T-Wall Design Procedure FLAC to Procedure
by by
Neil Schwanz, P.E. and Kent Hokens, P.E. April April 8, 8, 2008 2008
Purpose Provide Overview of How T -wall Design T-wall Procedure Was Developed so Designers Understand its Basis and Limitations
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Outline • FLAC Overview • GeoMatrix numercial analyses and report • Product Delivery Team (PDT) analyses • FLAC to Design Procedure
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Soil Structure Interaction and Load Transfer Mechanism of Pile Supported T -Walls T-Walls in New Orleans, LA Michael Navin, Ph.D., P.E. St. Louis District 2007 Infrastructure Conference th 2007 June 28th
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FLAC (Fast Lagrangian Analysis of Continua) Two -dimensional continuum code for modeling soil, Two-dimensional rock and structural behavior. • General Program – model together soil, structure,
pressures, etc. to evaluate deformation, loads stresses • Linear or Non -linear soil models Non-linear •• ••
Mohr -Coulomb (bilinear: Mohr-Coulomb (bilinear: linear linear elastic elastic perfectly perfectly plastic plastic LEPP) LEPP) Fully -linear Fully non non-linear
• Soil Structure Interaction • Factor of Safety (c -phi reduction technique) (c-phi 08 April 2008
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T -Wall Product Delivery Team (PDT) T-Wall New Orleans District
Headquarters •• ••
Anjana Anjana Chudgar Chudgar,, P.E. P.E. Don Don Dressler, Dressler, P.E. P.E.
•• •• ••
Reed Reed Mosher, Mosher, Ph.D. Ph.D. Noah Noah Vroman Vroman,, P.E. P.E. Ronald Ronald Wahl Wahl Don Don Yule, Yule, P.E. P.E.
GeoMatrix •• •• ••
• •
ERDC ••
•
• •
Mississippi Valley Division • •
C. C. Y. Y. Chang Chang Faiz Faiz Makdisi Makdisi,, Ph.D Ph.D,, P.E. P.E. Z. Z. L. L. Wang Wang
Charles Brandstetter, P.E. Thomas Hassenboehler, P.E. Richard Pinner, P.E. Mark Woodward, P.E. OTHERS
• •
Allen Perry, P.E. Kent Hokens, P.E. Michael Navin, Ph.D., P.E. Neil Schwanz, P.E.
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Example used in GMX FLAC analysis
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Soil Stratigraphy of GMX FLAC analysis 0’
-50’
Elevation
-25’
-75’ -100’ -125’ -150’
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GMX mesh around the T-Wall 10’ 5’ Elevation
0
-5’ -10’
-15’ 08 April 2008
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FLAC and numerical stress -strain analyses stress-strain Increasingly used to evaluate embankment stability –– same same FS FS as as limit equilibrium methods ’s Procedure. methods like like Spencer Spencer’s Valuable for complex or unusual site conditions. Piles included -y and -z springs. included as as structural structural elements elements with with p p-y and tt-z springs.
Piles connected to mesh with springs.
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GeoMatrix used the FLAC model to perform sensitivity analyses. Mohr -Coulomb vs. -linear soil models Mohr-Coulomb vs. fully non non-linear Soil Soil modulus modulus values values •• Shear Shear modulus modulus ratio ratio based based on on pressuremeter pressuremeter tests tests •• Shear Shear modulus modulus ratio ratio based based on on triaxial triaxial tests tests
Pile –– soil soil spring spring stiffness stiffness Water load on T -Wall vs. T-Wall vs. load load on on ground ground surface surface With With and and without without sheet sheet pile pile Soil Soil strength strength reduction reduction
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The two stage loading in GMX report revealed most deflections due to water load on the ground surface.
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Displacement vectors (ft) max vector = 2.173E-01 0
Displacements
5E -1 0.100
-0.100
-0.500
Elevation (ft) (* 102)
-0.300
-0.700
-0.900
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Displacements
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Axial Loads (lbs) Axial Force on Structure Max. Value
0.100
Left Pile
-0.100
Middle Pile
-0.500
Elevation (ft) (* 102)
-0.300
-0.700
Right Pile
-0.900
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Shear in Pile Shear Force (lbs) on Structure Max. Value 0.100
Left Pile
-0.100
Middle Pile
-0.500
Elevation (ft) (* 102)
-0.300
-0.700
Right Pile
-0.900
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Moment (lb-ft) on Structure Max. Value
Moment in Pile 0.100
Left Pile
-0.100
Middle Pile
-0.500
Elevation (ft) (* 102)
-0.300
-0.700
Right Pile
-0.900
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Without Sheet Pile Right Pile
Middle Pile
Left Pile
-20
-20
-20
-40
-40
-40
Elevation (ft)
0
Elevation (ft)
0
Elevation (ft)
0
without sheet pile with sheet pile with hydraulic fracturing
-60
-60
-60
-80
-80
-80
-100
-100
-100
-40000
0
40000 80000
Axial Force of Piles (lbs)
-40000
0
40000 80000
Axial Force of Piles (lbs)
-40000
0
40000 80000
Axial Force of Piles (lbs)
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Investigations by Product Delivery Team FLAC 2D – using the GMX model Plaxis 2D and 3D UTexas4 Group 7 CPGA LPile and T -Z pile T-Z
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Investigations with FLAC GMX model 20 20’’ water load on wall Short piles Vertical piles Applied unbalanced load Strength reduction factor (SRF)
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Vertical piles How How does does batter batter affect affect pile pile response? response?
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Applied unbalanced load • Load distributed along left H-Pile above critical • • •
failure surface. Load distributed along all piles above critical failure surface. Load distributed along full length of all piles. Load applied at structure.
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Strength reduction factor (SRF) FLAC for slope stability •• Performs Performs an an automated automated strength strength reduction reduction routine routine •• Matches Matches FS FS from from limit limit equilibrium equilibrium analysis analysis
(UTexas4, (UTexas4, Slide, Slide, SlopeW SlopeW))
Questions about T -wall example T-wall •• Is Is the the wall wall still still stable stable with with lower lower soil soil strengths? strengths? •• How How does does SRF SRF compare compare to to design design method? method? •• How How does does presence presence of of piles piles change change failure failure mechanism? mechanism?
