Fishbeck, Thompson, Carr & Huber, Inc.
Engineering Designs/Pipe Rehabilitation
September 17, 2013
Agenda Issues Sewer Televising Types of Rehabilitation Available Pros/Cons
Issues Facing Us Today H2S on Rise – “Green Technology” Age of Sewers Changing Regulations Increasing Costs of Open Cut Decreasing Revenue
Condition Assessment
Step #1 – Clean and televise your sewers See what problems you are facing Utilize a contractor that is PACP certified Condition assessment will determine what type of rehab will work best
PACP
Pipeline Assessment and Certification Program Industry standardization of defects MDEQ adopting coding General Pipe Condition Grades (1-5)
Camera Options
Panoramo Cameras on front and rear Captures still images Pictures “stitched” together Televise faster than standard CCTV Viewer can pan/tilt to look at defects Great for structural assessment Large data file
Camera Options
Pan and tilt Standard CCTV Preferred camera for inflow/infiltration (I/I)
Examples of Defects
Multiple fractures Surface spalling Grade 3
Examples of Defects
Hole with voids visible Grade 4
Examples of Defects
Infiltration
Examples of Defects
Broken Grade 5
Examples of Defects
Defective tap
Rehabilitation Methods
Step #2 – Select the type of rehab that best fits your need
Open Cut
Rehabilitation by replacement
Pros Brand new materials Tight system
Open Cut Cons More costly in urban setting More area disturbed Utility/homeowner coordination Longer to construct
Spot Repairs
Open cut point repair Often used in conjunction with CIPP Repair collapsed or badly damaged section of pipe prior to lining or another type of rehab
Spot Repairs
Spot Repairs
Spot Repairs
Cured-in-Place Pipe CIPP is one of the most common methods utilized in Michigan Line from 4 inches to 120 inches Rehab sanitary, storm, water, and pressure pipe Rehab non-circular configurations such as ovals, boxes, bends, and transitional diameters without digging Eliminates inflow and infiltration
Cured-in-Place Pipe
Cured-in-Place Pipe
CIPP lining is not an option: Existing pipe has severe pipe deflection Collapsed pipe, unless a point repair is performed Increase existing pipe capacity
Cured-in-Place Pipe
Liners are typically non-woven polyester felt or fiber reinforced fabric Forms a close fit within the host pipe Designed to sustain loads from groundwater, internal pressure, and soil and traffic Liners saturated with resin Resin includes chemical catalyst to facilitate curing The liner may be chilled for transportation to maintain stability until installed
Cured-in-Place Pipe
Installation methods: Direct inversion Pulled-in-place Direct inversion – turn liner inside out, liner inverts upon itself through the pipe with air or water pressure
Cured-in-Place Pipe
Cured-in-Place Pipe Pulled-in-place – run cable through existing pipe and attach to tube. Carefully pull into place. A hose inverted into the center of the tube inflates the resinsaturated tube with water and holds it tight to the existing pipe. Pulled-in-place preferred method where placement challenges exist.
Cured-in-Place Pipe
CIPP cured by one of three methods: Circulating hot water Steam UV light Hot water most common method UV requires special resins and photo-sensitive initiators Once installed, cured, and cooled, laterals can be reinstated
Cured-in-Place Pipe
Direct water inversion with hot water curing
Cured-in-Place Pipe
Steam curing
Cured-in-Place Pipe Pros Less expensive alternative to open cut Renews pipe for another 50+ years Project can be completed in days versus months Cons If not properly grouted and sealed, lined pipe can still have I/I issues Bypass pump or divert flow
Lateral Lining
Heavy groundwater? Lateral connections to the mainline a big source of infiltration Line laterals at the connection up to the right-of-way or to a cleanout If not lining mainline, use a product such as a T-liner that is manufactured by LMK Technologies which seals the connection and is installed up to a cleanout If lining mainline, there is a CIPP liner that has the lateral liner connected to the mainline liner
Lateral Lining
T-liner
Spot Lining
When a pipe is evaluated, it may be determined that only a few areas are in need of repair or rehabilitation More economical to just repair the identified areas Sectional liner that ranges from 3 feet long to length of repair
Spot Lining
Slip Lining Insert a new pipe of a smaller diameter into a larger, existing pipe HDPE or PVC most commonly used New pipe laid out above ground and pulled through access pit into the host pipe After installation, annular space between new pipe and host pipe grouted Reinstatement of laterals require external point excavations
Slip Lining
Segmental slip lining typically used for larger diameter pipes (Hobas Pipe) Segmental liners can be pushed into the host pipe by hydraulic power or winched into place
Slip Lining Pros Less expensive alternative to open cut New pipe Project can be completed in shorter time than open cut
Cons Still need point excavations Grout selection important to ensure proper loading on liner Downsize pipe diameter
Slip Lining
Project Example City of Lansing, Grand Avenue in Downtown
Slip Lining
Pipe Bursting
Pipe bursting replaces existing pipes in same alignment without physically removing existing pipes Static or pneumatic bursting head bursts the existing pipe and replaces with HDPE, Fusible PVC, composite, clay, and ductile iron HDPE pipe most common Bursting can upsize, such as an 8-inch pipe to a 10or 12-inch Reinstatement of laterals require external point excavations
Pipe Bursting
Pipe Bursting Pros New pipe Can upsize pipe Cons Still need point excavations Should not be utilized when close to structure or other utilities Utilizes same alignment – check to see if existing pipe has backfall or sags Cannot burst through casings
Grouting Primarily used to seal leaks in pipe and laterals Grout fills the void around the pipe where water is entering Pros Seals leaks Good fix with proper material selection Cons Not a structural repair Not a permanent solution Leaks will travel
Spin Casting
Spin caster placed in center of pipe and concrete is centrifugally cast evenly around interior of pipe to predetermined thickness Provides waterproofing, sealing, and corrosion protection for sanitary sewer and storm culverts 30 to 120 inches in diameter Can be applied to concrete, clay, metal, and brick culverts Cures in hours so pipe can be returned to service
Spin Casting Pros Lower cost Cons Requires thorough preparation Bypass pumping required Only used for certain pipe conditions Longer curing time
Fold and Form Lining
Utilizes modified PVC or HDPE that has been folded into a “U” shape Similar installation to pulled-in-place CIPP liners Uses steam heat to reshape to existing pipe once pulled into place Used when existing host pipe can provide structural support No adhesion between liner and host pipe
Fold and Form Lining
Laterals reinstated by remote cutting, sometimes point excavation
Pros Low-cost rehab method Cons Not structural If sewer has hot flows upstream of liner, liner can deform or collapse
Spiral Wound Liners
Liner installed through manhole or insertion pit Liner strips of PVC, steel reinforced PVC, or HDPE Installed from winding machine
Spiral Wound Liners
Liner forms water-tight liner In smaller diameter pipes, liner can be expanded to fit tight to host pipe Or, liner installed to fixed dimension and annular space grouted Laterals reinstated after lining Grouting done to lock liner in place and transfer load from host pipe
Spiral Wound Liners Pros Structural pipe renewal Lower cost Cons Only used for gravity sewers
Conclusion Many types of rehabilitation available CIPP one of better options for H2S Gas Issues Common vs. Specialty Research Find best fit for your needs
Fishbeck, Thompson, Carr & Huber, Inc.
Questions? Contact Info: Deann Falkowski
[email protected] (517) 887-4009
