excavate the first 24 m (80 ft) of a 90 m (300 ft) long trenchless crossing underneath high-volume rail tracks. The trains, for the Bay Area Rapid Transit (BART) system, could only run on reduced speed for one weekend and steep penalties could be enforced if regular train operation was impacted. The project is an example of the increasing use of trenchless technology in densely populated areas. Not only did the crossing undercut the BART tracks, but also a 70 m (230 ft) long section of California’s Highway 280. Line and grade underneath the structures needed to be accurate within 300 mm (1 ft) in predicted hard rock, requiring a specialized cutterhead rather than conventional Auger Boring Machine (ABM) cutterhead. The project team opted for a 1.5 m (60 inch) diameter Robbins Motorized

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Small Boring Unit (SBU-M) to get the job done—a type of hard rock, trenchless boring machine mounted with disc cutters. PROJECT OVERVIEW Located in southern San Francisco, the crossing is part of a 7.0 km (4.4 mi) long back-up water main that will span across town. The new line is part of the East/West Transmission Project for the San Francisco Public Utilities Commission (SFPUC)—a scheme that will build in redundancy for several key water lines

in case of emergencies such as earthquakes or large-scale pipeline failures. “This region is semi-arid and does not have readily available water supplies. All the supplies are actually ground water that is piped in from the Hetch Hetchy reservoir located in the Yosemite National Park 480 km (300 mi) away,” said Stephen Martin, Construction Inspector for the San Francisco Water Department. The East/West project connects San Francisco’s two main reservoirs, allowing water to be piped in from the eastern

The 1.5 m (60 inch) diameter Robbins SBU-M completed a 72 hour deadline in San Francisco, California.

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side of the city in the event of an emergency. “Most of this $4.56 billion project is allocated to pipelines. We have some smaller lines utilizing open cut with jack and bores, but this is the most important backup pipeline we have in the city,” said Saed Toloui, Project Manager for SFPUC. The East/West pipeline, at a cost of USD $23 Million, is using one of San Francisco’s largest pumping stations, which underwent testing in May 2009. SFPUC conducted thorough geological testing including bore holes along the entire pipeline, as well as both conventional and horizontal bore holes for the Highway 280 crossing. Construction began on the pipeline in February 2007, requiring open cutting of city streets by general contractor Ranger Pipelines, Inc. By January 2009, the entire pipeline had been open cut and installed minus the 90 m (300 ft) long crossing. CHOOSING THE MOTORIZED SBU Pacific Boring, Inc., an auger boring and tunneling contractor from Caruthers, California, was sub-contracted for the crossing and began site preparation in Autumn 2008. The company had already completed two shorter bores using an Auger Boring Machine and conventional soft ground head for the project. Ranger Pipelines was responsible for excavating the 4 m (12 ft) wide by 12 m (40 ft) long launch pit for the machine. During pit construction, crews hit much harder rock than anticipated

A California crossing using a Robbins Motorized SBU was excavated beneath a local highway and rail tracks nearby residential properties. (about 97 MPa / 14,000 psi UCS), as well as a mixed ground conditions of rock and soft ground at a depth of 6 m (20 ft). The unexpected geology prompted the crew to lower the boring pit another 6 m (20 ft) into more stable rock. The project team, consisting of the SFPUC and consultant Jacobs Associates in conjunction with Pacific Boring, changed the initial contracted method, which specified pipe ramming. Pipe ramming was deemed inappropriate for the hard rock. “After encountering very hard greywacke rock, we determined a large diameter TBM or other method would not be successful. We wanted a more versatile and accessible cutting head, and Pacific Boring suggested Small Boring Units,” said Toloui. “We had heard about SBUs from other contractors who had successfully used them, such as Midwest Mole. We were just

waiting for the right project with the right geology,” said John Iles, Vice President-Operations of Pacific Boring. The contractor also selected an SBU-M over other technologies such as conventional auger boring. “We didn’t feel comfortable going three hundred feet with augers taking all of the cutting torque,” said Iles. HOW IT WORKS: MOTORIZED SMALL BORING UNIT (SBU-M) The Robbins SBU-M is a manned entry, hard rock boring machine specialized for use on long utility installations (90 m / 300 ft and over depending on geology) and on crossings with specific line and grade requirements. The SBU-M is used with a standard auger boring machine or pipe jacking unit and is mounted with disc cutters to excavate rock from 25 to over 175 MPa (4,000 to over 25,000 psi) UCS. In mixed ground, the cutterhead may feature a combination of single disc cutters, two-

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row tungsten carbide insert cutters, and/or carbide bits. At machine launch, the SBU-M is welded to the lead casing. An inshield motor and drive train provides torque to the cutterhead, while forward thrust is provided by the ABM through the casing. Spoils are removed using a small invert auger inside the casing. The machine can be steered throughout the drive from an operator’s console inside the rear shield. Line and grade are controlled using articulation cylinders and adjustable stabilizer pads, while a laser targeting system provides accurate monitoring of the machine’s position. CROSSING EXCAVATION Excavation began on a 24-hour basis on Friday, January 31 2009. Pacific Boring was given until Monday morning on February 2 to make it past the 21 m (70 ft) mark and the BART tracks. The small construction site (12 m / 40 ft wide by 24 m / 80 ft long) on a residential street in the city was about 5 m (15 ft) from a row of houses, and prompted the contractor to move residents to a nearby hotel during the weekend launch. The SBU-M, utilizing 292 mm (11.5 inch) disc cutters, began excavating the Franciscan formation consisting of greywacke rock. “After we got through the initial section of hard rock, we ran into a muddy fault zone for about 5 m (18 ft) until we got back into the fractured rock we were expecting,” said Iles. The softer fault zone, consisting of fractured rock and hard pan, allowed the machine to advance at a rate of about 300 mm (1 ft) every 30 minutes. Once back

into hard rock the machine averaged about 1 m (3 ft) per hour. Every 6 m (20 ft), crews lowered a new section of 1.5 m (60 inch) Permalok® steel casing for installation. Muck was removed using a crane with a hydraulic clam. By Monday morning, the Robbins SBU-M had advanced within the 24 m (80 ft) project goal. After the tight initial schedule, crews resumed normal 10 hr boring shifts. The machine encountered a mixed face of clay and rock in the ensuing weeks, requiring grill bars to be added to the muck buckets on the cutterhead. Despite the difficult ground, the SBU-M completed its crossing within the project schedule on March 16, 2009. POTENTIAL IN URBAN SPACES Urban use of SBU technology is on the rise, requiring only the space of a standard auger boring

pit, which can be used in close proximity to residential structures without compromising foundations. “SBU technology definitely has potential for urban projects in California in the right type of rock,” said Iles. Though many factors such as construction site size are determined by the geology and design consultant, some generalizations can be made. “The pit size can be as small as 11 m (36 ft) long by 3 m (10 ft) wide for a 600 mm (24 inch) diameter SBU. At minimum, as far as the site size, the contractor will need space for lifting equipment and spoil removal equipment, in addition to support equipment such as welders and small tools,” said Chris Sivesind, SBU Division Sales Engineer-West & Central U.S. Overall, the SBUM/ABM or SBU-A/ABM setups need a larger shaft or pit than microtunneling or standard soft

