GEOLOGICAL DEPENDENCE OF RESISTANCE FACTORS FOR DEEP FOUNDATION DESIGN

2013·10.8 MB·English

by  Vu, Cuong Quoc

GEOLOGICAL DEPENDENCE OF RESISTANCE FACTORS
FOR DEEP FOUNDATION DESIGN
by
CUONG VU
B.S. Civil Engineering, Hanoi University of Civil Engineering, 2001
M.S. Civil Engineering, University of Colorado at Boulder, 2004

A thesis submitted to the
Faculty of the Graduate School of the
University of Colorado in partial fulfillment
of requirement for degree of
Doctor of Philosophy
Civil Engineering

2013
© 2013 by Cuong Vu
All rights reserved
This thesis for the Doctor of Philosophy degree by
Cuong Vu
has been approved for the
Civil Engineering Program
by

Nien-Yin Chang, Chair
Stein Sture
Brian Brady
Jimmy Kim
Trever Wang
Aziz Khan

Date: April 18, 2013

ii
Cuong Vu (PhD, Civil Engineering)
Geological Dependence of Resistance Factors for Deep Foundation Design
Thesis directed by Professor Nien-Yin Chang

ABSTRACT
This research addresses the issue of geological dependence of deep foundation
designs resistance factors for driven pile and drilled shaft designs in different
locations. For the proof, two sets of databases were used: one from the NCHRP 507
report and another driven pile and drilled shaft database with static load tests and soil
profiles from the different locations in Vietnam were used to evaluate resistance
factor design for different axial pile capacity prediction methods. Eight different static
analysis methods were used for driven pile capacity evaluation: α- Tomlinson, α-API,
λ, β, Nordlund, Thurman, Meyerhof SPT, and the Shmertmann SPT method. For
drilled shafts the FHWA and Reese & Wight methods were used. In the analyses the
correlations between Nspt and soil parameters were used. First Order Second Moment
(FOSM), First Order Reliability Methods (FORM) and Monte Carlo simulations were
used to evaluate the based analyses in the determination of the resistance factors (Φ).
The following notable benefits were attained in this project: 1) Resistance factors are
made available for the LRFD designs of driven piles and drilled shafts in Vietnam; 2)
The results show that the resistance factors vary with methods, geomaterial types and
geological locations; 3) The found resistance factors (Φ) for Vietnam give
substantially greater factored capacities as compared to the 2012 AASHTO-LRFD
recommendations

The form and content of this abstract are approved. I recommend its publication.

Approved: Nien-Yin Chang
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ACKNOWLEDGEMENTS

I am indebted, first and foremost, to my advisor Dr. Nien-Yin Chang for providing
me the guidance and support and for his tireless advice during my study for this
dissertation. I would also like to thank Dr. Stein Sture, Dr. Brian Brady, Dr. Jimmy
Kim, Dr. Trever Wang and Dr. Aziz Khan for serving on the final examination
committee. I would like to express my special thanks to my wife, Lan Anh Nguyen,
for many years of her endurance, sacrifice, assistance, and encouragement, which
made this accomplishment possible. I also thank my parents and my brother for their
support and all of my friends who helped me in many ways to accomplish this
research.

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CONTENTS

Figures........................................................................................................................v
Tables .........................................................................................................................vii

Chapter
1. Introduction ............................................................................................................1
1.1 Problem statement ................................................................................................1
1.2 Research objective ...............................................................................................2
1.3 Research approach ...............................................................................................2

2. Literature Review ...................................................................................................4
2.1 History of LRFD Development ...........................................................................4
2.2 Review of the Recommended Load Factors for Piles Designs ............................10
2.3 ASD versus LRFD ...............................................................................................16
2.3.1 Allowable Stress Design (ASD) ......................................................................17
2.3.2 Load and Resistance Factor Design (LRFD) ...................................................19

