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ASCE 20-96

American Society of Civil Engineers

Standard Guidelines for theDesign and Installation of

Pile Foundations

Published byAmerican Societyof Civil Engineers

1801 Alexander Bell DriveReston, Virginia 20191-4400



Abstract:

This Standard provides a guideline for an engineering approach to the design and subsequentinstallation of pile foundations. The purpose is to furnish a rational basis for this process, takinginto account published model building codes and general standards of practice. It covers suchtopics as: 1) Administrative requirements; 2) pile shaft strength requirements; 3) soil-pileinterface strength requirements and capacity; 4) design loads; 5) design stresses; 6) constructionand layout guidelines for pile design; and 7) installation guidelines for pile construction. Inaddition, the Standard includes information on applicable standards from ASTM, AWPA, andACL It concludes with an Appendix on partial factors of safety.

Library of Congress Cataloging-in-Publication Data

American Society of Civil Engineers.Standard guidelines for the design and installation of pile foundations / ASCE, American Societyof Civil Engineers.p. cm.ISBN 0-7844-0219-11. Piling (Civil engineering)~Design and construction—Standards.I. Title.TA780.A523 1997 96-30072624.1'54-dc21 CIP

Photocopies. Authorization to photocopy material for internal or personal use undercircumstances not falling within the fair use provisions of the Copyright Act is granted by ASCEto libraries and other users registered with the Copyright Clearance Center (CCC) TransactionalReporting Service, provided that the base fee of $4.00 per article plus $.50 per page is paiddirectly to CCC, 222 Rosewood, Drive, Danvers, MA 01923. The identification for ASCEBooks is 0-7844-0219-l/97/$4.00 + $.50 per page. Requests for special permission or bulkcopying should be addressed to Permissions & Copyright Dept, ASCE.

Copyright © 1997 by the American Society of Civil Engineers,All Rights Reserved.Library of Congress Catalog Card No: 96-30072ISBN 0-7844-0219-1Manufactured in the United States of America.



STANDARDSIn April 1980, the Board of Direction approved

ASCE Rules for Standards Committees to governthe writing and maintenance of standards devel-oped by the Society. All such standards are devel-oped by a consensus standards process managed bythe Management Goup F (MGF), Codes andStandards. The consensus process includes ballotingby the balanced standards committee made up ofSociety members and non-members, balloting bythe membership of ASCE as a whole and ballotingby the public. All standards are updated or reaf-firmed by the same process at intervals not exceed-ing five years.

The following standards have been issued:

ANSI/ASCE 1-82 N-725 Guidelines for Designand Analysis of Nuclear Safety Related EarthStructures

ANSI/ASCE 2-91 Measurement of Oxygen Transferin Clean Water

ANSI/ASCE 3-91 Standard for the StructuralDesign of Composite Slabs and ANSE/ASCE 9-91 Standard Practice for the Construction andInspection of Composite Slabs

ASCE 4-86 Seismic Analysis of Safety-RelatedNuclear Structures

Building Code Requirements for Masonry Struc-tures (ACI530-95/ASCE5-95/TMS402-95) and

Specifications for Masonry Structures (ACI530.1-95/ASCE6-95/TMS602-95)

Specifications for Masonry Structures (ACI530-95/ASCE6-95/TMS602-95)

ANSI/ASCE 7-95 Minimum Design Loads forBuilding and Other Structures

ANSI/ASCE 8-90 Standard Specification for theDesign of Cold-Formed Stainless Steel StructuralMembers

ANSI/ASCE 9-91 listed with ASCE 3-91ANSI/ASCE 10-90 Design of Latticed Steel

Transmission StructuresANSI/ASCE 11-90 Guideline for Structural

Condition Assessment of Existing BuildingsANSI/ASCE 12-91 Guideline for the Design of

Urban Subsurface DrainageASCE 13-93 Standard Guidelines for Installation of

Urban Subsurface DrainageASCE 14-93 Standard Guidelines for Operation and

Maintenance of Urban Subsurface DrainageANSI/ASCE 15-93 Standard Practice for Direct

Design of Buried Precast Concrete Pipe UsingStandard Installations (SIDD)

ASCE 16-95 Standard for Load and ResistanceFactor Design (LRFD) of Engineered WoodConstruction

ASCE 20-96 Standard Guidelines for the Designand Installation of Pile Foundations

ASCE 21-96 Automated People MoverStandards-Part 1

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FOREWORDPiles differ from most other portions of a struc-

ture in that with few exceptions they are not able tobe visually inspected after installation. Driven pilesare generally subjected to considerable stress duringinstallation. For both driven and drilled piles, thepotential for the pile shaft to sustain damage duringinstallation should be considered in the determina-tion of minimum dimensions and maximum designstresses. Furthermore, consistently identifiable soilstrength parameters, coupled with consistent or uni-form bearing strata are generally not luxuries foundin foundation design.