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Strength reduction factors (SRF = 2.75)
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Strength reduction factors (SRF) 4
SRF
3
Elastic
PMT G/Su
Plastic
2 Triaxial G/Su
1 0 0.0
0.1
0.2
0.3
0.4
0.5
0.6
Horizontal Displacement (ft) 08 April 2008
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FLAC Analysis Conclusions Presence of sheet pile did not affect pile loads or deflections Battered H -pile much more effective than H-pile vertical H -Piles and T -Wall are Effective in Stabilizing H-Piles T-Wall the Soil Mass
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Investigations with Plaxis 3D • Flow of soil between piles • Allowable pile spacing • Load distribution between pile rows
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3 -D Plaxis Model Displacements 3-D
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Summary -Walls are a complex SSI problem • T T-Walls • Numerical analyses illustrate SSI
behavior • Outside sources willing to supply FLAC model add great value to the report • Goal is to determine practical methodology
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Method Development Provide Overview of How T -wall Design T-wall Procedure Was Developed so Designers Understand its Basis and Limitations
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Design Method Development PDT as shown in early slide Use existing tools and methods if possible Replicate FLAC Results Reasonable Design
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Methods Various Methods Tried – Reinforced Slope Concept FLAC Models with Applied Lateral Load Tried Applying Lateral Loads in Ensoft Group 7 • At Rest Pressure • Unbalanced Load
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Moment (lb-ft) on Structure Max. Value
Moment in Pile 0.100
Left Pile
-0.100
Middle Pile
-0.500
Elevation (ft) (* 102)
-0.300
-0.700
Right Pile
-0.900
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Shear in Pile Shear Force (lbs) on Structure Max. Value 0.100
Left Pile
-0.100
Middle Pile
-0.500
Elevation (ft) (* 102)
-0.300
-0.700
Right Pile
-0.900
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Design Method Group 7 Method • Compute ““Unbalanced” Unbalanced” Load to Provide Factor of Safety • Apply Unbalanced Force Directly to Piles • No lateral soil resistance to critical failure surface • ““Normal” Normal” Loads on Wall itself • Matched FLAC results. • Pile Forces Computed Directly
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Method Development Directly Second FLAC model (18 (18’’ Water Elevation) also had good correlation with Group 7 Method Pile Distribution (50% on Lead Pile) selected from FLAC results – axial loads not sensitive to this CPGA approximation developed to help deal with the many load cases
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CPGA Approximation
Fcap
⎡ ⎛ Lp ⎞⎤ ⎢ ⎜⎜ + R ⎟⎟ ⎥ L 2 ⎝ ⎠⎥ p ⎢ = Fub ⎢ (L p + R ) ⎥ Lu ⎢ ⎥ ⎣ ⎦
R=4
EI Es
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Comparison, Axial Loads Deflection
Axial Loading in Piles (kips)
(in)
Left
Middle
Right
Group 7, Pervious
0.52
-39.7
91.8
3.6
Group 7, Impervious
0.49
-35.4
89.6
10.7
CPGA, Pervious
0.46
-45.0
100.4
0.6
CPGA, Impervious
0.43
-41.0
97.9
7.8
FLAC
2.21
-32.5
95.7
6.7
Ex 1, Group 7, Pervious
0.53
-39.9
93.5
2.3
Ex 1, Group 7, Impervious
0.49
-35.8
91.5
9.2
Ex 1, CPGA, Pervious
0.66
-46.8
97.2
5.2
Ex 1, CPGA, Impervious
0.61
-42.3
94.4
12.5
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Comparison, Moments Max + Moment (kip-ft
Max - Moment (kip-ft
%
Left
Middle
Right
Left
Middle
Right
Group 7, Pervious
50
23.9
8.75
7.47
-20.6
-17.5
-19.7
Group 7, Impervious
50
24.3
9.17
7.98
-19.8
-16.5
-18.5
41.5
28.5
21.6
-15.2
-10.8
-10.8
FLAC Ex 1, Group 7, Pervious
50
26.2
9.5
8.2
-21.5
-17.3
-18.9
Ex 1, Group 7, Impervious
50
26.5
9.9
8.6
-20.8
-16.5
-18.1
Ex 1, Group 7, Pervious
100
69.8
-
-
-36.8
-17.2
-19.1
Ex 1, Group 7, Impervious
100
70.3
-
-
-36.3
-16.1
-18.0
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Flow Through Direct Transfer of Soil Movement to Piles Ensure Piles Really Take All Load Limited 3D model studies Research – studies of lateral soil loading on piles piles and and pile Groups has been studied numerous times Method developed from these studies.
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Flow Through Check Flow Through, Type 1 Pile Lateral Capacity Basic Capacity Pult ult = 9Cu
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Question?
Thank You 08 April 2008
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Comparison Between Spencer’s Method And Method of Planes by by
Rich Varuso, P.E. April April 8, 8, 2008 2008
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Method of Planes Analysis (MOP) Useful in Lower Mississippi River Alluvial Valley for: •
Highly stratified soft soils
•
Moderately weak soils on a hard surface
•
Or in a foundation with one or more weak zones
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Method of Planes Divides soil mass into three segments • Active wedge • Central block • Passive wedge
Wedges are treated as rigid bodies (according to Coulomb)
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Method of Planes A
C
Assumed failure surface (Plane ABEF)
Wa
Shear strength of soil: τ = c + σ tanφ
D
cL
F
φ Wp Wb
cL
Ua φ Up
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α2
α1
E
cL
B
φ Ub
Note: α1 and α2 usually assumed equal to 45°+φ/2 and 45°-φ/2; respectively.