3. Axial Pile Capacity Prediction Methods ................................................................21
3.1. Axial Loading Capacity of a Driven Pile ............................................................21
3.1.1. Side resistance in cohesive soil ........................................................................22
3.1.1.1. α-Tomlinson method ....................................................................................22
3.1.1.2. α-API revised method (1987) ......................................................................24
3.1.1.3. β-Burland method (1973) ............................................................................25
3.1.1.4. λ-Method .......................................................................................................27
3.1.2. Tip resistance in cohesive soil .........................................................................28
3.1.3 Side resistance in cohesionless soil ...................................................................29
3.1.3.1 β-Bushan method (1982) ..............................................................................29
3.1.3.2 Nordlund method ...........................................................................................29
3.1.4. Tip resistance in cohesionless soil--Thurman method .....................................33
3.1.5. Empirical Methods ...........................................................................................35
3.1.5.1 Meyerhof method for piles in cohesionless soil ............................................35
3.1.5.2 Schmertmann method for SPT .......................................................................36
3.1.5.3 Nottingham and Schmertmann method for CPT ...........................................39
3.2 Axial Loading Capacity of a Drilled Shaft ..........................................................43
3.2.1 Side resistance in cohesive soils .......................................................................43
3.2.1.1 FHWA method ...............................................................................................43
3.2.2 End bearing in cohesive soils ............................................................................45
3.2.2.1 FHWA method ...............................................................................................45
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3.2.3 Skin resistance in cohesionless soil ..................................................................46
3.2.3.1 FHWA method ...............................................................................................46
3.2.3.1 Reese and Wright method ..............................................................................47
3.2.4 End bearing in cohesionless soil .......................................................................47
3.2.4.1 FHWA method ...............................................................................................47
3.2.4.2 Reese and Wright method ..............................................................................48
3.2.5 Side resistance in rock ......................................................................................48
3.2.6 Tip resistance in rock ........................................................................................49
3.3 Piles Dynamic Analysis .......................................................................................51
3.3.1 The Case Method ..............................................................................................51
3.3.2 The Energy Approach .......................................................................................52
3.3.3 PDA Signal Matching Using CAPWAP ...........................................................52
3.4 Static Load Test ...................................................................................................53
3.4.1 ASTM Procedures .............................................................................................53
3.4.1.1 Standard Load Test Procedures .....................................................................53
3.4.1.2 Cyclic Load Test ............................................................................................54
3.4.1.3 Quick Load Test Method for Individual Piles ...............................................54
3.4.1.4 Constant Rate of Penetration .........................................................................55
3.4.2 Vietnamese Load Test Procedures ....................................................................55
3.5 Interpretation of Pile Load Test Results ..............................................................55
3.5.1 Davisson’s Method ...........................................................................................55
3.5.2 The Limit Total Settlement Method .................................................................57
3.5.3 DeBeer's Method ...............................................................................................57
3.5.4 Chin’s Criterion ................................................................................................58
3.6 Soil Properties from Insitu Tests..........................................................................59
3.6.1 Correlations between soil properties and SPT ..................................................60
3.6.1.1 Undrained shear strength Su ..........................................................................60
3.6.1.2 OCR for clay ..................................................................................................61
3.6.1.3 Effective stress friction angle of cohesionless soil ........................................62
3.6.1.4 Relative Density D of Cohensionless Soil ....................................................63
r
3.6.2 Correlations between soil properties and CPT ..................................................64
3.6.2.1 Undrained shear strength S ...........................................................................64
u
3.6.2.2 OCR for cohesive soil - Mayne .....................................................................64
3.6.2.3 The effective stress friction angle for cohensionless soil ..............................65
3.6.2.4 Relative Density D of Cohensionless Soil- Jamiolkowski ............................66
r
3.6.3 Undrained Shear Strength of Clay vs Index Properties ....................................67

4. Evaluation of Resistance Factors By Calibration ..................................................68
4.1 Fitting ASD to LRFD ...........................................................................................69
4.2 Reliability Analysis ..............................................................................................69
4.2.1 Resistance bias factor ........................................................................................70
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4.2.2 Probability density function ..............................................................................71
4.2.3 The First Order Second Moment (FOSM) Method ..........................................72
4.2.3.1 Reliability index β ..........................................................................................72
4.2.3.2 Recommended Target Reliability Index ........................................................79
4.2.3.3. Efficiency of Different Methods ...................................................................80
4.2.3.4 Equivalent Factor of Safety ...........................................................................80
4.2.3.5 Resistance Factor Calibration ........................................................................81
4.2.4 First-Order Reliability Method (FORM) Analysis ...........................................82
4.2.5 Monte Carlo Simulation Method ......................................................................86

5. Resistance Factor Calibration for the Data from Difference Locations in NCHRP
Report 507 ..................................................................................................................90
5.1 Introduction .........................................................................................................90
5.2 Calibration Resistant Factor for Driven Piles Using CAPWAP Method ............90
5.2.1 Resistance Factor for Different Locations by Using CAPWAP
(BOR+EOD) Data .............................................................................................90
5.2.2 Resistance Factor for Different Locations by Using CAPWAP
(BOR) Data .......................................................................................................94
5.2.3 Resistance Factor for Different Locations by Using CAPWAP
(EOD) Data .......................................................................................................96
5.3 Calibration Resistant Factor for Driven Piles Using Static Analysis ..................98
5.3.1 Resistance Factor for Concrete Piles in Cohesionless for
Different Locations ...........................................................................................98
5.3.2 Resistance Factor for Concrete Piles in Cohesive for
Different Locations ...........................................................................................99
5.3.3 Resistance Factor for Concrete Piles in Mixed soil for
Different Locations ...........................................................................................100

6. Data Collection from Vietnam ...............................................................................101
6.1 Introduction .........................................................................................................101
6.2 General description of Vietnam geology .............................................................102
6.2.1 North Vietnam ..................................................................................................102
6.2.2 South Vietnam ..................................................................................................106
6.2.3 Central Vietnam ................................................................................................107
6.3 Static Load Tests and Soil Profile from a site in Vietnam ...................................108