San Francisco’s high volume rail tracks imposed a 72-hour deadline on a trenchless crossing in January 2009. Photo credit: Steve Gallyer, Pacific Boring, Inc. Western Society of Trenchless Technology - Trenchless Review - 2009

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ground pipe jacking. However, the surface area required to support a microtunneling system is larger than either an SBU-M or SBU-A set-up with ABM. Distance to structures, such as houses or commercial buildings, depends on the ground conditions. In hard rock, the method of pit excavation is typically by drill and blast or rock hammer, which requires some distance to sink a shaft near a structure. The softer the ground, the less critical it becomes to maintain distance from structures due to common methods of ground stabilization such as secant piles. The amount of cover necessary also depends on the geology and pipe diameter, though most hard rock rail crossings require a minimum of 900 to 1,200 mm (3 to 4 ft) of cover.

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A 1.5 m (60 inch) Robbins SBU-M completed San Francisco’s East/West Transmission Main Project, breaking through in March 2009. Photo credit: Steve Gallyer, Pacific Boring, Inc.

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Sharing Technologies Together Roberts McMullin, URS Corporation, PUG Secretary The Northern California Pipe User’s Group (PUG) is a non-profit organization that focuses on the distribution of education in the water/wastewater pipeline industry. Since 1992, PUG continues to share information and technology to its current 57 members, which are composed of municipal agencies, engineering consultants, suppliers, and manufactures. PUG conducts monthly meetings, annual seminars, website updates, training courses, and news notifications to its members in an effort to advance education in the pipeline industry. PUG meetings are regularly held at the Brown and Caldwell office in Walnut Creek, California on the third Tuesday of each month. At these meetings, members are informed of PUG related events and current news related to the pipeline industry. During these meetings, members are encouraged to discuss current projects or pipeline issues for forum response and comment from attending members. Following the discussion of current projects, presentations are given to introduce new technologies related to water/wastewater pipelines. Previous presentations from 2009 include: horizontal directional drilling technology by the HDD Company, pipe busting with vitrified clay pipe by TT Technologies, managing geotech-

Pipe User's Group Logo nical risk on trenchless projects by DCM/GeoEngineers, pipeline condition assessment for water/wastewater systems by Pure Technologies, coating and lining solutions for pipeline rehabilitation by Sprayroq and Inland Pipe Rehabilitation / RePipe, and asbestos concrete pipe (ACP) removal by the Bay Area Quality Management District. With great presentation topics such as these, PUG members are given the opportunity to learn the current trends in technology and issues related to the industry. PUG’s annual technical seminars have been popular wellattended functions for the past 17 years. In February, 2009 PUG conducted its 17th annual sharing technologies seminar in Berkeley, California. Industry professionals, including PUG members and non-members alike attended the all day event covering eight industry related presentations selected by the PUG Board of Directors. The Keynote Presentation to start the event was on aging water infrastructure by Anthony Tafuri from the

United States Environmental Protection Agency (USEPA). Other presentation topics included: Honolulu force mains condition evaluation, new cutter-soil mixing technology for construction of microtunnelling shafts for Mokelumne River crossings, Fairwood Interceptor Project in King County Washington, new innovative maintenance technologies, large diameter deep sewer pipeline under urban constraints for the Sacramento County Regional Sanitation District, tunnelling project for Central Contra Costa County Sanitary District, and water transmission pipeline design and construction for the Nevada Irrigation District. Following the informative presentations, two lucky attendees were drawn to win a Nintendo Wii or satellite radio during the seminar raffle. PUG recently updated their membership website to improve the layout for user interface. The new website can be accessed at www.norcalpug.com. The website contains meeting information for agendas, minutes, calendar

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events, field trips, seminars, workshops, and training courses. Also included is a photo gallery from previous field trips and meetings, industry resources, and membership lists. PUG is currently exploring the prospect of offering on-line payment options through the new website, which would allow flexibility for our members when registering for training courses, annual memberships, and the annual seminar. The website also acts as an interface for potential new members that want to learn more of the great opportunities with PUG. PUG offers excellent training courses for members and nonmembers to take advantage of every year. The 2008 training course took place at the Central Contra Costa Sanitary District office in Martinez, California. The training course was an 8hour Cured-in-Place Pipe (CIPP) Good Practices Course administered by North American Society for Trenchless Technology (NASTT) Instructors. The course provided an in-depth overview of wastewater mainline and lateral pipe rehabilitation using CIPP from the planning and design to project completion. For 2009, PUG is planning another 8-hour training course in October, cosponsored by the Western Regional Society for Trenchless Technology (WESTT). Again pulling from NASTT’s selection of courses, this year’s course will cover New Installation Methods Good Practices. The course will address trenchless methods of installing new pipe and pipe casing. The trenchless methods will include auger boring, pipe ramming, pipe jacking, and the pilot tube method. For more information on the upcoming training course, please visit our website at www.norcalpug.com.

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2009 Annual Seminar Earlier this year, PUG conducted a survey with its members to compile bid results from the first quarter of 2009. The review involved the comparison of low bid results for current construction projects to engineering cost estimates. The low bid results were on average 28% below the engineer’s estimate for a total of 54 project bids averaged. Following the survey, PUG provided this information to its members to help keep on the pulse of the current economic times and the associated impacts to our public engineering projects. PUG also notifies its members of free webinars for on-line educational opportunities and upcoming conferences related to the field. PUG’s motto is Sharing

Technologies Together and our goal is sharing current technologies with industry professionals while learning together from experience to build a better future. PUG would like to thank its members and past presenters for all of the great support and participation throughout the years. We encourage all readers to join us at a monthly meeting and share a technical experience with us as we make every effort to expand education in the pipeline industry. Roberts McMullin works for URS Corporation in Oakland, California and has over 6 years of Civil Engineering Experience. Roberts currently acts as Secretary for the Pipe User's Group.