This Standard provides a guideline for an engi-neering approach to the design and subsequentinstallation of pile foundations. The purpose is toprovide a rational basis for this process, taking into

account published model building codes and generalstandards of practice. It is intended for use by pro-fessional personnel of sufficient competency toevaluate the essence and limitations of the provi-sions contained herein and who will accept theresponsibility for the application of the material pre-sented.

In general, the expertise required to properlyimplement this Standard is seldom found in oneindividual. A common design team includes both astructural engineer and a geotechnical engineer, andmay in addition include a pile contractor to provideconstruction expertise and cost estimates.Communication among all members of the designteam and the client will aid in the successful imple-mentation of this Standard.

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ACKNOWLEDGMENTSThe American Society of Civil Engineers (ASCE)

acknowledges the work of the Pile FoundationsStandards Committee of the Codes and StandardsActivities Committee (CSAC). This group comprisesindividuals from many backgrounds including: con-sulting engineering, research, the construction indus-try, design, and private practice.

These Standard Guidelines were preparedthrough the consensus standards process by ballot-ing in compliance with procedures of ASCE'sCodes and Standards Activities Committee (CSAC).Those individuals who serve on the StandardsCommittee are:

Carroll L. Crowther, ChairmanGirish AgrawalJames E. BarrisJames C. Benton, Jr.Edward Demsky

Thomas D. DismukeMichael F. EngestromC. Scott FletcherFrank GaaschJames S. GrahamAhmad HabibianJoseph C. HardenSteven W. HuntMohamad H. HusseinBarry A. JohnsonMichael L. JonesJai KimRobert G. LukasDaniel M. McGeeCetin A. OkcuogluRobert F. Pierry, Jr.Abdulreza A. SadjadiJerry A. StedingYuanhui Sun

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Standard Guidelines for the Designand Installation of Pile Foundations

Contents PAGEFOREWORD vSTANDARDS Hi

ACKNOWLEDGMENTS vii

1 GENERAL 11.1 Scope 11.2 Referenced Standards 11.3 Deviations from This Standard 11.4 Engineer Required 11.5 Definitions 1

2 ADMINISTRATIVE REQUIREMENTS 32.1 Investigation for Design 32.2 Design Analysis 32.3 Durability 32.4 Adjacent Property 32.5 Use of Existing Piles 32.6 Special Design Considerations 32.7 Coordination with Other Work 32.8 Installation Criteria 42.9 Plans and Specifications 42.10 Records 42.11 Design Modifications 42.12 Load Tests 4

3 PILE SHAFT STRENGTH REQUIREMENTS 73.1 General 4

3.1.1 Minimum pile shaft material requirements 43.2 Structural Strength of Piles 4

3.2.1 Maximum allowable shaft stresses 53.3 Critical Shaft Section 53.4 Handling and Driving Stresses 53.5 Piles with Unsupported Length 5

4 SOIL-PILE INTERFACE STRENGTH REQUIREMENTS AND CAPACITY 54.1 General 5

4.1.1 Analysis of soil-pile capacity 54.2 Designation of Supporting Strata 5

4.2.1 Ultimate capacity 54.2.2 Pile groups 5

4.3 Static Resistance Analysis 64.3.1 Pile movement under load 6

4.4 Negative Friction 64.5 Pile Load Tests 6

4.5.1 Design capacity by load tests 64.5.2 Dynamic testing 64.5.3 Static load tests 7

4.5.3.1 Static compressive load tests 74.5.3.2 Static tensile load tests 7

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STANDARD GUIDELINES FOR THE DESIGN AND INSTALLATION OF PILE FOUNDATIONS

4.5.3.3 Static lateral load tests 74.5.3.4 Time of load tests 74.5.3.5 Interpretation of static pile load tests 7

5 DESIGN LOADS 85.1 Loads To Be Used 85.2 Maximum Combination of Loads 85.3 Pile Groups 8

6 DESIGN STRESSES 96.1 General 9

6.1.1 Use of higher allowable stresses 96.2 Timber Piles 9

6.2.1 Dimensions and stresses 96.2.2 Preservative treatment 96.2.3 Untreated timber piles 9

6.3 Concrete Piles 96.3.1 Reinforced precast concrete piles 96.3.2 Prestressed precast concrete piles 96.3.3 Concrete-filled shell piles 106.3.4 Uncased cast-in-place and augered pressure grouted concrete piles 106.3.5 Enlarged base piles 10

6.4 Steel Piles 106.4.1 Allowable stresses 106.4.2 Minimum dimensions, rolled steel H piles, and fabricated piles 106.4.3 Minimum dimensions, steel pipe piles 116.4.4 Steel pipe or tube piles—concrete filled 116.4.5 Mandrel-driven shell or tube piles 116.4.6 Driven caisson-type piles 116.4.7 Composite and other pile types 11

6.5 Mini-Piles 126.5.1 Mini-pile strength requirements and capacity 126.5.2 Mini-pile quality control 12

7 CONSTRUCTION AND LAYOUT GUIDELINES FOR PILE DESIGN 127.1 General 127.2 Deviation 127.3 Driving Stresses 127.4 Location and Axial Alignment Tolerances 137.5 Obstructions and Hard Strata 137.6 Design Modifications Due to Field Conditions 137.7 Cross-Sectional Area 137.8 Pile Spacing 137.9 Caps and Bracing 147.10 Splices 147.11 Multiple Pile Types, Capacities, or Methods of Installation 14