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49
Method of Planes FS =
Ra + R b + R p Da - Dp
Da = Ra = Rb = Dp = Rp = FW=
Active Driving Force Active Resistance Central Block Resistance Passive Driving Resistance Passive Resistance Lateral Free Water Pressure
UL = (Da – FW) – (Ra + Rb + Rp + Dp ) 08 April 2008
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Spencer ’s Method Spencer’s HSDRRSDG Table 3.1: ““Spencer Spencer method shall be used for circular and non -circular failure non-circular surfaces since it satisfies all conditions of static equilibrium and because its numerical stability is well suited for computer application. ” application.” Finding the shear -normal ratio that makes the shear-normal two factors of safety equal, means that both moment and force equilibrium are satisfied. 08 April 2008
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Spencer ’s Method Spencer’s Spencer (1967) developed two factor of safety equations; one with respect to moment equilibrium and another with respect to horizontal force equilibrium. He adopted a constant relationship between the interslice shear and normal forces, and through an iterative procedure altered the interslice shear to normal ratio until the two factors of safety were the same. Finding -normal ratio Finding the the shear shear-normal ratio that that makes makes the the two two factors factors of of safety equal, means that both moment and and force equilibrium are satisfied. 08 April 2008
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Spencer ’s Method Spencer’s
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Spencer ’s Method Spencer’s
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Spencer ’s Method Spencer’s Determine -circular failure surface: Determine the the non non-circular Sufficient analysis has been done to varying soil profiles to assure that the non -circular surfaces non-circular shall govern the stability assessment. Numerical modeling has indicated that soil displacement is nearly horizontal under the base of a pile -supported T -Wall. pile-supported T-Wall.
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Spencer ’s Method Spencer’s Unrealistic Slip Surface
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Spencer ’s Method Spencer’s EM -2-1902 requires EM 1110 1110-2-1902 requires verification verification of of the the results results of of computer computer analysis: ““All All reports, reports, except except reconnaissance reconnaissance phase phase reports, reports, that that deal deal with with critical critical embankments embankments or or slopes slopes should should include include verification verification of of the the results results of of computer computer analyses. analyses. The The verification verification should should be be commensurate commensurate with with the the level level of of risk risk associated associated with with the the structure structure and and should should include include one one or or more more of of the the following following methods methods of of analysis analysis using: using: (1) (1) Graphical Graphical (force (force polygon) polygon) method. method. (2) (2) Spreadsheet Spreadsheet calculations. calculations. (3) (3) Another Another slope slope stability stability computer computer program. program. (4) ” (4) Slope Slope stability stability charts. charts.”
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Spencer ’s Method Spencer’s Slope Stability Design Factors of Safety for T -Walls T-Walls
Analysis Condition
Required Minimum Factor of Safety Spencer’s Method
MOP
Protected Side (SWL)
1.5
1.3
Protected Side (top of wall - TOW)
1.4
1.3
Floodside (low water)
1.4
1.3
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Spencer ’s Method Spencer’s Stability Analysis using Method of Planes (MOP) HSDRRSDG: ““LMVD LMVD Method of Planes shall be used as a design check for verification that the HPS design satisfies historic district requirements. Analysis shall include a full search for the critical failure surface since it may vary from that found following ’s Method. ” following the the Spencer Spencer’s Method.”
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Spencer ’s Method Spencer’s Spencer ’s Method compared to MOP Spencer’s
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Question?
Thank You 08 April 2008
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T-Wall Design Procedure for Unbalanced Load
by by
Mark Gonski, P.E., Kent Hokens, P.E., Neil Schwanz, P.E., Rob Werner and Brian Powell April April 8, 8, 2008 2008 One Team: Relevant, Ready, Responsive and Reliable
NEW METHODOLOGY STEP 1
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NEW METHODOLOGY STEP 1a
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NEW METHODOLOGY STEPS 2 & 3
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NEW METHODOLOGY STEPS 4 & 5
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NEW METHODOLOGY STEPS 6 & 7
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NEW METHODOLOGY NOTES
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Purpose Step by Step Design Method Example No. 1 with SWL = El. +10 ft (target FS = 1.5)
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Steps Overview 1. Check Factor of Safety •• •• ••
2. 3. 4. 5. 6. 7.
UTexas4 UTexas4 Spencer Spencer Search Search Methodology Methodology UT4 UT4 Results Results for for Example Example 11 Slope/W Slope/W Methodology Methodology and and Results Results for for Example Example 11
Find Unbalanced Load Compute Pile Capacities Preliminary Design with CPGA – check flow through Group 7 Analysis of critical cases Find Reinforcement Forces Check Global FOS with Reinforcement
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UTexas4 Search Methodology 1. Problem Definition – Program Input 2. Trial Failure Surfaces 3. 4.
Solution Convergence Automatic Searches
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UTexas4 – Program Input 1. UTexas4 vs. Earlier Versions 1. 1. Property Property Interpolation Interpolation 2. 2. Weight Weight of of Free Free Water Water
2. T -Wall Design Input T-Wall 1. 1. Soil Soil Layers Layers and and Properties Properties 2. 2. Piezometric Piezometric Surface Surface & & Water Water Load Load (Unit (Unit Weight Weight H2O) H2O) 3. 3. Weight Weight of of Wall Wall & & Forces Forces on on Wall Wall
3. Analysis/Computation 1. 1. Procedure Procedure (Spencer (Spencer == Default) Default) 2. 2. Trial Trial Surface Surface & & Automatic Automatic Search Search Criteria Criteria
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UTexas4 – Trial Surfaces 1. Circular Surface 1. 1. Initial Initial Trial Trial Center Center & & Radius Radius 2. 2. Tangent Tangent,, Radius Radius & & Point Point Modes Modes Stop” Command 3. 3. ““Stop” Command
2. Non -Circular Surface Non-Circular -Point ““Wedge” Wedge” Surface 1. 1. Initial Initial 44-Point Surface (MOP (MOP == Guide) Guide) -Point) 2. 2. 0.7H 0.7H Base Base Length Length Constraint Constraint (the (the 5th 5th-Point)
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UTexas4 - Solution Convergence 1. A Unique Solution ? 2. Convergence Criteria 1. 1. Force Force Imbalance Imbalance 2. 2. Moment Moment Imbalance Imbalance
3. What to Look For 1. 1. Cautions Cautions and and Warnings Warnings 2. 2. Sense Sense of of Inclination Inclination 3. 3. Number Number of of Iterations Iterations and and Convergence Convergence Trends Trends
4. Troubleshooting Suggestions 1. 1. 2. 2. 3. 3.
Work Work Near Near Origin Origin (Moments (Moments are are taken taken about about 0,0) 0,0) Trial Trial FS FS >> Expected Expected FS FS (Default (Default is is 3.0) 3.0) Reduce Reduce Trial Trial Inclination Inclination (Default (Default is is 15 15 degrees) degrees)
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UTexas4 - Automatic Searches 1. 2. 3.
