practical implementation of lrfd for geotechnical...

Practical Implementation of LRFD for

Geotechnical Engineering Features

Design and Construction of Driven Pile Foundations

Wednesday, June 22, 2011

PDCA Professors Workshop

By

Jerry A. DiMaggio, PE, D. GE, M. ASCE

E-Mail: [email protected]

1

ASCE LRFD Webinar Series

2

* Check ASCE website for latest information

# Topic 2009 2010 2011 2012

1 Fundamentals of LRFD – Part 1 1/16, 8/7 6/30 1/18, 10/13

2 Fundamentals of LRFD – Part 2 1/30, 9/8 7/15 2/4, 10/21

3 Subsurface Explorations 6/30, 11/5 4/15 2/17, 8/18 2/3

4 Shallow Foundations 7/24 1/6, 5/7, 11/8 5/20, 12/12

5 Deep Foundations – Piles 1/25, 6/1, 12/14 6/21, 11/7

6 Deep Foundations – Shafts 2/8, 6/11 1/7, 7/8 1/23

7 Deep Foundations – Micropiles 9/10 3/3, 7/29 1/12

8 Earth Retaining Structures – Fill 8/20 3/11, 9/12 3/9

9 Earth Retaining Structures – Cut 10/21 9/30 2/28

10 MSE Walls 4/4, 12/2

11 Ground Anchors 5/2 3/29

Presnetation Assumptions/References

• Basic knowledge of:

– LRFD (previous webinars)

– Basic Deep Foundation Design and Construction

• Primary References:

– Section 10 of AASHTO (2010, 5th Edition)

– List of other references provided at end

3

Driven Pile Foundations

Topic Slides

General (Section 3, Section 10.4, 10.7.1) 4 – 18

10.5 Limit States and Resistance Factors 19 – 22

10.7.2 Service Limit State 23 – 31

10.7.3 Strength Limit State 32 – 58

10.7.4 Extreme Event Limit State 59 – 65

10.7.5 Corrosion and Deterioration 66 – 69

10.7.8 Drivability Analysis 70 – 73

4

Section 10 Contents

Article Topic

10.1 Scope

10.2 Definitions

10.3 Notation

10.4 Soil and Rock Properties

10.5 Limit States and Resistance Factors

10.6 Spread Footings

10.7 Driven Piles

10.8 Drilled Shafts

10.9 Micropiles

Refer to Section 3 for Loads and Load Factors

5

Deep Foundation Types

Material Driven

Piles

Drilled

Shafts/

Micropiles

Jacked/

Special

Prestressed concrete X X

Post-tensioned concrete X X

Pre-cast concrete X

Cast-in-place concrete X X X

Steel X X X

Wood X

Specialty/Composites X X X

6

Section 10.7 Driven Piles

Article Topic

10.7.1 General

10.7.2 Service Limit State Design

10.7.3 Strength Limit State Design

10.7.4 Extreme Event Limit State Design

10.7.5 Corrosion and Deterioration

10.7.6 Minimum Pile Penetration

10.7.7 Driving Criteria for Bearing

10.7.8 Drivability Analysis

10.7.9 Test Piles

7

Professional Discipline Communication

• Geotechnical, Structural, Hydraulic, and Construction

specialists all play an important role and have

different responsibilities on deep foundation

projects.

• Project specific loads, extreme events, performance

requirements, scour, pile cap details, specifications,

plans construction, pile damage are ALL KEY issues

for a successful project!

• The Geotechnical Design Report is a key

communication tool.

8

10.7.1 GENERAL

• Consider spread footings first.

• Basic guidelines for driven pile configurations

– Minimum spacing 2.5 pile diameters or 30 inches.

– Minimum of 9 inches pile cap edge and be embedded 12

inches into the pile cap or if with strands or bars then the

pile embedment should be 6 inches.

– Piles through embankments should extend 10 ft into

original ground or refusal on rock. Maximum of 6 inch fill

size.

– Batter Piles: stiffness, don’t use in downdrag situations,

concern in seismic situations.

