ASCE 20-96-1997 Standard Guidelines for the Design and Installation of Pile Foundations《桩基础设计和安装标准指南》.pdf

1、SPECIAL NOTICE The material presented in this publication has been prepared in accordance with recognized engineering principles. This Standard and Commentary should not be used without first securing competent advice with respect to their suitability for any given application. The publication of th

2、e material contained herein is not intended as a representation or warranty on the part of the American Society of Civil Engineers, or of any other person named herein, that this information is suitable for any general or particular use or promises freedom from infringement of any patent or patents.

3、 Anyone making use of this information assumes all liability from such use. STD.ASCE 20-ENGL L99b m 0759b00 002.5828 340 m ASCE 20-96 American Society of Civil Engineers Standard Guidelines for the Design and Installation of Pile Foundations STD-ASCE 20-ENGL 177b w 0757b00 0025827 287 ASCE 20-96 Ame

4、rican Society of Civil Engineers Standard Guidelines for the Design and Installation of Pile Foundations Published by American Society ASCE of Civil Engineers 345 East 47th Street New York, NY 1 O01 7-2398 STD-ASCE 20-ENGL L77b = 0757b00 0025830 TT7 = Abstract: This Standard provides a guideline for

5、 an engineering approach to the design and subsequent installation of pile foundations. The purpose is to furnish a rational basis for this process, taking into account published model building codes and general standards of practice. It covers such topics as: i) Administrative requirements; 2) pile

6、 shaft strength requirements; 3) soil-pile interface strength requirements and capacity; 4) design loads; 5) design stresses; 6) construction and layout guidelines for pile design; and 7) installation guidelines for pile construction. In addition, the Standard includes information on applicable stan

7、dards from ASTM, AWPA, and ACI. 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 Society of Civil Engineers. P.

8、cm. 1. Piling (Civil engineering)-Design and construction-Standards. I. Title. TA780.A523 1997 96-30072 624.154-dc21 CIP ISBN 0-7844-02 19- 1 Photocopies. Authorization to photocopy material for internal or personal use under circumstances not falling within the fair use provisions of the Copyright

9、Act is granted by ASCE to libraries and other users registered with the Copyright Clearance Center (CCC) Transactional Reporting Service, provided that the base fee of $4.00 per article plus $.50 per page is paid directly to CCC, 222 Rosewood, Drive, Danvers, MA 01923. The identification for ASCE Bo

10、oks is O-7844-0219-1/97/$4.00 + $SO per page. Requests for special permission or bulk copying should be addressed to Permissions also called down-drag load. Pile Cushion: Material, most commonly plywood, placed on top of a precast concrete pile to control compressive and tensile stresses in the pile

11、 during driving; to distribute the force of the hammer blow uniformly over the top of the pile; and to compen- sate for surface irregularities at the top surface of the pile. Static Analysis: Analysis of the supporting capacity of the pile-soil system employing rele- vant soil and/or rock strength p

12、arameters and prop- erties along with established interaction correla- tions between the pile shaft and the soilhock materials. Service Load (Design Load): The maximum com- pressive, tensile, or lateral load, or combination thereof, considered to act on the pile during the life of the structure. Set

13、tlement (Load Test): Gross settlement is the total downward movement of a pile that occurs under an applied test load. Net settlement is gross settlement minus the rebound that occurs after removal of the applied test load. Supporting Materials: The layer or layers of soil or rock that provide princ

14、ipal support to the pile. ultimate Load (Capacity): The load at which the pile failure first occurs due to exceeding the struc- tural strength of the shaft, or the ultimate resistance of the supporting materials. Wave Equation Analysis: A rational computer- based method of analysis of the interactio

15、n of the hammer, pile, and soil, based on one-dimensional elastic wave propagation principles. Working Load (Design Load): The maximum compressive, tensile, or lateral load, or combination thereof, considered to act on the pile during the life of the structure. 2 STD-ASCE 20-ENGL L77b 0757b00 002583

16、7 L2b STANDARD GUIDELINES FOR THE DESIGN AND INSTALLATION OF PILE FONDATIONS CHAPTER 2 Administrative Requirements 2.1 Investigation for Design analysis of the site and subsurface conditions should be conducted, under the supervision of a Geotechni- cal Engineer, to provide the basis for the design