Local vs. Global Min. FS Local vs. Global Max. Unbalanced Load Circular Search 1. 1. Floating Floating and and Fixed Fixed Grid Grid
4. Non -Circular Search Non-Circular 1. 1. 2. 2. 3. 3.
Degree Degree of of Freedom Freedom (No. (No. of of Points Points and and Shift Shift Direction) Direction) Shift Shift Distance Distance Coarse Coarse to to Fine Fine -- Recycling Recycling and and Refining Refining Output Output as as Input Input
5. Results Non -Circular Typically Non-Circular Typically More More Critical Critical than than Circular Circular FS FS Usually Usually Decreases Decreases as as No. No. Points Points Increases Increases and and Shift Shift Distance Distance Decreases Decreases -Stage) 3. 3. Several Several Successive Successive Runs Runs are are Required Required (Single (Single-Stage) 1. 1. 2. 2.
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Steps 1 and 2 - UT4 Results 1. Spencer Procedure Model (UTexas4 or 2. 3. 4.
Slope/W) Starting wall configuration Establish stratigraphy and soil properties Find failure surfaces that correspond to Lowest FS and Highest Unbalanced Load by evaluating several tangent elevations
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CH CH CH CH
ML
CH
CH 08 April 2008
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Step 1 (tangent elev. at --8 8 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -8 ft
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Step 2.1 Search for highest unbalanced load Surface Defined as non -circular non-circular Min of 0.7 H or Base Width Force located half way from ground surface at heel to elevation of critical failure surface Two cases SWL and TOW (only SWL shown)
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
600 lbs/ft
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Step 1 (tangent elev. at --14 14 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -14 ft
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
2500 lbs/ft
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Step 1 (tangent elev. at --18 18 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -18 ft
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
3800 lbs/ft
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Step 1 (tangent elev. at --22.9 22.9 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -22.9 ft
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
5350 lbs/ft
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Step 1 (tangent elev. at --23.1 23.1 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -23.1 ft
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
650 lbs/ft
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Step 1 (tangent elev. at --26 26 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -26 ft
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
1250 lbs/ft
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Step 1 (tangent elev. at --30 30 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -30 ft
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
1450 lbs/ft
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Step 1 (tangent elev. at --39 39 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -39 ft
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Step 1 (tangent elev. at --43.5 43.5 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -43.5 ft
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Step 1 (tangent elev. at --50 50 ft) Check Global FOS using Spencer ’s Method Spencer’s
El. -50 ft
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Step 2.2 Summary of Results Neutral Block Tangent EL (ft)
Factor of Safety
Unbalanced Load (lbs/ft)
-8
1.32
600
-14
1.10
2500
-18
1.03
3800
-22.9
0.98
5350
-23.1
1.44
650
-26
1.40
1250
-30
1.40
1450
-39
1.67
-
-43.5
2.08
-
-50
2.31
-
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97
Step 2.2 Check Failure Surfaces with MOP
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Step 2.2 Check Failure Surfaces with MOP
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Steps 1 & 2 Spencer ’s Analysis Spencer’s Spencer ’s Procedure for T -Walls using Spencer’s T-Walls Slope/W
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100
SLOPE/W Spencer ’s Analysis Spencer’s Slope/W Problem Setup
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SLOPE/W Spencer ’s Analysis Spencer’s Slope/W Problem Setup
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SLOPE/W Spencer ’s Analysis Spencer’s Slope/W Problem Setup
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SLOPE/W Spencer ’s Analysis Spencer’s Do not cross block slip surface lines
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SLOPE/W Spencer ’s Analysis Spencer’s Create Profile – Paste MOP StabCheck.xls
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SLOPE/W Spencer ’s Analysis Spencer’s Material Property Models
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SLOPE/W Spencer ’s Analysis Spencer’s Spatial Mohr -Coulomb - Cohesion Mohr-Coulomb
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SLOPE/W Spencer ’s Analysis Spencer’s Example #1
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SLOPE/W Spencer ’s Analysis Spencer’s Example #1 – Cohesion Contours
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Step 1 Block Specified
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Step 1 Critical Factor of Safety @ EL. --23 23
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Step 1 Factor of Safety Contours (Safety Map, Increment =0.1) FS = 1.1
FS = 1.5
FS = 1.4
FS = 1.2
FS = 1.3
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Step 1 (tangent elev. at --8 8 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --14 14 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --18 18 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --23 23 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --23.1 23.1 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --26.1 26.1 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --31 31 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.1 Compute Stabilizing Force to Achieve Target FOS
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Step 1 (tangent elev. at --39 39 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 1 (tangent elev. at --43.5 43.5 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 1 (tangent elev. at --50 50 ft) Check Global FOS using Spencer ’s Method Spencer’s
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Step 2.2 Summary of Results Neutral Block Tangent EL (ft)
Factor of Safety
Unbalanced Load (lbs/ft)
-8
1.26
900
-14
1.09
2550
-18
1.03
3950
-23
0.98
5500
-23.1
1.42
800
-26.1
1.42
1150
-31
1.42
1200
-39
1.64
-
-43.5
2.03
-
-50
2.38
-
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130
3.1 – Axial Capacity Compute axial capacity according to 3.3 of the HSDRS – based on EM 1110 -2-2906 – None Above Failure 1110-2-2906 Surface Capacity (Tons) 70
Compression
80
90
100
110
120
130
140
-92 74 Tons -93
Pile test at tip EL -92.5
-94
Trial Trial Pile Pile Tip Tip El 92.5 El --92.5
-95
Capacity Capacity FS FS =2 =2
EL (ft)
-96 -97 -98
74 74 ton ton ** 22 t/k t/k /2 /2 == 74 74 kips kips
2 Tons/ft
Interpretation considering blow counts and 40% of pile tip block area for end bearing 85 Tons
100 Tons
-99 10 Tons/ft -100 -101
129.75 Tons Pile test at tip EL -101
-102
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3.1 – Axial Capacity Tension Trial 92.5 Trial Pile Pile Tip Tip El El --92.5 Ultimate Ultimate == 81 81 tons tons Capacity 23 == 77 tons Capacity to to --23 tons Net Net Ultimate Ultimate == 81 81 –– 77 == 74 74 ton ton FS FS == 3.0 3.0 –– theoretical theoretical Cap Cap == 74 74 // 2t/k 2t/k ** 3.0 3.0 == 49 49 kip kip
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3.2 Lateral Capacity Compute a lateral capacity at the elevation of the lowest failure surface with L -pile or L-pile COM624G •• Analyze with the top of the pile as a free head •• Add surcharge as thin layer with high unit weight •• Curve not Bilinear Bilinear – carry to pile yield •• Factors of Safety for Calculated Loads (3.0)
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3.2 Compute Moment Capacity of HP 14x73 Fy Sx = 50 ksi x 107 in3 = 5,350 lb-in = 456 kip–ft
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3.2 Maximum Moment vs. Top Shear 460,000 440,000 420,000 400,000 380,000 360,000
Maximum Moment, -
340,000 320,000 300,000 280,000 260,000 240,000 220,000 200,000 180,000 160,000 140,000 120,000 100,000 80,000 60,000 40,000 20,000 0 0
10,000
20,000
30,000
40,000
Top Shear, LPILE Plus 5.0, (c) 2007 by Ensoft, Inc.