9

Comparison of LRFD and ASD approaches

for Deep Foundations

Same Different

• Determining resistance • Comparison of load and resistance

• Determining deflection • Separation of resistance and deflection

10

AASHTO Table 3.4.1-1

Load

Combination

Limit State

DC

DD

DW

EH

EV

ES

EL

PS

CR

SH

LL

IM

CE

BR

PL

LS WA WS WL FR TU TG SE

Use One of These at

a Time

EQ IC CT CV

STRENGTH

LIMIT

I γp 1.75 1.00 — — 1.00 0.50/1.20 γTG γSE — — — —

II γp 1.35 1.00 — — 1.00 0.50/1.20 γTG γSE — — — —

III γp — 1.00 1.40 — 1.00 0.50/1.20 γTG γSE — — — —

IV γp — 1.00 — — 1.00 0.50/1.20 — — — — — —

V γp 1.35 1.00 0.40 1.0 1.00 0.50/1.20 γTG γSE — — — —

EXTREME EVENT

I γp γEQ 1.00 — — 1.00 — — — 1.00 — — —

II γp 0.50 1.00 — — 1.00 — — — — 1.00 1.00 1.00

SERVICE LIMIT

I 1.00 1.00 1.00 0.30 1.0 1.00 1.00/1.20 γTG γSE — — — —

II 1.00 1.30 1.00 — — 1.00 1.00/1.20 — — — — — —

III 1.00 0.80 1.00 — — 1.00 1.00/1.20 γTG γSE — — — —

IV 1.00 — 1.00 0.70 — 1.00 1.00/1.20 — 1.0 — — — —

FATIGUE - LL, IM & CE only

I — 1.50 — — — — — — — — — — —

II — 0.75 — — — — — — — — — — —

11

Load

Combination

Limit State

DC

DD

DW

EH

EV

ES

EL

PS

CR

SH

LL

IM

CE

BR

PL

LS WA WS WL FR TU TG SE

Use One of These at

a Time

EQ IC CT CV

STRENGTH

LIMIT

I γp 1.75 1.00 — — 1.00 0.50/1.20 γTG γSE — — — —

II γp 1.35 1.00 — — 1.00 0.50/1.20 γTG γSE — — — —

III γp — 1.00 1.40 — 1.00 0.50/1.20 γTG γSE — — — —

IV γp — 1.00 — — 1.00 0.50/1.20 — — — — — —

V γp 1.35 1.00 0.40 1.0 1.00 0.50/1.20 γTG γSE — — — —

EXTREME EVENT

I γp γEQ 1.00 — — 1.00 — — — 1.00 — — —

II γp 0.50 1.00 — — 1.00 — — — — 1.00 1.00 1.00

SERVICE LIMIT

I 1.00 1.00 1.00 0.30 1.0 1.00 1.00/1.20 γTG γSE — — — —

II 1.00 1.30 1.00 — — 1.00 1.00/1.20 — — — — — —

III 1.00 0.80 1.00 — — 1.00 1.00/1.20 γTG γSE — — — —

IV 1.00 — 1.00 0.70 — 1.00 1.00/1.20 — 1.0 — — — —

FATIGUE - LL, IM & CE only

I — 1.50 — — — — — — — — — — —

II — 0.75 — — — — — — — — — — —

DC DW DW EH

EV

ES

LL

WA WA

EQ CT

DD

12

Load Factors for Permanent Loads, γp

Type of Load, Foundation Type, and

Method Used to Calculate Downdrag

Load Factor

Maximum Minimum

DC: Component and Attachments

DC: Strength IV only

1.25

1.50

0.90

0.90

DD: Downdrag Piles, α Tomlinson Method

Piles, λ Method

Drilled shafts, O’Neill and Reese (1999) Method

1.4

1.05

1.25

0.25

0.30

0.35

DW: Wearing Surfaces and Utilities 1.50 0.65

EH: Horizontal Earth Pressure

• Active

• At-Rest

• AEP for anchored walls

1.50

1.35

1.35

0.90

0.90

N/A

EL: Locked-in Construction Stresses 1.00 1.00

EV: Vertical Earth Pressure

• Overall Stability

• Retaining Walls and Abutments

• Rigid Buried Structure

• Rigid Frames

• Flexible Buried Structures other than Metal Box Culverts

• Flexible Metal Box Culverts and Structural Plate Culverts with Deep

Corrugations

1.00

1.35

1.30

1.35

1.95

1.50

N/A

1.00

0.90

0.90

0.90

0.90

ES: Earth Surcharge 1.50 0.75

AASHTO Table 3.4.1-2

13

Load Type and Direction

Structural Geotechnical

• Vertical or horizontal

• Permanent/Transient

• Vertical/Horizontal

• Downdrag/Setup/Relaxation

New

Fill

Bridge Deck

Soft Soil Consolidating

Due to Fill Weight

Bearing Stratum

New

Fill

New

Fill

Bridge Deck


Due to Fill Weight

