ASCE 7-10 SEISMIC LOADS-2015 Seismic Loads Guide to the Seism ic Load Provisions of ASCE 7-10.pdf

1、 Seismic Loads Minimum Design Loads for Buildings and Other Structures, ASCE/SEI 7-10 (ASCE, 2013): Provides requirements for general structural design and includes means for determining dead, live, soil, ood, snow, rain, atmo- spheric ice, earthquake, and wind loads, as well as their combinations,

2、which are suitable for inclusion in building codes and other documents. Includes a detailed commentary with explanatory and supplementary information. B o oks Rela ted to ASCE 7-10 Signi cant Changes to the Seismic Load Provisions of ASCE 7-10: An Illustrated Guide by S.K. Ghosh, Ph.D.; Susan Dowty,

3、 P.E.; and Prabuddha Dasgupta, Ph.D., P.E. (ASCE, 2010): Summarizes changes to the seismic provisions of ASCE 7-10 that might affect actual practice or enforcement, including the precise wording of the change. Signi cant Changes to the Wind Load Provisions of ASCE 7-10: An Illus- trated Guide by T.

4、Eric Stafford, P.E. (ASCE, 2010): Translates changes to the wind load provisions of ASCE 7-10 into a form readily accessible by structural engineers, architects, contractors, building of cials and inspectors, and allied professionals. Snow Loads: Guide to the Snow Load Provisions of ASCE 7-10 by Mic

5、hael O Rourke, Ph.D., P.E. (ASCE, 2010): Illustrates key concepts and guides for applying the provisions of ASCE 7-10 to the design of new and existing structures that could collect falling or drifting snow. Wind Loads: Guide to the Wind Load Provisions of ASCE 7-10 by Kishor C. Mehta, Ph.D., P .E.,

6、 and William Coulbourne, P .E. (ASCE, 2013): Explains the wind load provisions of ASCE/SEI 7-10 as they affect the planning, design, and construction of buildings for residential and commercial purposes. Books on Seismic Engineering Earthquake Protection of Building Equipment and Systems: Bridging t

7、he Implementation Gap by Jeffrey A. Gatscher, Gary L. McGavin, and Philip J. Caldwell (ASCE, 2012): Offers a framework for applying the latest earth- quake engineering research to the nonstructural elements of individual build- ing projects, concentrating on mechanical and electrical systems. Earthq

8、uakes and Engineers: An International History by Robert K. Reither- man (ASCE, 2012): Traces the evolution of humankind s understanding of the causes and characteristics of earthquakes and the development of methods to design structures that resist seismic shocks. Guidelines for Seismic Evaluation a

9、nd Design of Petrochemical Facilities by the Task Committee on Seismic Evaluation and Design of Petrochemical Facilities (ASCE, 2011): Presents practical recommendations regarding the design and safety of petrochemical facilities during and after an earthquake, including guidance on design details a

10、nd considerations that are not included in building codes. Seismic Evaluation and Retro t of Existing Buildings, ASCE/SEI 41-13 (ASCE, 2014): Describes de ciency-based and systematic procedures that use performance-based principles to evaluate and retro t existing buildings to withstand the effects

11、of earthquakes. Other Titles of Interest Seismic Loads Guide t o the Seism ic Load Provisions of A SCE 7-10 Finley A. Charney , Ph.D., P.E., F.ASCE, F.SEI Library of Congress Cataloging-in-Publication Data Charney, Finley Allan. Seismic loads (2014) Seismic loads : guide to the seismic load provisio

12、ns of ASCE 7-10 / Finley A. Charney, Ph.D., P.E. pages cm Includes bibliographical references and index. ISBN 978-0-7844-1352-4 (soft cover) ISBN 978-0-7844-7839-4 (e-book pdf) 1. Earthquake resistant designStandards. 2. Earthquake resistant design Case studies. I. Title. TA658.44.C3824 2014 624.1 7

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19、/10.1061/9780784413524 Copyright 2015 by the American Society of Civil Engineers. All Rights Reserved. ISBN 978-0-7844-1352-4 (paper) ISBN 978-0-7844-7839-4 (e-book PDF) Manufactured in the United States of America. 21 20 19 18 17 16 15 1 2 3 4 5 Seismic Loads: Guide to the Seismic Load Provisions o

20、f ASCE 7-10 v Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Abbreviations and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Table of Conversion Factors . . . . . . . . . . . . . . . . . .