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Step 3 S h e a r F o r c e v s . T o p D e fle c tio n 4 4 ,0 0 0 4 2 ,0 0 0 4 0 ,0 0 0 3 8 ,0 0 0 3 6 ,0 0 0 3 4 ,0 0 0 3 2 ,0 0 0
Shear Force,
3 0 ,0 0 0 2 8 ,0 0 0
26 kips
2 6 ,0 0 0 2 4 ,0 0 0 2 2 ,0 0 0 2 0 ,0 0 0
Allowable Shear =26 kips / (FS=3.0) = 8.7 kips
1 8 ,0 0 0 1 6 ,0 0 0 1 4 ,0 0 0 1 2 ,0 0 0 1 0 ,0 0 0
8.7 kips
8 ,0 0 0 6 ,0 0 0 4 ,0 0 0 2 ,0 0 0 0
0 .5
1
To p D e fle c tio n, L P IL E P l u s 5 .0 , ( c ) 2 0 0 7 b y E n s o ft, In c .
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R=4
EI Es
Step 4 •• Preliminary Layout •• CPGA and compute Equivalent Force in Cap •• Normal Structural Loads above Base, Unbalanced Load
Below Base •• CPGA Approximates Group – – Not Not an an Alternative Alternative to to •• Load Cases as defined in HSDRS Design Criteria •• Check Flow through
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Step 4
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4.1 Calculate Fcap Fcap
⎡ ⎛ Lp ⎞⎤ ⎢ ⎜⎜ + R ⎟⎟ ⎥ L 2 ⎝ ⎠⎥ p ⎢ = Fub ⎢ (L p + R ) ⎥ Lu ⎢ ⎥ ⎣ ⎦
R=
4
EI Es
EI are Pile Properties Es is below failure surface 08 April 2008
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4.1 Example Ground Surface at Unbalance Load Top = -0.5 Equivalent Unbalanced Force for CPGA EL -2
EL -5
Uniform Unbalanced Force, 5,350 lb / ft Lu= 22.4 ft
Lp= 17.9 ft
Silt
EL -22.9 EL -26 R
Clay 1
Critical Failure Surface EL -39
Clay 2
Pile 3
Pile 2
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4.1 R and Fcap Piles HP 14x73. I = 729 in44 E = 29,000 ksi Es for R ((-22.9) -22.9) Average silt and upper clay Es = 100 psi
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R=4
29,000,000 psi × 729in 4 = 120.6in = 10.05 ft 100 psi
4.1 – R and Fcap 29,000,000 psi × 729in 4 = 120.6in = 10 ft R=4 100 psi
Fcap
⎞ ⎛ Lp ⎛ 17.9 ft ⎞ ⎟ ⎜ + 10 ft ⎟ +R L ⎜ p ⎟ ⎟ 17.9 = 2,904lb / ft = 5,350lb / ft × ⎜ 2 = Fub × ⎜ 2 ⎜ LP + R ⎟ Lu ⎜ 17.9 ft + 10 ft ⎟ 22.4 ⎜ ⎟ ⎟ ⎜ ⎝ ⎠ ⎠ ⎝
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4.1 – Calculate Resultants US Army Corps of Engineers
PROJECT TITLE:
COMPUTED BY: DATE:
T-Wall Design Example
KDH
SUBJECT TITLE:
CHECKED BY:
US Army Corps of Engineers
SHEET:
04/05/08 DATE:
Water at El. 10', Pervious
Saint Paul Distict
Input for CPGA pile analysis Upstream Water Elevation Downstream Water Elevation Wall Top Elevation Structure Bottom Elevation Base Width Toe Width Wall Thickness Base Thickness Vertical Forces Component Height Stem Concrete 15 Heel Concrete 2.5 Toe Concrete 2.5 Heel Water 9 Toe Water 1.5 Heel Soil 3.5 -Triangle 1.50 Toe Soil 3.5 Rect Uplift -4 Tri Uplift -11 Sum Vertical Forces
10 -1 12.5 -5 13 1.5 1.5 2.5
x1 10 0 11.5 0 11.5 0 0 11.5 0 0
ft ft ft ft ft ft ft ft
Gamma 0.15 0.15 0.15 0.0625 0.0625 0.110 -0.048 0.110 0.0625 0.0625
Horizontal Forces Component H1 H2 Gamma Lat. Coeff. Driving Water 10 -5 0.0625 1 Resisting Water -1 -5 0.0625 1 Lateraral soil forces assumed equal and negligible Sum Horizontal Forces Total Structural Forces About Heel
1 1 0.0625 0.15 0.110 5.0 0.30 -0.50
Force 3.38 4.31 0.56 5.63 0.14 3.85 -0.18 0.58 -3.25 -4.47 10.5
Arm 10.75 5.75 12.25 5 12.25 5 1.67 12.25 6.5 4.3
Force 7.03 -0.50
Arm 5.00 1.33
Moment 35.16 -0.67
6.53
5.28
34.49
Net Vert. Force 10.55
15
Arm 11.17
ft ft kcf kcf kcf ft ft
Moment 36.3 24.8 6.9 28.1 1.7 19.3 -0.3 7.1 -21.1 -19.4 83.4 ft-k
ft-k
Moment 117.84 ft-k
Net Vertical Arm From Toe 1.83
10
Concrete Water Uplift Soil
-5
SUBJECT TITLE:
CHECKED BY:
Unbalanced Force. Fub Elevation of Critical Surface Length - Ground to Crit. Surface, Lu Length - Base to Crit. Surface, Lp
SHEET:
04/05/08 DATE:
From UTexas Analysis From UTexas Analysis (assume failure surface is normal to pile)
18 ft 4
in 2 lb/in 2 lb/in in lb/ft
HP14x73
1/4
(EI / Es) Fub * (Lp/2 +R) / (Lp +R) (Lp/Lu)
Step 4 CPGA Input PX PY PZ MX MY MZ
-47.19 kips 52.73 kips 0 -96.29 kip-ft 0