Bearing Stratum

14

Downdrag

15

Design Method Load Factors

Maximum Minimum

Piles α-method 1.40 0.25

λ-method 1.05 0.30

Shafts Reese & O’Neill (1999) 1.25 0.35

• “Geotechnical” load

• Can be significant particularly given the max load factors

• Articles 3.4.1 and 3.11.8

New

Fill

Bridge Deck


Due to Fill Weight

Bearing Stratum

New

Fill

New

Fill

Bridge Deck


Due to Fill Weight

Bearing Stratum

15

AASHTO Section 10.4

Soil and Rock Properties

DISCUSSED IN PREVIOUS WEBINAR ON

SUBSURFACE INVESTIGATIONS – Next Offering

on August 18, 2011

Article Topic

10.4.1 Informational Needs

10.4.2 Subsurface Exploration

10.4.3 Laboratory Tests

10.4.4 In Situ Tests

10.4.5 Geophysical Tests

10.4.6 Selection of Design Properties

16

Deep Foundation Selection

• Method of support

• Bearing material depth

• Load type, direction and magnitude

• Constructability

• Cost

� Expressed in $/kip capacity

� Include all possible costs

17

Pile Types Based on Soil Displacement

During Driving

Low Displacement High Displacement

18


Topic Slides








19

Strength Limit State Driven Piles

ARTICLE 10.5.3.3

• Axial compression resistance for single piles

• Pile group compression resistance

• Uplift resistance of single piles

• Uplift resistance of pile groups

• Pile punching failure in weaker stratum

• Single pile and pile group lateral resistance

• Constructability, including pile drivability

20

SPECIAL DESIGN CONSIDERATIONS

• Negative shaft resistance (downdrag)

• Lateral squeeze

• Scour

• Pile and soil heave

• Seismic considerations

21

10.5 LIMIT STATES AND RESISTANCE

• Strength Limit State (will be discussed later)

– Structural Resistance

– Geotechnical Resistance

– Driven Resistance

• Service Limit State

– Resistance Factor = 1.0 (except for global stability)

• Extreme Event Limit State

– Seismic, superflood, vessel, vehicle

– Use nominal resistance

22


Topic Slides








23

Service Limit State Checks

Global Stability Vertical and

Horizontal

Displacements

24

Settlement of Pile Groups

Article 10.7.2.3.1 [Hannigan (2006)]

• Treat as

equivalent

footings

• Categorize

as one of

the 4 cases

shown

here

25

Fx

H1 H2

∆∆∆∆x ∆∆∆∆x

M1 M2

10.7.2.4 Horizontal Loads and Pile Moments

26

Horizontal Response

• Assumes nominal resistance is adequate

• No consideration of possible brittle response

of geomaterial

• LPILE type p-y model or Strain Wedge Method

Isolated Group

27

De

pth

, ft

P-y Results for Single Element

28

P-y Results for Pile Groups

Spacing (S) P-multiplier (Pm)

Row 1 Row 2 Row 3

3B 0.8 0.4 0.3

5B 1.00 0.85 0.7

Applied LoadB

Spacing

Row

3 or higher

Row

2

Row

1

Applied Load

Row

3 or higher

Row

2

Row

1

Spacing

Row 1

Applied Load

5B or less

Applied LoadB

SpacingSpacing

Row

3 or higher

Row

2

Row

1

Applied Load

Row

3 or higher

Row

2

Row

1

Spacing

Row 1

Applied Load

5B or less

AASHTO Figure 10.7.2.4-1

29

∆∆∆∆x ∆∆∆∆x

Moment Moment

Pile Head Fixity

30

30

Tolerable Movements and Movement

Criteria 10.5.2.2

• Service loads for settlements,

horizontal movements and

rotations.

• Omit transient loads for

cohesive soils

• Reference movements to the

top of the substructure unit.