2008 Ameron Manufacturing Plant Field Trip

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Pipe Bursting Operation In West L.A. Proves Advantageous Keith Hanks, Richard Pedrozo, Mina Azarnia, Art Khachikian, & Teresa Cajahuaringa PROJECT This project upsized 520 feet of 6” sewer using HDPE pipe and static pipe bursting. HISTORY The City of Los Angeles (the City) with its population of more than 4 million maintains and operates more than 6,500 miles of sewer pipe line. In October 2004, the city agreed to a seven year program of removing, replacing, and rehabilitating old secondary sewers as part of a Settlement Agreement. This project requires rehabilitating or replacing an average of 60 miles of sewer per year. The secondary sewers are small sewers that range from 6 inches to 15 inches in diameter. The group of engineers who evaluate the condition of the existing sewer are part of the Secondary Sewer Renewal Program (SSRP). The SSRP engineers’ decision to rehabilitate or replace the old sewers is based on root intrusion, structural defects, corrosion, outdated structures, or lack of capacity in the sewer lines. The poor conditions of existing pipe necessitates to replacement in most cases. Cracks and holes shown in Figure 1 are examples of structural defects. Root intrusion shown in Figure 2 is a common problem at sewer lateral.

Figure 1

Figure 2 METHODS The repair methods that are being employed by the City include open trench for removal and replacement and lining for rehabilitation of existing sewers. The SSRP group is now starting to use other trenchless methods such as pipe bursting with HDPE pipes to upsize sewers of 6 inches to the standard of 8 inches. This method is especially convenient compared to open trench when the sewer reach is located in difficult access areas such as in private properties where structures such as garages, pools, walls, and limited space can obstruct the work. MATERIAL USED The most common material used for secondary sewer pipes is vitrified clay pipe (VCP) because of its high strength, long durability (as long as 100 year life span) and corrosion resistance. The disadvantage of this product is root intrusion through pipe joints. The standard length of VCP pipes are about 3 to 6 feet per section. The pipe product used to install a new pipe using pipe bursting is often high density polyethylene (HDPE) solid wall pipe. This material is an approved material by the city of Los Angeles for use in the sewer system. It passed stan-

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dard tests such as initial tensile strength and elongation, initial flexural modulus, specific gravity, impact strength, apparent cell classification, and the pickle jar test. The length of each pipe section is up to 40 feet long and joints are fused, allowing a seamless pipe to be installed between maintenance holes. This prevents future root intrusion through joints compared to the standard clay pipe section of 3 to 6ft. In secondary sewer reaches this can typically range from 200 to 400 ft long, or longer. STAGING AREA AND TRAFFIC CONTROL Allocating a staging area for the machinery and equipment is a critical part of the project. In this project, a staging area was allocated to fuse the HDPE pipe sections onsite. Also, the staging space was used for equipment set-up. Coordination with the Department of Transportation was necessary to obtain desired feasibility and constructability. The traffic control areas incorporated street closures, detour signs and street parking restrictions. Figure 3 shows how an alley was used as the staging area as the streets surrounding the sewer reach were closed and no-parking signs were placed on public streets prior to construction.

Figure 3 PROCEDURE The secondary Sewer Renewal Program (SSRP) group decided to use pipe bursting to upsize the existing 6” Vitrified Clay Pipe (VCP) sewer line to an

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8” High Density Polyethylene (HDPE) pipe. For this operation a “Launching Pit” was excavated at the point of entry for the HDPE pipe, and a receiving pit was excavated at the ending point. A hydraulic machine was placed in the Receiving Pit to establish a link between the Receiving Pit and the Launching Pit; a chain link was established by inserting one meter long interlocking steel rods (Bursting Rods) through the existing 6” line. An operator fed the bursting rods through the hydraulic machine one at a time and the hydraulic machine pushed the bursting rods through the reach. (Figure 4)

Figure 4 The contractor had a sufficient staging area; neighborhood side streets and alleys proved to have enough space available to fuse all of the forty foot sections of the HDPE pipe prior to the installation. To fuse two sections of the HDPE pipes, their cross sections were shaved clean, 500-degree heat was applied to both cross section areas, and then the two pipe sections were held together for about 15 minutes. There were no chemicals involved in the process of fusing HDPE pipe sections. The bonding of the fused pipes has proved to be water tight and super strong. A heavy cone shaped steel device called the “Expander” was attached to the leading end of the HDPE pipe assembly. The assembly of all fused pipes (520 feet) and the expander was dragged and inserted into the launching pit. During the operation the entire HDPE pipe assembly was pulled by mechanical machinery from the side street to the launching pit, the pipe was dragged, and bent at the corners. One might have expected the fused joints to fail, but the joints held nicely and proved to be very strong. Once the

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HDPE pipe with the expander was in place at the launching pit the cone shaped bursting head was connected to the bursting rod chain which was fed through the receiving pit. (Figure 5)

Figure 5 The next step of the operation consisted of pulling the assembly of the bursting head and expander with the HDPE pipe attached through the 6” VCP. This was achieved by working the hydraulic machine in reverse when pulling the assembly through the existing pipe; the expander burst the 6” VCP to a larger diameter to provide enough space for the 8” HDPE pipe. At this stage, the progress of the operation was speedy, and within minutes, the 6” VCP was replaced with an 8” HDPE pipe. Prior to the pipe bursting process, all house connections were disconnected to prevent them from damage during the bursting operation. When the 8” HDPE pipe was pulled in place, 6” holes were drilled into the newly installed pipe in order to fuse 6” wyes (stubs) on to it at the house connection locations. This was accomplished using a special device, heating both sides of the 8” HDPE pipe and the wye stub leading to the house connection. Then the house connection was established by connecting the stub to the house connection lateral by a couple. ADVANTAGES AND DISADVANTAGES Pipe bursting has substantial advantages over the open cut removal and replacement method. It can be faster, cheaper, more efficient, less disruptive to surface improvements, and creates less harmful