21、. . . . . . . . . . . . . . . xiii Examples 1. Risk Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Importance Factor and Seismic Design Category . . . . . . . . . . . . . . . 7 3. Site Classi cation Procedure for Seismic Design . . . . . . . . . . .

22、 . . . . 11 4. Determining Ground Motion Parameters . . . . . . . . . . . . . . . . . . . . 19 5. Developing an Elastic Response Spectrum . . . . . . . . . . . . . . . . . . . 25 6. Ground Motion Scaling for Response History Analysis . . . . . . . . . 29 7. Selection of Structural Systems . . . . .

23、. . . . . . . . . . . . . . . . . . . . . . . 37 8. Combinations of Lateral Load-Resisting Systems . . . . . . . . . . . . . . 45 9. Horizontal Structural Irregularities . . . . . . . . . . . . . . . . . . . . . . . . . 53 10. Vertical Structural Irregularities . . . . . . . . . . . . . . . . . . .

24、. . . . . . . . 63 11. Diaphragm Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 12. Structural Analysis Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . 79 13. Use of the Redundancy Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

25、3 14. Accidental Torsion and Ampli cation of Accidental Torsion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 15. Load Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 16. Effective Seismic Weight (Mass) . . . . . . . . . . . .

26、 . . . . . . . . . . . . . . 105 17. Period of Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 18. Equivalent Lateral Force Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 123 19. Drift and P-Delta Effects . . . . . . . . . . . . . . . . . . . . . . .

27、 . . . . . . . . . 135 20. Modal Response Spectrum Analysis . . . . . . . . . . . . . . . . . . . . . . . 147 21. Modal Response History Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 165 22. Diaphragm Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 F

28、requently Asked Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185vi Seismic Loads: Guide to the Seismic Load Provisions of ASCE 7-10 Appendices A. Interpolation Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 B. Using the USGS Seismic H

29、azards Mapping Utility . . . . . . . . . . . . . 205 C. Using the PEER NGA Ground Motion Database . . . . . . . . . . . . . . 211 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30、 . . . . . . . . . . . . . . . . . . . . . . . 219 About the Author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 Seismic Loads: Guide to the Seismic Load Provisions of ASCE 7-10 viiPr ef ace The purpose of this guide is to provide examples related to the use

31、of the Standard ASCE/SEI 7-10, Minimum Design Loads for Buildings and Other Structures (often referred to as ASCE 7). The guide is also pertinent to users of the 2012 International Building Code (ICC, 2011 ) because the IBC refers directly to ASCE 7. Sections of ASCE 7 Pertinent to the Guide Seismic

32、 Loads: Guide to the Seismic Load Provisions of ASCE 7-10 (the Guide ) has examples pertinent to the following chapters of ASCE 7:Chapter 1: General Chapter 2: Combinations of Loads Chapter 11: Seismic Design Criteria Chapter 12: Seismic Design Requirements for Building Structures Chapter 16: Seismi

33、c Response History Procedures Chapter 20: Site Classi cation Procedure for Seismic Design Chapter 22: Seismic Ground Motion and Long Period Maps Seismic material excluded from the Guide are Chapter 13 (Nonstruc- tural Components), Chapter 14 (Material-Speci c Design and Detailing Requirements), Chap

34、ter 15 (Nonbuilding structures), Chapter 17 (Seismic Design Requirements for Seismically Isolated Structures), Chapter 18 (Seismic Design Requirements for Structures with Damping Systems), Chapter 19 (Soil-Structure Interaction for Seismic Design), and Chapter 21 (Site-Speci c Procedures for Seismic