• Angular Distortion (C10.5.2.2)

31


Topic Slides








32

33

STRENGTH LIMIT STATES

Structural

Axial

Driven

(Assess Drivability)

Flexure

Shear

Geotechnical Axial

33

Axial compression

Combined axial and flexure

Shear

LRFD Specifications

Concrete – Section 5

Steel – Section 6

Wood – Section 8

Methods for Determining Structural

Resistance

34

Factors Affecting

Allowable Structural Pile Stresses

• Average section strength (Fy, fc’, wood crushing

strength)

• Defects (knots in timber)

• Section treatment (preservation for timber)

• Variation in materials

• Load factor (overloads or pile damage)

35

Concrete (5.5.4.2)

Axial Comp. = 0.75

Flexure = 0.9 (strain dependent)

Shear = 0.9

Steel (6.5.4.2)

Axial = 0.5-0.7

Combined

Axial= 0.7-0.8

Flexure = 1.0

Shear = 1.0

Timber (8.5.2.2 and .3)

Compression = 0.9

Tension = 0.8

Flexure = 0.85

Shear = 0.75

LRFD

Specifications

Structural Resistance Factors 10.7.3.13 Pile Structural Resistance

36

Field methods

� Static load test

� Dynamic load test (PDA)

� Driving Formulae

� Wave Equation Analysis

Static analysis methods

Determining Nominal Axial Geotechnical

Resistance of Piles

37

Geotechnical Safety Factors for Piles (ASD)

Basis for Design and Type

of Construction Control

Increasing Design/Construction

Control

Subsurface exploration X X X X X

Static analysis X X X X X

Dynamic formula X

Wave equation X X X X

CAPWAP analysis X X

Static load test X X

Factor of Safety (FS) 3.50 2.75 2.25 2.00 1.90

38

Pile Testing Methods

Analysis

Method

Resistance

Factor

(φφφφ) (AASHTO 2010)

Factor of

Safety

(FS)

Estimated Measured

Ca

pa

city

Stress

En

ergy

Ca

pa

city

Stress

En

ergy

Dynamic

formula

0.10 or

0.40 3.50 X

Wave

equation 0.50 2.75 X X X

Dynamic

testing

0.65 or

0.75 2.25 X X X

Static load

test

0.75 to

0.80 2.00 X

39

Geotechnical Nominal Resistance of Piles:

Static Load Tests ASTM D1143 (10.7.8.2)

Test Setup Results and Definition

of Failure

40

Dynamic Load Test (PDA) ASTM D4945 10.7.3.8.3

41

Wave Equation Driven Resistance

10.7.3.8.4

42

Wave Equation Applications

Item Use

Develop driving

criterion

• Blow count for a required nominal

resistance

• Blow count for nominal resistance as a

function of energy/stroke

Check drivability • Blow count vs penetration depth

• Driving stresses vs penetration depth

Determine optimal

driving equipment

• Driving time

Refined matching

analysis

• Adjust input values based on dynamic

measurements

43

68 blows / 0.25 m

GRLWEAP (TM) Version 2003FHWA - GRLWEAP EXAMPLE #1 GRLWEAP (TM) Version 2003FHWA - GRLWEAP EXAMPLE #1

Co

mp

ress

ive

Str

es

s (

MP

a)

0

50

100

150

200

250

Te

ns

ion

Str

es

s (

MP

a)

0

50

100

150

200

250

Blow Count (blows/.25m)

Ulti

ma

te C

ap

ac

ity (

kN

)

0.0 25.0 50.0 75.0 100.0 125.0 150.00

400

800

1200

1600

2000

Blow Count (blows/.25m)

Str

ok

e (

me

ter)

0.0 25.0 50.0 75.0 100.0 125.0 150.00.00

1.00

2.00

3.00

4.00

5.00

DELMAG D 12-42

Efficiency 0.800

Helmet 7.60 kNHammer Cushion 10535 kN/mm

Skin Quake 2.500 mmToe Quake 3.000 mmSkin Damping 0.160 sec/mToe Damping 0.500 sec/m

Pile Length mPile Penetration mPile Top Area cm2

20.00 19.00 86.51

Pile ModelSkin FrictionDistribution

Res. Shaft = 84 %(Proportional)

195 MPa

1480 kN

2.6 m

Wave Equation Results

44

Driving Formulas

(Article 10.7.3.8.5)

45

Pile Testing Methods

Analysis

Method

Resistance

Factor

(φφφφ) (AASHTO 2010)

Estimated Measured

Ca

pa

city

Stress

En

ergy

Ca

pa

city

Stress

En

ergy

Dynamic

formula 0.10 or 0.40 X

Wave

equation 0.50 X X X

Dynamic

testing 0.65 or 0.75 X X X

Static load

test 0.75 to 0.80 X

46

● Calculate pile length for loads

● Determine number of piles

● Determine most cost effective pile type

● Calculate foundation settlement

● Calculate performance under uplift and lateral loads

Static analysis methods and computer solutions

are used to:

47

Static Analysis Methods

• Primary use is for pile length estimation for

contract drawings and feasibility.