Group Input - Steps 5 and 6 3 Pile Rows Parallel to Wall Face Unbalanced Loading on Piles for Group Analysis Fub * Model Width /Lu Total 100 lb/in 50% 50 lb/in For Pile on Protected Sied 25% 25 lb/in Note: Applied to length of pile from bottom of cap to top of critical surface. 18 Step 5 Cap Loads for Group Analysis PX PY PZ MX MY MZ
ft
Moment About Toe -19.3 ft-k Model Width 5 ft
5,350 lb/ft -22.9 ft 22.4 ft
Pile Moment of Inertia. I 729 Pile Modulus of Elasticity E 29,000,000 Soil Modulus of Subgrade Reaction, Es 100 Soil Stiffness Parameter, R 121 Equivalent Unbalanced Force, Fcap 2,906
5
0
KDH
Calculation of Unbalanced Force
Back Fill Soil Elevation Front Fill Soil Elevation Gamma Water Gamma Concrete Gamma Sat. Backfill Distance to Backfill Break Slope of Back Fill Soil Elevation at Heel
x2 11.5 11.5 13 10 13 10 5.0 13 13 13
COMPUTED BY: DATE:
T-Wall Design Example Water at El. 10', Pervious
Saint Paul Distict
Pervious Foundation Assumption
PROJECT TITLE:
52,731 lb 32,656 lb 0 lb 0 0 1,155,441 lb-in
Step 6 Cap Loads for Group Analysis of Unbalanced Load Distance From Base to Ground Surface, Ds 4.50 ft
-10
-15
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-25 0
5
10
15
20
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PX 0 lb PY 5,374 lb PZ 0 lb MX 0 MY 0 MZ Reliable -145,095 lb-in and
Fub * Model Width / Lu * Ds
143 -PZ * Ds/2
Es =
(1.5 − 1.2) (100 psi ) = 40%(100) = 40 psi (1.5 − 1.0)
4.2 - CPGA Es Es = 0 (0.000001) for FS 3.75 Rga = 0.64(saa/b)0.34 aa
Where: saa = spacing between piles perpendicular to the direction of loading (parallel to the wall face). Normally piles should be spaced no closer than 5 feet on center. b = pile diameter or width 08 April 2008
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4.3 – Group Reduction For loading parallel to the loading direction: For leading (flood side) piles: 0.26 ; or = Rgbl = 0.7(sbb/b)0.26 = 1.0 1.0 for for sbb/b > 4.0 4.0
For trailing piles, the reduction factor, Rgbt is: 0.3; or = 1.0 for Rgbt = 0.48(sbb/b)0.3 for sbb/b > 7.0 7.0
Trailing Piles only follow piles with same batter
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4.3 CPGA Analysis LOAD LOAD CASE CASE -PILE F1 PILE F1 KK 11 .0 .0 22 .0 .0 33 .0 .0
11
LOAD LOAD CASE CASE -PILE F1 PILE F1 KK 11 .0 .0 22 .0 .0 33 .0 .0
22
Pervious Pervious Uplift Uplift Assumption Assumption F2 F3 M1 M2 F2 F3 M1 M2 KK KK IN -K IN -K IN-K IN-K .0 5.2 .0 --3.3 3.3 .0 5.2 .0 .0 97.2 .0 --3.0 3.0 .0 97.2 .0 46.8 .0 3.1 .0 --46.8 .0 .0 3.1
M3 ALF M3 ALF IN -K IN-K .0 .0 .07 .07 .0 .0 1.31 1.31 .0 .0 .96 .96
Impervious Impervious Uplift Uplift Assumption Assumption F2 F3 M1 M2 F2 F3 M1 M2 KK KK IN -K IN -K IN-K IN-K 3.0 .0 12.5 .0 --3.0 .0 12.5 .0 .0 94.4 .0 --2.8 2.8 .0 94.4 .0 .0 --42.3 42.3 .0 2.9 .0 .0 2.9
M3 ALF M3 ALF IN -K IN-K .0 .0 .17 .17 .0 .0 1.28 1.28 .0 .0 .86 .86
CBF CBF .02 .02 .31 .31 .15 .15
CBF CBF .04 .04 .30 .30 .14 .14
PILE CAP DISPLACEMENTS LOAD CASE DX DZ R IN IN RAD 1 -.6619E+00 -.2626E+00 -.2868E-02 2 -.6125E+00 -.2266E+00 -.2549E-02 08 April 2008
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4.4 Sheet pile Sheet pile as required for seepage Or Minimum 55’’ Below Critical Failure Surface Minimum Size - PZ --22 22 – No Analysis Example Tip Elevation = --23 23 - 5 = --28 28
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4.5 Flow Through Check 1
Pile Lateral Capacity Basic Capacity Pult ult = 9Cu
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∑ Pall =
n ∑ Pult 1.5
4.5 Flow Through Compute Capacity of Floodside Row
n ∑ Pult ∑ Pall = 1.5 n = number of piles in row per monolith ΣPult = summation of Pult over the height Lp Pult = β(9Sub) Su = soil shear strength b = pile width β = group reduction factor pile spacing parallel to the load (Defined in criteria) 08 April 2008
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4.5 Soils under slab, Suu = 120 psf to failure surface Pile width, b = 14 ” 14” Group reduction factor, not applicable (single row on flood side), Rf = 1