environmental impacts. The cost advantage is especially notable where the cost of open trench increases through extra excavation, shoring, etc. However, these factors have minimal effect on the cost of pipe bursting. The main advantage of pipe bursting over other trenchless rehabilitation methods such as lining is the ability to upsize sewer lines. While lining methods of rehabilitation follow the grade of the existing pipe, pipe bursting can modify it under particular circumstances - to correct unwanted sags for instance. As a result, the feasibility and cost effectiveness of pipe bursting have made this method of pipe renewal very favorable such that the total footage of sewer pipe replacement is growing every year. Pipe bursting can be an ideal method for replacing old pipes in areas where there are no or limited house connections, or where disruption to surrounding utilities, local residences, businesses and the environment are a consideration. HDPE is the most common pipe material utilized in this process since it has an added benefit of smooth inner walls, which facilitates the gravity flow and prevents the chances of developing stoppages. A comparison was made between the cost of pipe bursting and traditional open cut methods. The price per linear foot of pipe bursting was approximately $ 346.00 and the project could be done in only 3 days, whereas, the price per linear foot of open trench method of sewer replacement was estimated to be $ 520.00 per linear foot. Pipe bursting eliminates up to 85 percent of open cut on the project. We were able to further reduce the cost of the project by entering the bursting equipment through a manhole, which resulted in minimal expenses relating to trench cutting, hand digging, backfill, compaction, and traffic control. The project took place in a residential area in Venice Beach, an ideal setting to highlight the social benefits of pipe bursting as well as the economical benefits. This project proved all of our assumptions about pipe bursting true. The project went smoothly and when we calculated the cost, the figures were impressive and the advantages were measurable. Pipe bursting can be safe for nearby utility and substructure lines and can reduce traffic impact. This method of sewer replacement can be more affordable, especially when it decreases or eliminates the need for expensive excavation and restoration costs.

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Manhole Rehabilitation in Singapore: going the extra several thousand miles in search of the right solution Angus W. Stocking, L.S. Toh Ben Sang Contractors, Pte Ltd, based in the Republic of Singapore, had just landed a huge contract for sanitary sewer rehabilitation in Singapore, more than 55 kilometers of line—that was the good news. The bad news was, the project included hundreds of manholes, the schedule was tight, and manholes were not, at the time, one of Toh Ben Sang’s specialties. Infrastructure in Singapore is held to high standards, and even though the manholes in question were just 10 to 40 years old, they would all require relining. “The oldest were brick lined and in pretty bad shape,” explains Raymond Pang, a project manager for Toh Ben Sang. “Walls were corroded, some of the benching and grout was gone, there was infiltration, and there were cavities that needed filling. The newest were of precast concrete and were not so bad, just a bit of peeling—but they had to be restored as well.” Further complicating matters was the Republic’s tight control of materials and processes used for infrastructure work—everything must be certified and approved. While investigating solutions, Toh Ben Sang learned about PERMACAST CR-9000, a corrosion resistant mortar based on calcium aluminate cement that is designed to resist biogenic corrosion. “It’s one of the products approved in Singapore, it’s recommended by the WRc Group [a UK-based water consultancy] and we read about it in their manuals,” says Pang. “We decided to give it a try.” In addition to corrosion resistance, PERMACAST

Vehicle set up of permacast system

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mortars are exceptionally dense and strong, so they’re ideal for rehabilitation… but they require skilled application. Typical shotcrete applicators are not suitable for manholes, because high pressure in the tight space leads to ‘rebound’, meaning that concrete sloughs off, leaving a patchy, uneven surface. PERMACAST licensed applicators in the United States typically use the SpinCaster, from AP/M Permaform, to apply the mortar to manholes—the SpinCaster is a pump connected to a mortar-emitting nozzle that is winched in and out of manholes. It’s bi-directional, meaning that the nozzle spins, alternately, clockwise and counter-clockwise. Since half the thickness is applied in each direction (and while being raised and lowered), the PERMACAST is sprayed evenly and doesn’t ‘cast shadows’ in raised parts of the rehabilitated surface, such as protruding bricks. Pressure is modulated just enough to eliminate rebound, but kept high enough to compact the mortar with centrifugal force and insure tight adhesion. Spinning in both directions also applies a smooth coat and eliminates trowel work. The application labor is also straightforward, and only requires a two-man crew—one to mix mortar and tend the pump, and one to operate the winch and spinning nozzle at the ‘business end’. Coats applied are very thin, but applied quickly. This allows precisely engineered thicknesses of new material, depending on the condition of the substrate, but still lets crews move quickly and repair several manholes a day. There is one more advantage to SpinCaster use—since the nozzle is lowered from the surface, and since hand troweling is usually eliminated, employees rarely have to enter hazardous confined sewer spaces. So far, so good: Pang felt that he’d found the right material to apply, and the right application method, but he didn’t know anyone else in Singapore that was using PERMACAST or the SpinCaster - in fact, Toh Ben Sang would be the first licensee in the world’s largest city-state. So Pang and two other Toh Ben Sang employees flew to AP/M Permaform headquarters in Johnston, Iowa for training. “Training

Western Society of Trenchless Technology - Trenchless Review - 2009

Permacast in action

Winch hoistering the spin caster was excellent,” reports Pang. “We were given thorough classroom instruction, and then we were taken to actual job sites, which I really appreciated. It let us see how the products were used on site, and what actual conditions were like. I thought it was much better than classroom training alone.” GETTING TO WORK Back in Singapore, Toh Ben Sang took delivery of the mortar and two SpinCasters and got to work immediately - the research and training phase of the project had put them behind schedule. Fortunately, Pang found that his crews were able to move quickly. “In a good week,” he says, “a team with a SpinCaster was able to rehab up to 30 manholes per week.” The older brick manholes required patching, filling and other repair work, but Pang found that PERMACAST alone was a sufficient repair for the newer manholes, which were peeling and spalling, but still essentially intact. Once Toh Ben Sang got started, they were more than able to make up for lost time. “In fact,” says Pang, “not only were we able to get back on schedule after the late start, we were able to finish before the end date.” In the initial project, Toh Ben Sang rehabilitated a total of 350 manholes. The job was judged to be such a success that more equipment was acquired to outfit a total of four crews and take on more projects, and the company has since completed another project that included rehabilitation of an additional 300 manholes. “We’ve inspected some of our earliest rehabilitated manholes, which are now about half a year old,” says Pang, “and we find that they’re hold-

ing up very well.” The flight from Singapore to the United States is more than 15 hours, which seems like a long way to go in search of a manhole rehabilitation solution. But for Toh Ben Sang, the effort was worth it and they’ve been increasing their investment in this solution. “PERMACAST is a great product, and the SpinCaster has worked really well for us,” says Pang. “We’ll be using them together for a long time.”