• Secondary use for estimation of downdrag,

uplift resistance and scour effects

• Should rarely be used as sole means of

determining pile resistance. ONLY IN SPECIAL

SITUATIONS!

48

Side Resistance

Tip Resistance

Total Resistance

A

B

C D

RP

RS

RR = φRn = φqpRp + φqsRs

Vertical Displacement

Resistance

Large Pile Diameter Resistance

49

Computation of Static Geotechnical Resistance

AASHTO 10.7.3.7.5-2 RP

RS

RR = φRn φRn = φqpRp + φqsRs

RP = AP qP

RS = AS qs

50

Nominal Resistance: Rn = Rs1 + Rs2 + Rs3 +Rt

Factored Resistance: RR = φRn= φ(Rs3 + Rt)

Soil Resistance

to Driving (SRD): SRD = Rs1 + Rs2 + Rs3 +Rt

EXAMPLE SOIL PROFILE

SRD = Rs1 + Rs2 / 2 + Rs3 +Rt

(with clay soil strength change)

((with no soil strength changes)

51

Static Analysis Methods

α method

β method

λ method

Nordlund -Thurman method

SPT-method

CPT-method

Driven Piles

52

Resistance Factors Static Analysis Methods AASHTO Table 10.5.5.2.3-1

Method Resistance Factor, φφφφ

Compression Tension

α- method 0.35 0.25

β- method 0.25 0.20

λ- method 0.40 0.30

Nordlund- Thurman 0.45 0.35

SPT 0.30 0.25

CPT 0.50 0.40

Group 0.60 0.50

53

Combining Geotechnical Resistance Factors

• C10.7.3.3 φdyn x Rn = φ stat x Rnstat

• The length predicted by this method may be

overly conservative and need to be adjusted

to reflect experience.

• Local experience replaces this suggested

relationship.

54

Driven Pile Time Dependent Effects

(Article 10.7.3.4)

Setup Relaxation

RP

RS

RP

RS

RP

RS

RP

RS

55

SOIL SETUP

• Soil setup is a time dependent increase in the static

pile resistance

• Large excess positive pore pressures are often

generated during pile driving

• Soil setup frequently occurs for piles driven in

saturated clays as well as loose to medium dense

silts and fine sands as the excess pore pressure

dissipate

• Magnitude of setup depends on soil characteristics

and pile material and type

56

Point Bearing on Rock

(Article 10.7.3.2)

• Soft rock that can be penetrated by pile driving may be treated similar to soils.

• Steel piles driven into soft rock may not require tip reinforcement.

• On hard rock the nominal resistance is controlled by the structural capacity. See Article 6.9.4.1 and the driving resistances in 6.5.4.2 and 6.15 for severe driving.

• PDA should be used when the nominal resistance exceeds 600 kips.

• C10.7.3.2.3 Provides qualitative guidance to minimize pile damage when driving piles on hard rock.

57

Pile Group Resistance 10.7.3.9 & 11

Static Geotechnical Resistance Figures 10.7.3.11-1 and -2 for group uplift resistance for cohesionless and

cohesive soils respectively.

Take lesser of

58


Topic Slides








59

EXTREME EVENT LIMIT STATES

10.5.5.3

• Scour

• Vessel and Vehicle collision

• Seismic loading and site specific situations.

(Uplift Resistance should be 0.80 rather than

1.00 for all extreme checks.)

60

Piles Subject to Scour

10.5.5.3.2

61

Seismic – Articles 10.7.4, 10.5.5.3.3

• Liquefaction: Neglect axial resistance in

liquefiable zone

• Lateral Spreading: Either consider forces due

to lateral spreading or improve ground;

reduce P-y curve based on duration of strong

shaking and ability of the ground to fully

liquefy during strong shaking

• Downdrag: Do not combine “seismic”

downdrag with “static” downdrag

62


Topic Slides








63

10.7.5 Corrosion and Deterioration

• Identified by soil resistivity & pH testing

• If pH < 4.5, design should be based on an aggressive environment

• Corrosion of steel pile foundations, particularly in fill soils, low pH soils and marine environments