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⎛ ⎞ ⎜ ⎟ in 14 ⎟ = 1,260lb / ft Pult = 1.0(9)(120 psf )⎜ ⎜ in ⎟ 12 ⎟ ⎜ One Team: Relevant,⎝Ready, ft Responsive and Reliable ⎠
153
4.5 Capacity of Floodside Floodside Rows ΣΣP Pult = summation summation of of Pult ult ult over the height Lpp, ΣPult = 1,260 lb/ft(17.9 ft) = 22,554 lb ∑ Pall =
n ∑ Pult 1.5
ΣPall = 1(22,554lb) /1.5 = 15,036 lb 08 April 2008
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F p = wf ub L p
4.5 Compute Unbalanced Load on Piles to check against Σ Pall ΣP all
Fp = wf ub L p w = Monolith width or Pile Spacing
f ub
Fub = Lu
Fub = Total unbalanced force per foot from Step 2 Lu and Lp as defined in paragraph 4.1 08 April 2008
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4.5 Fub ub = Total unbalanced force per foot from Step 2 = 5,350 lb/ft Luu = 22.4 ft Lpp = 17.9 ft fub ub = 5,350 lb/ft / 22.4 ft = 239 lb/ft/ft Fpp = 5 ft x 239 lb/ft/ft x 17.9ft = 21,391 lb
f ub
Fub = Lu
Fup = wf ub L p
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4.5 Pall If 50% of Fpp < Σ ΣP all then OK If 50% of Fpp > Σ Pall ΣP all then: compute Σ Pall ΣP all for all of the piles If Σ Pall ΣP all for all piles > Fp p then OK If Σ Pall ΣP all for all piles < Fp p then Redesign
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4.5 Fpp = 21,391 lb 50% of Fpp = 21,391 lb(0.50) = 10,695 lb ΣPall = 15,036 lb
> 10,695 lb
OK
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4.6 Second Flow Through Check
Shear Along Planes Bounded by Piles
10 ft
Unbalanced Force Below Pile Cap,
Shear Area bounded by piles, Ap
Lp= 17.9 ft
fubLp 1 3
Critical Failure Surface 21.9 ft
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A S ⎛⎡10 ft + 21 ⎤ .9 ft ⎞ Af ubp SLup =≤17.p9 ftu ⎜⎢ 2 ⎥ ⎟(120 psf ) = 34,260lb ⎠ FS ⎝⎣ ( st − b2) ⎦
4.6 Ap S u ⎡ 2 ⎤ f ub L p ≤ ⎢ ⎥ FS ⎣ ( st − b) ⎦ AppSuu = The area bounded by the bottom of the T -wall T-wall base, the critical failure surface, the upstream pile row and the downstream pile row multiplied by the shear strength of the soil within that area. For layered soils, the product of the area and Su for each layer is computed and added for a total ApSu ApSu.. See Figure 3. FS = Target factor of safety used in Steps 1 and 2. = 1.5 08 April 2008
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f ub L p ≤
Ap S u ⎡ 2 ⎤ ⎢ ⎥ FS ⎣ ( st − b) ⎦
4.6 Ap S u ⎡ 2 ⎤ f ub L p ≤ ⎢ ⎥ FS ⎣ ( st − b) ⎦ stt = the spacing of the piles transverse (perpendicular) to the unbalanced force = 5 ft b = pile width = 14 in
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f ub L p ≤
Ap S u ⎡ 2 ⎤ ⎢ ⎥ FS ⎣ ( st − b) ⎦
4.6 ⎛ 10 ft + 21.9 ft ⎞ A p S u = 17.9 ft ⎜ ⎟(120 psf ) = 34,260lb 2 ⎝ ⎠
⎡ ⎤ ⎥ A p S u ⎡ 2 ⎤ 34,260 ⎢ 2 ⎢ ⎥ = 11,917 ⎢ ⎥= 1.5 ⎢ ⎛ 14 ⎞ ⎥ FS ⎣ ( st − b) ⎦ ⎢ 5 − ⎜⎝ 12 ⎟⎠ ⎥ ⎣ ⎦
Ap S u ⎡ 2 ⎤ f ub L p ≤ ⎢ ⎥ FS ⎣ ( st − b) ⎦ fub ubLpp = (239 lb/ft)(17.9 ft) = 4,278 lb/ft OK
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162
Step 5 Group 7 Analysis 5.1 Only Critical Load Cases.
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5.2 Apply ““Structural” Structural” loads at base and above to wall. (Water, Soil, Dead Loads).
Water and Dead Loads
Hydrostatic Force
Unbalanced Force, Fub
Unbalanced Load Applied Directly to Piles
Uplift
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5.3 • Look at flood side row with 50% Unbalance Force • If n ΣPult nΣP ult > 50% Fpp then 50% Unbalanced Force on
Floodside row 0.5fub ubstt and the rest equally on remaining rows • If n ΣPult nΣP ult < 50% Fpp then load = Pult ult on Flood side row and the rest equally on remaining rows • Pult ult Not Pall all
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5.3 • Check if (nΣPult ult) of the flood side pile row is
greater than 50% Fpp, (from 4.5)
.
• (nΣPult ult) = 1 (22,554 lb) = 22,554 lb • 50% Fpp = (0.50)(21,391) = 10,696 lb • Since nΣPult ult > 50% Fpp, then 50% Fpp will be applied
to the flood side piles - uniform load =0.5fub ubstt - remaining 50% Fpp will be applied equally to the remaining piles.