17、and installation of foundation piles. Borings, test pits, cone probes, subsurface sampling, field and labora- tory tests, or in the sole judgement of the Engineer, other data including information from adjacent sites, previous construction or engineering, and other sources of site information may be

18、 used to identify appropriate geotechnical design criteria, or to con- firm design and installation criteria previously obtained. All such information should be identified and maintained in the project files. A foundation investigation and engineering 2.2 Design Analysis other available data should

19、then be used by the Engineer to prepare the pile foundation design analysis. The design analysis should include consid- eration of the loading conditions, environment, structure deformation tolerances, anticipated bearing strata, acceptable methods of pile instailation, suit- able pile types, and th

20、e character and performance of previous or existing construction at the site or adjacent sites. The Engineer should then prepare a design for the pile foundation with appropriate margins of safety against (1) failure of the earth materials, and (2) against over-stressing of the pile shaft as require

21、d by this Standard. The foundation design should be consistent with the deformation tolerances of the structure. The pile type, design load, pile capacity, estimated pile lengths, and installation cri- teria are integral parts of the foundation design. The results of the subsurface investigation and

22、/or 2.3 Durability Piles may deteriorate due to biological, chemical, and physical actions caused by particular site condi- tions. Therefore the Engineer should evaluate possi- ble deleterious actions on pile materials that limit the life of the pile or reduce its structural capacity. The pile desig

23、n should show a reasonable expecta- tion of the shaft structural strength required by this Standard for the expected life of the supported structure, or provisions should be made for pile pro- tection, or for any subsequent replacement that may be required. For piles that extend above the ground sur

24、face or through open water, special consideration should be given to the possible effect of environ- mental conditions on the pile material. Appropriate measures should be taken to safeguard the founda- tion from deterioration due to conditions such as atmospheric corrosion, sea water exposure, ther

25、mal stresses, and freeze-thaw cycles. 2.4 Adjacent Property installation on existing underground structures, including utilities, and excavations, and on adjacent structures and property, and, as necessary, should incorporate suitable protective requirements in the project contract documents. The En

26、gineer should evaluate the effects of pile 2.5 Use of Existing Piles Existing piles may be used to support new con- struction provided that, prior to the new construc- tion, the Engineer determines that there is satisfac- tory evidence that the piles are sound and will support the intended loads. Su

27、ch evidence should include one or more of the following. (1) Documentation of the loading and concur- rent satisfactory performance of the previ- ous foundation; (2) representative load testing; (3) pile re-driving; (4) dynamic measurement and analysis; (5) static analysis; (6) a subsurface investig

28、ation to identify repre- sentative conditions that provide support to the piles; and as dictated by project requirements. (7) other information, exploration, and testing 2.6 Special Design Considerations Piles should be designed and installed to allow for exposure, appropriate unsupported length, sc

29、our, and lateral loading, without unacceptably reducing the load-carrying capacity or lateral stability of the piles. 2.7 Coordination with Other Work between pile installation operations and other site operations, including but not limited to, excava- The design should take into account coordinatio

30、n 3 STD*ASCE 20-ENGL L77b W 0757b00 0025840 948 STANDARD GUIDELINES FOR THE DESIGN AND INSTALLATION OF PILE FOUNDATIONS tions, shoring and bracing, dewatering, slope stabil- ity, underpinning, and any other pertinent opera- tions. If specific procedures and orders of operations are required, these s

31、hould be specified in the design. 2.8 Installation Criteria The Engineer should document the design crite- ria and driving or installation criteria to be applied to the project or to each pile or pile group. The final installation criteria, as modified by any tests, probe pile installation, field co

32、nditions, or any other rea- sons should be documented. These installation crite- ria should include minimum hammer energies, driving resistances, minimum auger torques and energies, minimum rates of pumping, maximum rates of auger withdrawal, penetration rates, pene- tration lengths, minimum tip ele

33、vations, combina- tions of these criteria, or other specific equipment, material, or procedural requirements. 2.9 Plans and Specifications required submittals, the plans and specifications should show, or include, the following: In addition to any other specific building code Location of each pile,