• Sulfate, chloride, and acid attack of concrete pile foundations

• Decay of timber piles from wetting and drying cycles from insects and marine borers

64

Aggressive Subsurface Environments

• Resistivity < 2000 ohms-cm

• pH < 5.5

• pH between 5.5 and 8.5 in soils with high

organic content

• Sulfates > 1,000 ppm

• Landfills and cinder fills

• Soils subject to mine or industrial drainage

• Areas of mixed resistivity (high and low)

• Insects (wood piles)

65

Pile Driving Induced Vibrations

See Hannigan (2006)

• Vibration induced damage

• Vibration induced soil densification

66


Topic Slides








67

Section 10.7.8 Driven Piles

Requirements for

drivability analysis

have been added

and clarified

68

Pile TypePile TypePile TypePile Type Loading TypeLoading TypeLoading TypeLoading Type Limiting Driving StressLimiting Driving StressLimiting Driving StressLimiting Driving Stress

Steel Compression/Tension

Concrete Compression

Tension

Prestressed

Compression

Tension

Tension (in severe corrosion)

Timber Compression/Tension

)9.0( ydadr fφσ =

)f85.0( 'cdadr φ=σ

)f7.0( ydadr φ=σ

)ff85.0( pe'cdadr −φ=σ

)ff095.0( pe'cdadr −φ=σ

)f( pedadr φ=σ

)f( codadr φ=σ

69

Concrete piles, = 1.00

� AASHTO Article 5.5.4.2.1

Steel piles, = 1.00

� AASHTO Article 6.5.4.2

Timber piles, = 1.15

� AASHTO Article 8.5.2.2

Driven Resistance Factors

daφ

daφ

daφ

70


Topic Slides








71

5th Edition 2010 Changes Sec 10.5

• Specification references to changes in resistance factors based on

pile group size moved to the commentary.

• The definition of foundation redundancy (in commentary) was

simplified.

• Tables relating resistance factor to site variability were removed from

the specifications and decisions were deferred to the engineer. The

site variability method was retained as an acceptable option to aid in

engineering judgment.

• Precaution for static analysis predictions for piles greater than 24“

was added.

• The resulting changes based on the above was a modest increase

for several resistance factors.

72

5th Edition 2010 Changes Sec 10.7

• Use of dynamic tests with signal matching to estimate side friction

were added as a reasonable alternative to static analysis methods or

load testing.

• Table 10.7.2.4-1, small adjustments in the p-multipliers for group

lateral load analysis.

• Provisions for piles driven to hard rock (Article 10.7.3.2) were made

more complete.

• Article 10.7.3.3 changed to clarify the use and potential pitfalls of the

approaches provided to estimate the pile length required.

• Article C10.7.3.4.3, guidance added regarding the length of time

needed for various soil conditions before a restrike should be

attempted.

73

Table 10.5.5.2.3-1

Resistance Factors for Driven Piles

• Static Load Test with Dynamic Tests – 0.80 (minimum test number 2 and minimum percentage 2% of tests)

• Static Load Test without Dynamic Tests – 0.75

• Dynamic Testing 100% production piles – 0.75

• Dynamic Tests – 0.65 (minimum test number 2 and

minimum percentage 2% of tests)

• Wave Equation – 0.50

74

For More Information on Driven Piles

75

REFERENCES • Allen, T. M. 2005. “Development of Geotechnical

Resistance Factors and Downdrag Load Factors for LRFD

Foundation Strength Limit State Design”, FHWA-NHI-05-

052, FHWA, Wash. DC.

• Barker, R. M. et al 1991. “Manuals for the Design of Bridge

Foundations” NCHRP Report 343. Transportation Research

Board, NRC, Wash., DC.

• Hannigan P.J. et al, 2005. “Design and Construction of Driven Pile Foundations”, FHWA-HI-05, FHWA, Wash. DC

• Paikowsky S. G. et al, 2004. “Load and Resistance Factor

Design (LRFD) for Deep Foundations”, NCHRP Report

507. Transportation Research Board, NRC, Wash. DC.

76

Practical Implementation of LRFD for

Geotechnical Engineering Features

Design and Construction of Driven Pile Foundations

Wednesday, June 22, 2011

PDCA Professors Workshop

By

Jerry A. DiMaggio, PE, D.GE, M. ASCE

E-Mail: [email protected]

77

practical implementation of lrfd for geotechnical...

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