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5.3 Distribute 50% of Fpp onto the flood side (left) row of piles: • 0.5fub ubstt = 0.5 (239 lb/ft/ft)(5 ft) • = 597.5 lb/ft = 50 lb/in The remainder is divided among the remaining piles. • Middle pile = 25 lb/in • Right pile =25 lb/in
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5.3 Check of Pile Stresses 100 % Fpp applied to the flood side piles, < nΣPult ult Verify that 100% Fpp does not exceed nΣPult ult: 100%Fpp = 21, 391 lb nΣPult ult = 1 (22,554 lb) = 22,554 lb Since, 100% Fpp < nΣPult ult, 100% Fpp distributed on the flood side piles fub ubstt = (239 lb/ft/ft)(5 ft) = 1,195 lb/ft = 100 lb/in 08 April 2008
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5.5
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5.6 Can use Group developed PY curves Curves on piles from bottom of cap to lowest elevation of failur e failure surface are adjusted to account for moving soil mass Clay stiffness stiffness depends depends on on C C and and e50 e50 Sand stiffness depends on k and Phi If FS < 1.0 then remove lateral resistance by making cohesion in soil layers very small (or k for sands) IF FS >1.0 then ratio lateral resistance by ratio of factor of ssafety afety between 1.0 and and target target factor factor of of safety safety –– Multipy Multipy Cohesion Cohesion (or (or k) by this percentage
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5.6 Our example FS = 0.98 C = 0.0001 e50 does not need to be adjusted K not used for Soft Clays
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Step 5
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5.6, 5.7 • Compare output with allowables • HSDRS Design Guides • EM1110 -2-2906 EM1110-2-2906 • Axial and Shear in Piles •• Are Are compared compared with with results results from from Step Step 33 •• Shear Shear found found at at lowest lowest critical critical surface surface elevation elevation compared compared
to to capacity capacity in in Step Step 33
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5.6, 5.7 Pervious Case – 50% on Floodside Pile Pile 1 Right Right 2 Center 3 Left
Axial (k) 2.3 2.3 (C) (C) 93.5 (C) -39.9 (T)
Shear (k) 3.2 3.2 2.9 5.2
Max Moment (k-in) -227 -227 -207 314
Pervious Case – 100 % on Floodside Pile Pile 1 Right Right 2 Center 3 Left
Axial (k) 1.3 1.3 (C) (C) 98.6 (C) -39.2 (T)
Shear (k) 1.8 1.8 1.6 8.7
Max Moment (k-in) -229 -229 -206 838
08 April 2008
174 One Team: Relevant, Ready, Responsive and Reliable
5.6, 5.7 Impervious Case – 50% on Floodside Pile Pile 1 Right Right 2 Center 3 Left
Axial (k) 9.2 9.2 (C) (C) 91.5 (C) -35.8 (T)
Shear (k) 3.1 3.1 2.9 5.2
Max Moment (k-in) -217 -217 -198 318
Impervious Case – 100 % on Floodside Pile Pile 1 Right Right 2 Center 3 Left
Axial (k) 8.4 8.4 (C) (C) 96.2 (C) -34.9 (T)
Shear (k) 1.7 1.7 1.6 8.7
08 April 2008
Max Moment (k-in) -216 -216 -193 843
175 One Team: Relevant, Ready, Responsive and Reliable
5.6, 5.7 Table Displacement of grouped pile foundation Load Case Pervious Impervious Pervious Impervious
Load % 50% 50% 100% 100%
Horz (in) 0.53 0.49 0.56 0.52
08 April 2008
Vert (in) -0.21 -0.18 -0.22 -0.20
176 One Team: Relevant, Ready, Responsive and Reliable
Step 6 (Optional) NOT SHOWN
Unbalanced Force, Fub
08 April 2008
177 One Team: Relevant, Ready, Responsive and Reliable
Step 7 (Optional) NOT COMPLETED Global Stability Analysis with pile forces as reinforcement.
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08 April 2008
178 One Team: Relevant, Ready, Responsive and Reliable
Question?
Thank You 08 April 2008
179 One Team: Relevant, Ready, Responsive and Reliable
Guidance on Long Structures And Trailing Structures by by
Rich Varuso, P.E. April April 8, 8, 2008 2008
One Team: Relevant, Ready, Responsive and Reliable
Long Structures
0.7H 0.7H 0.7H 08 April 2008
181 One Team: Relevant, Ready, Responsive and Reliable
Adjacent Structures
Unbalanced Load FOS < 1.5
FOS > 1.5
08 April 2008
182 One Team: Relevant, Ready, Responsive and Reliable
Question?
Thank You 08 April 2008
183 One Team: Relevant, Ready, Responsive and Reliable
Results of Ongoing Sensitivity Analysis by by
Bob Yokum, P.E. April April 8, 8, 2008 2008
One Team: Relevant, Ready, Responsive and Reliable
On -going Sensitivity Analysis On-going • Develop a systematic approach for selecting trial surfaces
and managing search routines for UT4 and Slope W
• For 5 T-wall examples we compared MOP vs Spencers for
both UT4 and Slope W (FOS and Unbalanced Load)
• For 5 T-wall examples we compared MOP vs Spencers
using both UT4 and Slope W.
• We utilized the results from the new T-wall procedure to
compare pile loads, pile stress and pile cap deflection for • Steel H-piles • Concrete piles 08 April 2008 • Combination of steel and concrete piles One Team: Relevant, Ready, Responsive and Reliable
185
On -going Sensitivity Analysis On-going • We compared the effects of different pile spacing reduction
factors.
• EM – 1110-2-2906 • G-pile default values
Analyzed the foundations with only the unbalanced load applied along the length of the pile. • Analyzed the foundations with both the unbalanced load
applied along the length of the pile and the super-structure loading.
• Plugged in the appropriate loads from G-pile into the
stabilty analysis to determine the FOS for both cases listed above.
08 April 2008
186
One Team: Relevant, Ready, Responsive and Reliable
Preliminary Findings/Results • Variation in Pile Types • Steel vs. Concrete • Mixed Foundations • Pile Spacing Reduction • Lateral Deflections • Maximum Moments • Group Input Simplification • Strata Unit Weights • Strata Shear Strengths • Soil Stiffness 08 April 2008
187 One Team: Relevant, Ready, Responsive and Reliable
Preliminary Findings/Results • Output Interpretation • Local Forces • Moments and Stresses Steel vs. Concrete • Input / Output Choices • General Recommendations • Preliminary Foundation Design • Geotechnical Data Preparation and
GROUP Input • Common Mistakes / Error Messages • You’re Already Late
08 April 2008
188 One Team: Relevant, Ready, Responsive and Reliable
Preliminary Findings/Results • Output Interpretation • Local Forces • Moments and Stresses Steel vs. Concrete • Input / Output Choices • General Recommendations • Preliminary Foundation Design • Geotechnical Data Preparation and
GROUP Input • Common Mistakes / Error Messages • You’re Already Late
08 April 2008
189 One Team: Relevant, Ready, Responsive and Reliable
Q&A Panel Kent Hokens, P.E. Neil Schwanz, P.E. Mark Gonski, P.E. Richard Pinner, P.E. Rob Werner Bob Yokum, P.E. April April 8, 8, 2008 2008 One Team: Relevant, Ready, Responsive and Reliable