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Western Society of Trenchless Technology - Trenchless Review - 2009

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Laser Profiling in Plastic Pipe Ken Lucas, President, Geolyn Pipe Inspection Services Ltd. New pipe installations for sanitary and storm sewers are often required to be video inspected after 30 days from backfilling and again one year after installation to ensure that the pipe meets construction standards and does not have pooling of water in sags or pipe wall compression. As more and more contractors are using PVC pipe for sanitary and storm sewer applications, municipalities are asking for deflection testing of the PVC pipe as part of the inspection process. Deflection testing measures the amount of compression that the pipe experiences after it has been placed and backfilled. BACKGROUND PVC pipe is made of polyvinyl chloride plastic. It is very durable and well suited for waste and storm water applications. There is some concern that after the pipe has been installed and back filled, the pipe will crush and eventually collapse over time.

Collapsed PVC Pipe These concerns led to the development of the mandrel test. A mandrel is a test fixture that generally has 9 fins attached to a body and it is dragged through the pipe with a cable or robot.

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The mandrel is a fixed dimension and is usually either 5% or 7.5% smaller than the inside diameter of the pipe. If the mandrel passes freely through the pipe segment, then the pipe passes the internal diameter check. If the mandrel becomes stuck in the pipe, then the pipe compression exceeds the 5% or 7.5% tolerance. The mandrel has to be pulled back the way it came from and the pipe dug up to relieve some of the backfill pressure. Generally, the 5% tolerance is permitted after 30 days installation and the 7.5% is permitted after one year from the date of installation.

Conventional mandrel being towed by a robot Mandrel testing is a go/no go testing method. It does not provide the amount of deflection that the pipe is experiencing. Furthermore, it can become entangled on intruding pipe connections or turning pipe. Over the past few years, laser profilometry has appeared on the inspection front. Laser profiling projects a 360 degree laser line on the interior wall of the pipe and the image is recorded using conventional video camera.Video images are projected onto a computer screen using pixels to create the image. A standard 640X480

screen has 640 pixels by 480 pixels or 307, 200 pixels. If a 15” pipe takes up 400 pixels, then each pixel represents .03125” per pixel or 26.66 pixels per inch. The video is fed into laser measuring software that takes the image and counts the number of pixels on the image between the top and bottom of the pipe wall. The software then asks for a known diameter to be applied to that pixel count and then calculates how many pixels per inch. The software then applies this measurement to subsequent images to determine the diameter of the circle. The laser software requires the first image to be measured with a tape to give the software a base point. So if a pipe is a 15” internal diameter, the operator tells the software that the first laser ring image is 15” and the software counts pixels. The software then counts pixels on every image thereafter to determine the diameter of the laser circle. Therefore, if the next image has the pipe diameter compressing to 360 pixels, the diameter of the pipe is 13.5” or a 10% deflection. This picture can determine pipe deflection and ovality in the pipe.

Western Society of Trenchless Technology - Trenchless Review - 2009

Laser imaging ring on inside of pipe

The advantage of the laser imaging system is it is a very accurate measuring tool. It provides a very precise measurement of the pipe, not just a go/no go test. Additionally, the laser can be used to track long term compression and erosion of interior pipe surfaces as the inspector can very accurately track pipe diameters over time with multiple measurements over multiple years. The other advantage of the laser system is it does not contact the pipe walls and cannot get hung on connection joints or corners. This permits the inspector the ability to accurately measure the pipe diameter regardless of the amount of deflection. We have seen 500 foot sections of pipe with an 8% deflection within 6 feet of the starting manhole and 10 feet of the ending manhole and the rest of the pipe in between within tolerance. The mandrel would fail the entire run of pipe and force the contractor to dig up the entire 500 feet, whereby the laser would identify the exact locations that needed to be dug up not the entire run. Laser profiling will continue to become the accepted means of compression testing as it is a far superior tool for creating a profile of the pipe versus a pass/fail test.

Laser assembly being towed by robot

Geolyn Pipe Inpsection Services Ltd. is a Calgary, Alberta, Canada based company specializing in inspection of sanitary and storm sewer inspection. Geolyn are experts in laser profiling and robotic inspection services. More can be seen on the company’s website, www.geolyn.ca.

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Conflict Resolution: Unique Design Solves a

Complex Sewer Issue in Phoenix

Arvid Veidmark III, EVP/Sr. Estimator Specialized Services Company (SSC) OVERVIEW Even with the best of technology, not all projects go as well as we anticipate. In order to minimize delays and overruns it is necessary to have a clear understanding of the scope of the project, a good design plan, employ proven pre-construction practices such as S.U.E., and have the wisdom and experience to “expect the unexpected.” On a project in North Phoenix, we discovered that truer words were never spoken. Contracted to install a portion of a regional sewer line, designed to connect to an existing 36-in line downstream, we came across some unusual and technically challenging conflicts. The project began in October 2008. As-built and preliminary field inspections revealed a 42-in CCP water line and a 24-in DIP, neither of which could be taken out of service. Additional as-builts for the area indicated an existing 16-in (DIP) sewer line and an Arizona Public Service (APS) electrical duct bank, which was estimated to be approximately 4-ft below grade-a standard APS depth. PRELIMINARY DESIGN CONFLICTS The 42-in water line posed the greatest design challenge. As-built data provided by the pipe manufacturer, and preliminary pothole information provided by SSC, left no question that the bottom of the 42-in waterline was in direct conflict with the top 6in of the proposed sewer line.