34、relative to permanent reference. Unique designation or number for each pile. Pile cut-off elevation. Minimum pile tip elevation for each area of generally similar soil conditions, if appropriate. Required inclination and direction of incli- nation. Required orientation of nonround piles, if applicab

35、le. Note: It is not normally considered good practice to attempt to restrain the pile so as to prevent rotation or other movements that may occur during installation due to under- ground conditions. Pile design loads and factors of safety. Logs, location, and elevations of soil bor- ings relative to

36、 the pile location reference system. Pile testing and inspection requirements. Pile installation criteria. Pile reinforcing, and any attachment or anchor details. Engineer, or a representative designated by the Engineer. Records should confirm that the final pile installation criteria, including any

37、 modifications, are in accordance with Sec. 8.16 of this Standard. These observations and documentation should include complete information on any pile testing, equip- ment, and installation operations. The Engineer should retain copies of installation records as long as legally required, but no les

38、s than one year after essential completion of the structure. 2.11 Design Modifications Design modifications caused by changed or unanticipated field conditions should be docu- mented by the Engineer, and such modifications should meet the applicable design requirements of this Standard. 2.12 Load Te

39、sts If load tests are performed or required, tests should be in accordance with Sec. 4.5 of this Standard. The Engineer or his or her representative should specify, observe, and document details of each pile load test. CHAPTER 3 Pile Shaft Strength Requirements 3.1 General Pile design involves separ

40、ate strength require- ments: (1) the strength of the pile shaft, and (2) the strength of the earth materials at the soil-pile inter- face along the pile shaft as well as at, and below, the pile tip (Sec. 4.0). 3.1.1 Minimum piie shaft material require- ments. Unless otherwise specified, the minimum

41、pile shaft strength provisions detailed in this section (Sec. 3.0) should apply. 2.10 Records tions should be observed and documented by the 3.2 Structurai Strength of piles The overall structural stresses under the design load occurring in the installed pile shaft should be The installation and con

42、struction of pile founda- 4 STD.ASCE 20-ENGL L77b 0757b00 002584L 884 STANDARD GUIDELMES equal to or less than those allowed by local codes or this Standard. The design loads should include axial compression or tension, combined with moment or shear. In determining the necessary structural strength

43、of a pile, consideration should be given to material strength reductions that may occur as a result of the variability of material properties, accidental eccentricity of the applied load, pile mislocation, and deviation of the installed pile cross-section from the shape and dimension specified. The

44、effect of lateral loads, not resisted by inclined piles or other structural elements, should be evaluated during pile design. The Engineer should design the pile based upon a determination of the lateral deflection of the pile head and distribution of resulting moment and shear along the pile shaft,

45、 using a method of analysis that takes into account pile-soil elastic interaction, load duration, load rep- etition, structural restraint at the pile head, and the effect of group action. 3.2.1 Maximum allowable shaft stresses. Provisions for maximum allowable stresses at design loads are provided b

46、y material and pile type in Sec. 6.0. 3.3 Critical Shaft Section The Engineer should analyze the distribution of loads along the pile shaft and design for sufficient strength at all locations. Determination of the criti- cal section is essential for tapered or other nonuni- form piles. 3.4 Handling

47、and Driving Stresses Piles should be designed to be of sufficient size and strength so that detrimental yielding, cracking, or failure of the pile does not occur during trans- portation, lifting, or driving. The design should consider: (1) the maximum stresses induced during han- (2) the pile length

48、s that may be required, and (3) the compatibility of the driving equipment dling and driving, and pile material, with the soilhock sub- surface conditions. 3.5 Piles with Unsupported Length Piles or portions thereof located in air, water, or soil not providing lateral support, should be designed in

49、accordance with accepted engineering practice for both unsupported column and exposure conditions. FOR THE DESIGN AND INSTALLATION OF PILE FOUNDATIONS CHAPTER 4 Soil-Pile Interface Strength Requirements and Capacity 4.1 General Pile design involves separate strength require- ments: (1) the strength of the pile shaft, (Sec. 3.0), and (2) the strength of the earth materials at the soil-pile interface along the pile shaft as well as at, and below, the pile tip (Sec. 4.0). 4.1.1 Analysis of soil- pile capacity. Evaluation of the capacity of a single pile should be performed using load tests,