7. Calibration Resistance Factor for Driven Piles in Vietnam ...................................113
7.1 Procedure to Calibrate Resistance Factors for Driven Piles ................................113
7.2 Collection of Driven Piles in Vietnam .................................................................114
7.3 Measurement capacity of driven piles .................................................................114
7.4 Nominal Capacity of driven piles ........................................................................114
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7.4.1Nominal Capacity of Concrete Piles in Cohesionless Soils ...............................115
7.4.2 Nominal Capacity of Concrete Piles in Cohesive Soils ....................................118
7.4.3 Nominal Capacity of Concrete Piles in Mixed Soils .......................................118
7.5 Calibration of Resistance Factors .......................................................................131
7.5.1 Resistant factor for driven pile in Sand .............................................................132
7.5.2 Resistant factor for driven pile in Clay .............................................................137
7.5.3 Resistant factor for driven pile in Mixed Soil ...................................................143

8. Calibration Resistance Factors for Drilled Shaft in Vietnam ................................161
8.1 Procedure to Calibrate Resistance Factors for Drilled Shaft ...............................161
8.2 Collection of Drilled Shaft in Vietnam ................................................................161
8.3 Measurement Capacity of drilled Shaft ...............................................................162
8.4 Nominal Capacity of Drilled Shaft ......................................................................162
8.4.1 Nominal Capacity of Concrete Piles in Mixed Soils ........................................162
8.5 Calibration of Resistance Factors for Drilled Shaft .............................................167
8.5.1 Resistant factor for drilled shaft in Mixed Soil .................................................167
8.5.2 Statistical sample size requirements for calibration the resistance factor for
drilled shafts in Vietnam ............................................................................................178

9. Conclusions and Recommendation ........................................................................180
9.1 Summary of Research ..........................................................................................180
9.2 Major Outcomes and Conclusions .......................................................................181
9.3 Recommendations ................................................................................................182
9.4 Future Research ...................................................................................................183

Appendix
A. Calibration Resistance Factor by Using FORM for Driven Pile using
CAPWAP Method ...............................................................................................184
B. Calibration Resistance Factor by Using FORM for Driven Pile using Static
Analysis................................................................................................................211
C. Calibration Resistance Factor by Using FOSM for Driven Pile using
CAPWAP Method ...............................................................................................239
D. Calibration Resistance Factor by Using FOSM for Driven Pile using Static
Analysis................................................................................................................266
E. Nominal and Measure Capacity of Driven Pile from Vietnam .............................275
F. Histogram and Frequency Distribution of Bias Factor for Driven Piles from
Vietnam ................................................................................................................297
G. Nominal and Measure Capacity of Drilled Shaft from Vietnam ..........................390
H. Histogram and Frequency Distribution of Bias Factor for Drilled Shaft ..............398

References ..................................................................................................................422
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FIGURES
Figure
1.1 LRFD implementation for bridge foundations from survey in 2008 ...................9

2.1 Factor of Safety ....................................................................................................13
2.2 LRFD Design Approach ......................................................................................15

3.1a Adhesion values for piles in cohesive soils (after Tomlinson, 1979) ...............23
3.1b α factors; Tomlinson Method (Tomlinson, 1995) ............................................24
3.2 Comparison between α-Factors Calculated form API 1986 and 1987 ................25
3.3 β factors (AASHTO 2007) .................................................................................27
3.4 Coefficient for driven pile piles after Vijayvergiya and Focht (1972) ...............28
3.5 Design curve for evaluating Kδ when φ = 25 (Hannigan et al., after
Nordlund, 1979) ..................................................................................................30
3.6 Design curve for evaluating Kδ when φ = 30 (Hannigan et al., after
Nordlund, 1979) ...................................................................................................31
3.7 Design curve for evaluating Kδ when φ = 35 (Hannigan et al., after
Nordlund, 1979) ...................................................................................................31
3.8 Design curve for evaluating Kδ when φ = 40 (Hannigan et al., after
Nordlund, 1979) ..................................................................................................32
3.9 Relation δ/φ and pile displacement (Hannigan et al., after Nordlund, 1979) ......32
3.10 Correction factor (CF) for Kδ (Hannigan et al., after Nordlund, 1979) ..........33
3.11 αT coefficient (FHWA--DRIVEN, 1998) ........................................................34
3.12 Bearing capacity factor Nq’(FHWA--DRIVEN, 1998) ....................................34
3.13 Relationship between Maximum Unit Pile Toe Resistance qL (kPa)
and Friction Angle for Cohesionless Soils (Meyerhof, 1976/1981). ................35
3.14 Ks and Kc ratio in cohesionless and cohesive soil, respectively (cited in
McVay and Townsend, 1989) ..........................................................................39
3.15 Tip resistance computation procedure--Nottingham 1975. (cited in McVay
and Townsend, 1989) .......................................................................................40
3.16a Ks ratio in cohesionless ....................................................................................41
3.16b Kc ratio in cohesive soil ...................................................................................42
3.17 Explanation of Portions of Drilled Shaft Not Considered in Computing
Side Resistance in Clay (O’Neilll and Reese, 1999) .......................................44
3.18 Static pile load testing procedures according to ASTM ....................................53
3.19 Graphical representation of Davisson criterion .................................................55
3.20 Graphical representation of DeBeer method ......................................................56
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