To accommodate this conflict, the engineering firm Kimley Horn & Associates (KHA) designed an atypical but highly effective solution that split the 36-in sewer line into three 18-in diversion pipes at the point of conflict to allow for the transfer of flow below the 42-in & 24-in waterlines (with only 4inches of separation). Two custom junction structures (10-ft x 9-ft) were also designed complete with internal diversion benches and air jumper. This new design required a 78-in casing that would be “notched” the point of conflict to allow it to clear the 42-in water line by 4-in (see fig.1). Flush bell HOBAS pipe was selected as the 18-in carrier pipes, allowing the pipes to be installed at grade and pushed along guiderails welded to the 78-in casing CONSTRUCTION CONFLICTS Preliminary pothole reports also indicated that the 24-in water line was within 4-in of the proposed sewer line. It was initially believed that a vertical realignment would solve the problem. However during excavation of a central receiving pit (see fig.2) to verify elevation of both the existing 24-in and 42-in lines, a dip was discovered in the 24-in line, which also directly impacted the alignment of the proposed sewer line (see fig. 3). Once again, the plans were altered to accommodate a realignment of the new sewer line, this time 15-ft to the north (see fig. 4).

Figure 1

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Figure 2

Figure 3 Figure 6

Figure 4 Construction began with a 36-in auger bore to install the two 12-in air jumpers. The as-built records had indicated that an electrical duct bank existed consisting of six 6-in PVC conduits, housed in 3-ft of concrete. While the original design called for installation the 36-in vent in the slurry just above the duct bank, pre-construction potholing, using keyhole and vacuum technology, revealed two additional conduits in the slurry that were not included on the as-built records. These conduits had been installed by Cox, who had future plans for both conduits and could not be removed. This unexpected problem was resolved by raising the elevation of the 36-in bore to 18-in below the

Figure 5

surface and by installing sweeps on the two conduits, which realigned them just below the 36-in casing (see fig. 5). Upon successful completion of the 36-in auger bore for the air jumpers, two hand tunnels were performed, in separate boring events, to install the 78in casing for the 18-in diversion pipes (see fig. 6). The casing was installed from both the east and west side of the road and met in the middle under the 24in and 48-in waterlines. At this point the casing was notched to accommodate the waterlines and steel plating was welded to the casing under the waterlines to provide the necessary isolation of the sewer lines (see fig.1). The annular space within the casing, which was originally designed to be filled with grout, was filled with sand gravel at the recommendation of SSC, in order to reduce float and maintain grade. The project was completed successfully. CONCLUSION: On this project the value of subsurface utility engineering, including potholing, was definitely demonstrated. However, even with this case the amount of S.U. E. dollars allotted could have been expanded to include slot trenching along the 24-in and 42-in conflicts to confirm alignment and depth early in the design phase. Early information would not have eliminated the conflicts but would have eliminated the time and expense associated with delays and change orders. According to the Federal Highway Administration, for every dollar spent on subsurface utility engineering, over $4.00 is saved during the construction process. This project is a prime example of why it is so important for engineers and other construction professionals to familiarize themselves with and implement S.U.E. practices on every underground installation project, especially large diameter installations in which undocumented conflicts are a routine occurrence.

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Large Diameter Sliplining & Large Diameter CIPP work together to rehabilitate aging interceptor sewers in Albuquerque, NM Michael Rocco, Trenchless Manager AUI Inc. Albuquerque, NM has the same problem as many municipalities throughout the United States and that is old, aging and failing interceptor sewerlines. However, this time the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) took a proactive approach in addressing this problem rather than a reactive approach. It has been common in the past to respond to a sewer collapse, usually on a Friday night, which requires the isolation of the area, major traffic set up and begin to by-pass pump the sewer. When an emergency collapse of a interceptor sewer failure happens, the cost associated are usually a lot higher than a planned sewer rehabilitation project. In December 2008 the ABCWUA took bids on a Large Diameter Sewer Rehabilitation Project for the rehabilitation of interceptor sewers. AUI, Inc out of Albuquerque was the successful bidder on the project. The project consisted of two trenchless rehabilitation methods called Sliplining and the cured in place process (CIPP). SLIPLINING The first trenchless rehabilitation method used was sliplining. The project specifications were to slipline 78”, 54”, 48” & 27” RCP. AUI used two different pipe manufactures to accomplish the sli-

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plining. The 78”, 54” & 48” old RCP pipes were sliplined with the CCFRPM manufactured by Hobas pipe and the 27” old RCP was sliplined with PVC manufactured by Lamson Vylon Pipe.

Figure 2 - CCFRPM Hobas Pipe with TeeKay Couplings at Insertion Pit

Figure 1 - 66” CCFRPM Hobas slipped into existing old 78” RCP The biggest interceptor that was sliplined was the 78” RCP which was sliplined with 66” Hobas pipe (fig. 1). The total footage of 78” RCP that was rehabilitated was 5,234 lf. One of the most difficult jobs in this slipline process was to clean and remove all the silt from inside of the old 78” RCP. AUI subcontracted the cleaning operation to Southwest Sewer Inc. Southwest Sewer removed and hauled to the sewer plant over 1,000 tons of debris that has been laying in the old 78” sewer line. All of the slipline work was done under live conditions without the need for bypass pumping.

The 54” sewer interceptor line was rehabilitated with a 48” Hobas pipe. The total footage of 54” RCP that was rehabilitated was 1,210 lf. This section of interceptor line was located in downtown Albuquerque and thus traffic, pedestrians and business owners were all stakeholders in the construction process. The ABCWUA project manager was Nancy Musinski P.E. 505-7682729. The work downtown went smoothly and was completed in less than a month.

Figure 3 - 44” Hobas CCFRPM at jobsite to be slipped into existing 48” RCP The 48” sewer interceptor was sliplined with 42” Hobas pipe (fig 3). The total footage of 48” RCP

Western Society of Trenchless Technology - Trenchless Review - 2009

that was rehabilitated was 2,209 lf. This section of interceptor was originally installed in 1966 and the pre CCTV inspection revealed extreme exposed aggregate with hanging gaskets. The alignment of sewer line ran through the City of Albuquerque’s Solid Waste Yard. One segment actually ran under a service building, therefore open cut was not an option.

Figure 4 - 24” Vylon Pipe slipped into existing 27” RCP Lastly, the 27” RCP was sliplined with 24” Vylon pipe (fig. 4). The total footage of 27” RCP that was rehabilitated was 3,940 lf. The sections of 24” RCP were also severely deteriorated with the crown of pipe totally gone and soil was exposed. Pre CCTV inspection revealed a total of three active sewer services which were reconnected at depths of up to 18 feet. CIPP Cured in place pipe was used to rehabilitate 48”, 36”, 30”, 18” & 12” RCP. AUI’s subcontractor to perform CIPP operations was Western Slopes Utilities out of Breckenridge, CO.