8 INSTALLATION GUIDELINES FOR PILE CONSTRUCTION 158.1 General 158.2 Installation Equipment 15

8.2.1 Selection of driving system 158.2.2 Followers 15

8.3 Equipment for Augered Pressure Grouted Piles 158.3.1 Augering equipment 15

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STANDARD GUIDELINES FOR THE DESIGN AND INSTALLATION OF PILE FOUNDATIONS

8.3.2 Mixing and pumping equipment 158.4 Operations 158.5 Continuous Driving 168.6 Pre-Excavation 168.7 Heaved Piles 168.8 Installation Sequence 168.9 Cast-in-Place Concrete 178.10 Driving and Installation Anomalies 178.11 Relaxation 178.12 Soil Freeze or Setup 178.13 Obstructions 178.14 Pile Protection 178.15 Bent, Dog-Legged, or Collapsed Piles 188.16 Pile Installation and Testing Records 188.17 Probe Piles 18

9 APPLICABLE STANDARDS 189.1 ASTM Standards 189.2 AWPA Standards 209.3 ACI Standards 20

APPENDIX A PARTIAL FACTORS OF SAFETY 21A.I Introduction 21A.2 Application 23A.3 Commentary on Appendix A 24

A.3.1 Factor F, 24A.3.2 Factor F, 25

INDEX 26

XI



CHAPTER 1

General

1.1 ScopeThe provisions of this Standard establish guide-

lines for the design and construction of pile founda-tions. Many of the design considerations containedherein require a working knowledge of soil mechan-ics and foundation engineering. Such knowledge isnecessary for the design part of this Standard.

1.2 Referenced StandardsIn addition to local codes and ordinances having

jurisdiction, the provisions of the Referenced Stan-dards, Sec. 9 of this Standard should be consideredwhere they apply and where noted.

1.3 Deviations from This StandardDeviations from the requirements of this Stan-

dard Guideline should be permitted only under theconditions stated in Sec. 6.1.1 and 6.4.7. Use of pro-prietary, new and/or improved pile types, materials,evaluation techniques, and pile installation tech-niques are not prohibited, as long as the design andinstallation of the piles are shown to comply withthese guidelines.

1.4 Engineer RequiredAll work covered by this Standard should be

under the direction of a professional engineer(1) having current experience and qualifications inpile foundation design, construction, and under-standing verification techniques as dictated by theproject requirements, and (2) having a valid profes-sional engineering license in the locality where thepiles are to be installed. This professional engineeris hereinafter referred to as the Engineer. TheEngineer may delegate portions of the exploration,design, testing, and inspection to qualified person-nel, working under his or her direction, where per-mitted by local law.

1.5 DefinitionsThe following terms are defined with reference

to the work covered by this Standard. Terms in theStandard that are not defined shall have their ordi-narily accepted meanings within the context with

which they are used. Webster's New InternationalDictionary of English Language, Unabridged, latestedition, shall be considered as providing ordinarilyaccepted meanings.

Acceptable or Accepted: Meets with the approvalof the Engineer or Geotechnical Engineer.Documentation of such approval usually constitutesacceptance or approval.

Accepted (Engineering) Practice: The practice ofCivil Engineering that conforms to principles, tests,and standards of care and skill ordinarily applied byqualified civil engineering professionals.

Augered Pressure Grouted Pile (APGP): A cast-in-place concrete pile made by rotating a continu-ous-flight, hollow shaft auger into the ground to aspecific depth, or until other specified criteria arereached. Grout is then injected through the augershaft in such a way as to exert pressure on thesoil surrounding the augered hole as the auger iswithdrawn.

Building Official: The official or his or her dulyauthorized representative or other designatedauthority charged with the administration andenforcement of the building code.

Cast-in-Place: Concrete placed into a pile shaft atthe site during, or after, installation of the pile.

Capacity (Ultimate Load): The load at which thepile failure first occurs due to exceeding the struc-tural strength of the shaft, or the ultimate resistanceof the supporting materials.

Critical Section: The cross-section of a pile shaftwhere the maximum stresses occur.

Cut-off Elevation: The elevation at the top of pile(also called the head or butt) as shown in plans andspecifications.

Current Experience: Experience within the lastfive years utilizing design, testing, and installationtechniques applicable to the current project.

Design Load: The maximum compressive, tensile,or lateral load, or combination thereof, consideredto act on the pile during the life of the structure.

Design Stress: The stress imposed on the pilecross-section by the design load and calculated inaccordance with accepted engineering practice.

Drive Head (Drive Cap, Anvil, or Helmet): A steelcasting or forging generally shaped to fit the pile-driving hammer base to the pile, so as to uniformlydistribute the hammer blows to the top of the pile.

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