35、 Design). The vast majority of the examples in the Guide relate to Chapters 1, 2, 11, 12, and 16 of ASCE 7, with buildings as the principal subject. The materials on nonstructural components and on nonbuilding structures will be expanded in a later edition of the Guide , or in a separate volume. The

36、 materials presented for Chapter 16 relate to the selection and scaling of ground motions for response history analysis and the use of linear response history analysis. Chapter 14 of ASCE 7 is not included because the Guide focuses prin- cipally on seismic load analysis and not seismic design. The r

37、eader is referred to the Reference section of the Guide for resources containing design exam- ples. The materials included in Chapters 17 through 19 are considered “advanced topics” and may be included in a future volume of examples. The principal purpose of the Guide is to illustrate the provisions

38、 of ASCE 7 and not to provide background on the theoretical basis of the provi- sions. Hence, theoretical discussion is kept to a minimum. However, expla- nations are provided in a few instances. The reference section contains viii Seismic Loads: Guide to the Seismic Load Provisions of ASCE 7-10 sev

39、eral sources for understanding the theoretical basis of the ASCE 7 seismic loading provisions. Speci cally, the reader is referred to the expanded com- mentary to the ASCE Seismic Provisions. Note that this commentary was rst available in the third printing of ASCE 7. Additional useful documents pro

40、vided by FEMA (at no charge) are as follows:FEMA P-749, “Earthquake Resistant Design Concepts” (FEMA, 2010 ); FEMA P-750, “NEHRP Recommended Seismic Provisions for New Buildings and Other Structures” (FEMA, 2009a ); and FEMA P-751, “NEHRP Recommended Provisions: Design Exam- ples” (FEMA, 2012 ). FEM

41、A P-751 contains numerous detailed design examples that incor- porate many of the requirements of ASCE 7-05 and ASCE 7-10. These examples are much more detailed than those provided in this Guide and concentrate on the structural design aspects of earthquake engineering, rather than just the loads an

42、d analysis side, which is the focus of the Guide . The National Institute of Building Standards (NIST) provides another excellent set of seismic analysis and design references. These “technical briefs” cover various subjects, including diaphragm behavior, design of moment frames, design of braced fr

43、ames, and nonlinear structural analysis. The briefs can be downloaded at no charge from www.nehrp-consultants .org. How to Use the Guide The Guide is organized into a series of individual examples. With minor exceptions, each example “stands alone” and does not depend on informa- tion provided in ot

44、her examples. This means that, in some cases, information is provided in the beginning of the example that requires some substantial calculations, but these calculations are not shown. For instance, in the example on drift and P-delta effects (Example 19), the details for computing the lateral force

45、s used in the analysis are not provided, and insuf cient information is provided for the reader to back-calculate these forces. However, reference is made to other examples in the Guide where similar calculations (e.g., nding lateral forces) are presented. The reader should always be able to follow

46、and reproduce all new numbers (not part of the given information) that are generated in the example. T able and F igur e Numbering The examples presented in the Guide often refer to sections, equations, tables, and gures in ASCE 7. All such items are referred to directly, without speci c reference t

47、o ASCE 7. For instance, a speci c example might contain the statement, “The response modi cation factor R for the system is pro- vided by Table 12.2-1.” References to sections, equations, tables, and gures that are unique to the Guide are always preceded by the letter G and use bold text. For exampl

48、e, Seismic Loads: Guide to the Seismic Load Provisions of ASCE 7-10 ix the text may state that the distribution of forces along the height of the struc- ture are listed in Table G12-3 and illustrated in Fig. G12-5 . In this citation, the number 12 is the example number, and the number after the dash

49、 is the sequence number of the item (that is, third table or fth gure). Nota tion and De nitions The mathematical notation in the Guide follows directly the notation pro- vided in Chapter 11 of ASCE 7. However, as the Guide does not use all of the symbols in ASCE 7, a separate list of symbols actually used in the Guide is provided in a separate section titled “Symbols Unique to the Guide. ” This list also provides de nitions for new symbols that have been introduced in the Guide . C omputa tional Units All examples in the Gui