Figure 5 - 48” CIPP installed into existing 48” RCP The total 48” RCP that was Cured In Place was 3,772 lf (fig. 5). The sewer line was by-passed with 100% back up pumps in order to allow the CIPP process to proceed. Over 5,300 lf of 18” HDPE was used as the discharge line to support the by-passing of the sewer line. The 48” sewer line snaked through backyards of residents and business. One manhole was located in a homeowner’s property. The 30” RCP line that was Cured In Place was a siphon that ran under a major storm drain concrete channel. The depth of the sewer line was in excess of 25’. The 30” siphon had to be dewatered and the cleaning operations became a different animal. AUI subcontracted out the siphon cleaning to Pro Pipe

Services out of Phoenix, AZ. Pro Pipe used a special chain and nozzle combination to break up the grease that was caked on the pipe. The jetter spun the chain to dislodge the grease buildup and clean the inside of the siphon. After the siphon was cleaned and dewatered, the Cured in place process was completed and flows were returned to normal. The 12” CIPP took place under Interstate 40. Interstate 40 runs East/West through Albuquerque and the old sewer line cut across the interstate at a depth of 14 feet. By-pass pumping was accomplished through a series of storm drains under the interstate so the CIPP process could proceed. Once the sewer line was bypassed the CIPP was installed in 6 hours. Western Slopes Utilities installation crews worked productively and efficiently to accomplish the CIPP work on schedule. In conclusion, over 18,000 lf of both Sliplining and CIPP were used as successful trenchless methods to rehabilitated Albuquerque’s aging interceptor sewerlines.

OWNER: Albuquerque Bernalillo County Water Utility Authority (ABCWUA) Nancy Musinski P.E. • 505-768-2729 CONTRACTOR: AUI, Inc. Michael Rocco Trenchless Manager • 505-975-6999 Larry Reeves Project Manager • 505-975-6646 Archie Lucero III Superintendent • 505-975-6820 John Mata Superintendent • 505-975-6819 ENGINEER: Boyle Engineer Corp Charles Leeder P.E • 05-883-7700 SUBCONTRACTORS: Western Slopes Utilities, Inc. (CIPP) Dan Cohen • 970-453-6176 Southwest Sewer Services (Pipe Clean & CCTV) • 505-249-5135 Western Society of Trenchless Technology - Trenchless Review - 2009

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A Trenchless First in Phoenix:

Static Pipe Bursting Teams With NO-DIG VCP Collins Orton, TT Technologies Robert Webb, Project Engineering Consultants Jeff Boschert, P.E.- National Clay Pipe Institute The city of Phoenix, Ariz., recently undertook a large-scale sanitary sewer static pipe bursting program utilizing vitrified clay (VCP) jacking pipe as the replacement pipe material. The GMP for the project was $5,323,524.05. This project represents one of the most significant uses of the static pipe bursting method with new replacement VCP jacking pipe

and demonstrates a commendable level of cooperation between equipment manufacturer, product pipe manufacturer, contractor, engineering firm and municipality. The city of Phoenix has been experiencing tremendous population growth in recent years, as part of the growing southwest region of the country. This

growth has taxed their collection system. The addition of the new I/I design requirements, coupled with the recent population growth and calibration of their sewer model, indicated that the city’s collection system would require immediate upgrades in many locations. The Sanitary Sewer Relief and

Peoria Avenue Pipe Burst- 375 mm (15 inch) to 450 mm (18 inch) VCP

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Western Society of Trenchless Technology - Trenchless Review - 2009

ranging from 3 to 5 feet depending on depth. Existing trench depths range from 10 to 20 feet deep. Dry, dense soil conditions adjacent to the existing trench and the existing sewer pipe alignments, among other minor obstacles, caused some production issues. However, pipe bursting has proven to be a cost effective process for upsizing capacity deficient sewers with VCP.

Project Site Map Replacement Program was developed to tackle these issues. Full pipe replacement and upsizing, diversions and other techniques were considered as solutions to this potential capacity deficiency. The use of trenchless technologies was determined to be a suitable alternative approach to minimize the impact created by all of these construction projects. Pipe bursting was chosen to fulfill the need for upsizing these capacity deficient pipes without open trenching their streets. PROJECT DETAILS The total project consisted of upsizing of nearly 6,400 linear feet of 12- and 15-inch pipe with a 10- to 20-foot depth within major streets with the usual multitude of utilities. Trenchless equipment manufacturer TT Technologies, Aurora, Ill., provided the Grundoburst static pipe bursting equipment and techni-

cal instruction during the design and construction phases. Mission Clay Products, Corona, Calif., supplied the 15- and 18inch No-Dig VCP, which the city preferred. One of the first sections replaced included bursting and replacing 3,938 feet of existing 12-inch VCP with 18-inch VCP. The existing sewer line’s capacity had been exceeded due to growth of the surrounding area. The utility corridor encompassing the existing line was congested with other utilities making open cut construction challenging. Trenchless pipe bursting was ultimately chosen because of the adjacent utilities and concern of traffic disruption. Soil conditions in the area proved to be one of the biggest challenges. The original pipe to be burst was bedded in a soft, dry, silty sand material and installed in a trench width

Utilizing segmented pipe eliminates the need for a long laydown area on the project site as would be required with welded pipe. This is highly beneficial in high-traffic urban settings. Long strings of welded pipe are not inhibiting traffic flow before the bursting operation begins. This is commonly referred to as the cartridge loading method and keeps the jobsite footprint relatively small and compact. This same technique is successful when pulling other types of sectional pipe such as ductile iron and others.

Project engineering consultants ltd. Water & Wastewater Engineers Specializing in: Pipeline Assessment Pipeline Rehabilitation Trenchless Engineering GIS Development NASSCO PACP Certified Phoenix, Arizona Las Vegas, Nevada Nampa, Idaho Salt Lake City, Utah

602-906-1901 702-360-1044 208-466-7190 801-495-4240

www.pecaz.com

Western Society of Trenchless Technology - Trenchless Review - 2009

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Bursting Operation - Steps One & Two

Bursting Operation - Step Three Traffic control was not a major issue during the pipe bursting operation. The city’s traffic operations worked with the contractor, allowing some freedom during non-peak times for better and faster movement. The engineer had a full-time inspector dedicated to the project and the team met weekly to review work completed and the look-ahead schedule.

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STATIC BURSTING WITH VCP Static pipe bursting equipment has been around the industry for many years. Over time the equipment has evolved from a cablepulled bursting head to a more sophisticated system that uses a system of interlocked rods to pull the bursting head. The rigid rods do not stretch under heavy

pulling as a cable would. This becomes particularly crucial when bursting with sectional pipes such as No-Dig VCP. Mission Clay Products first introduced No-Dig vitrified clay jacking pipe in 1992. Vitrified clay pipe is manufactured from 100% natural materials, a blend of clays, shales and slate. No-Dig

Western Society of Trenchless Technology - Trenchless Review - 2009

called a squeezer, with pressure plate keep the assembled pipe sections under compression so the joints remain tight. Equipment included the world’s highest capacity static bursting machine, the Grundoburst 2500G from TT Technologies. This machine is capable of pulling up to 315 tons. It would prove necessary to use virtually all of the machine’s capacity in the difficult soil conditions encountered on the project.

Existing pipe off-center in original 1 m (3 ft) excavation vitrified clay jacking pipe has been the predominant jacking pipe material used in the 8-inch thru 36-inch size range due to its high compressive strength (18,000 psi average), low-profile zero-leakage joint, affordability in the typical 1 or 2 meter pipe lengths, and elimination of an external casing pipe. For this particular project in Phoenix, the bursting equipment was designed and assembled for

the specific purpose of bursting the existing VCP and towing in the new, non-restrained joint VCP. Because the pipe sections are pushed together with restraint, the bursting system was designed to push each pipe joint home and keep the column of assembled pipe sections in compression during bursting. As the bursting head is pulled forward, fracturing the existing VCP and expanding the fragments into the backfill, the rear cylinder pack,

GrundoburstR 2500G and extraction cage in receiving pit

ON THE JOB Project Engineering Consultants (PEC) of Phoenix was one of eight engineering firms selected for this program. PEC worked closely with utility contractor Kiewit Western, Omaha, Neb, to develop an innovative approach to increase the capacity deficiencies with minimal socio-economic impact. The pipe handling, assembly and bursting plan worked very well when put into operation. The project superintendent spent the first couple of bursts working in the excavations with the crew, ensuring he fully understood what was needed and how to pass proper meaningful instructions onto the crew as the project progressed. Launch and receiving pits were located in areas where existing manholes were to be replaced. The manholes were located at approximately 400-foot intervals. The pits were adequately shored with trench boxes to stabilize the walls of the pit. This provided a safe environment for workers and ample room for equipment and pipe. The bursting equipment

Western Society of Trenchless Technology - Trenchless Review - 2009

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the static pipe bursting machine. Cycle times for each section of pipe to be assembled and pulled forward during bursting began at an average rate of 1 foot per minute. As the project progressed, the crew became much more efficient resulting in average rate of 24 inch OD expander followed by new 18 inch VCP 2 feet per minute. jacking pipe on arrival into the receiver Thus, a typical 350 linear foot reach was completed in 2 could easily be rotated 180 to 3 hours or so. degrees in the launching pit and begin bursting pipe from the PROJECT REVIEW opposite direction. Generally, the pipe bursting went smoothly considering the The Grundoburst 2500G conditions that had to be overmachine utilizes Quicklock rods. come. Some of the most chalThe rods were connected to a spelenging conditions and short seccial expander for 18-inch VCP tions had to be hand laid. (22.14-inch O.D.) The expander Without the additional soils O.D. was 24 inches. The information in the trench zone, expander had a special internal the operation ran into an area socket arrangement for the lead where the pipe was capped by piece of VCP to butt against. As slurry. It appeared to be low sections of pipe were installed strength because the bursting additional Quicklock rods were operation pulled through much of added to the trail end of the it. But, in a couple of instances, expander and then the new pipe the head could not burst through section was slipped over the rods. and the operation switched to open cut until they passed the First, the cylinder pack (squeezarea with slurry. The pipe burster) with pressure plate was ing was then restarted again. pinned to the rods. Then it was hydraulically energized to push It was the most economical the pipe joint fully home and choice for the contractor to be then it would hold the assemble able to pipe burst and avoid open pipe sections in compression as cut because they could obtain the pipe bursting expander was much higher production with pulled forward by the 2500G. The pipe bursting. When they would cylinder pack provided 40 tons of come upon these conditions, force to keep the assembled pipe pressures exceeded the limits of segments in compression as the the machine and it was mutually bursting head was pulled toward decided to open cut those por-

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tions. Based just upon the cost differential between conventional open cut and pipe bursting, pipe bursting wins handily. This amounted to $2.6 million or over 30% savings to the City of Phoenix. The contractor opted for open cut over pipe bursting in a few locations; however in some instances, where open-cut was called for, they chose pipe bursting. Pipe production via pipe bursting exceeded everyone’s expectations. However, in some instances, where unknown concrete caps or harder soil conditions were encountered, production using pipe bursting slowed and eventually resulted in an open cut excavation. For the most part, the static push-pull segmented pipe bursting technology using No-Dig VCP proved to be very successful.

Western Society of Trenchless Technology - Trenchless Review - 2009

350 kN (40 ton) Cylinder Pack

index to advertisers INDex To ADverTIsers Akkerman Inc.

20

AP/M Permaform

51

AUI Inc.

35

Bennett Trenchless Engineers

10

DCM Geo Engineers

30

Dudek Engineering

37

Fibrwrap Construction Inc.

4

Geolyn Pipe Inspection Services Ltd.

21

Harris & Associates.

32

Melfred Borzall Inc.

3

Michels Corporation.

6

Pierson Construction Corporation

39

PipeMedic by QuakeWrap

IFC

Pro-Pipe Professional Pipe Services

21

Project Engineering Consultants Ltd.

59

The Robbins Company

42

RS Technical Services, Inc.

44

Sanexen Aqua Pipe

OBC

Sprayroq Inc.

26

SSC (Specialized Services Co.)

7

Trenchless Resources International

8

TT Technologies

53

Vadnais Corporation

9

Veolia ES Sewer Services, Inc.

15

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