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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
×
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Suggested Citation:"APPENDIX B Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2012. Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions. Washington, DC: The National Academies Press. doi: 10.17226/14660.
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Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

37 Pyke, R.M., H.B. Seed, and C.K. Chan, "Settlement of Sands mological Society of America, Vol. 90, 6 Suppl., 2000, pp. under Multidirectional Shaking," Journal of Geotechni- S149­S169. cal Engineering Division, Vol. 101, No. GT4, 1975, pp. Stewart, J. and A.O.L. Kwok, "Nonlinear Seismic Ground 379­398. Response Analysis: Code Usage Protocols and Verifica- Rathje, E.M., N.A. Abrahamson, and J.D. Bray, "Simplified tion Against Vertical Array Data," Geotechnical Earth- Frequency Content Estimates of Earthquake Ground quake Engineering and Soil Dynamics IV Congress Motions," Journal of Geotechnical & Geoenvironmental 2008--Geotechnical Earthquake Engineering and Soil Engineering, Vol. 124, No. 2, 1998, pp. 150­159. Dynamics, GSP 181. Rathje, E.M., A.R. Kottke, and W.L. Trent, "Influence of Streeter, V.L., E.B. Wylie, and F.E. Richart, "Soil Motion Input Motion and Site Property Variabilities on Seismic Computations by Characteristics Methods," Proceed- Site Response Analysis," Journal of Geotechnical & ings, ASCE National Structural Engineering Conference, Geoenvironmental Engineering, Vol. 136, No. 4, 2010, San Francisco, Calif., 1973. pp. 607­619. Streeter, V.L., E.B. Wylie, and F.E. Richart, "Soil Motion Rayhani, M.H.T., M.H. El Naggar, and S.H. Tabatabaei, Computation by Characteristic Method," Journal of the "Nonlinear Analysis of Local Site Effects on Seismic Geotechnical Engineering Division, Vol. 100, No. GT3, Ground Response in the Bam Earthquake," Geotechnical 1974, pp. 247­263. and Geological Engineering, Vol. 26, No. 1, 2008, pp. Sugito, M., H. Goda, and T. Masuda, "Frequency Dependent 91­100. Equi-Linearized Technique for Seismic Response Analy- Roten, D., D. Fäh, L.F. Bonilla, S. Alvarez-Rubio, T.M. sis of Multi-Layered Ground," Doboku Gakkai Rombun- Weber, and J. Laue, "Estimation of Non-linear Site Hokokushu/Proceedings of the Japan Society of Civil Response in a Deep Alpine Valley," Geophysical Journal Engineers, Vol. 493, No. 3­2, 1994, pp. 49­58. International, Vol. 178, No. 3, 2009, pp. 1597­1613. Tan, K. and M. Vucetic, "Behavior of Medium and Low Seed, H.B. and I.M. Idriss, "Influence of Soil Conditions on Plasticity Clays Under Cyclic Shear Conditions," Pro- Ground Motions during Earthquakes," Journal of Soil ceedings 4th International Conference on Soil Dynamics Mechanics and Foundation Division, Vol. 95, 1969, pp. and Earthquake Engineering, Mexico City, Mexico, 99­137. 1989, pp. 131­142. Seed, H.B., I.M. Idriss, F. Makdisi, and N. Bannerjee, "Rep- Tsai, C.-C. and Y.M.A. Hashash, "Learning of Dynamic Soil resentation of Irregular Stress Time Histories by Equiva- Behavior from Downhole Arrays," Journal of Geotechni- lent Uniform Stress Series in Liquefaction Analyses," cal & Geoenvironmental Engineering, Vol. 135, No. 6, Report No. UCB/EERC/75-29, Earthquake Engineering 2009, pp. 745­757. Research Center, University of California, Berkeley, Tsang, H.H., A.M. Chandler, and N.T.K. Lam, "Estimating Calif. Non-Linear Site Response by Single Period Approxima- Seed, H.B., R.M. Pyke, and G.R. Martin, "Effect of Multi- tion," Earthquake Engineering and Structural Dynamics, Directional Shaking on Pore-Pressure Development in Vol. 35, No. 9, 2006, pp. 1053­1076. Sands," Journal of the Geotechnical Engineering Divi- Tsuda, M., J. Steidl, R. Archuleta, and D. Assimaki, "Site- sion, Vol. 104, No. GT1, 1978, pp. 27­44. Response Estimation for the 2003 Miyagi-Oki Earth- Sheahan, T.C., C.C. Ladd, and J.T. Germaine, "Rate Depen- quake Sequence Considering Nonlinear Site Response," dent Undrained Shear Behavior of Saturated Clay," Jour- Bulletin of the Seismological Society of America, Vol. 96, nal of Geotechnical & Geoenvironmental Engineering, No. 4A, 2006, pp. 1474­1482. Vol. 122, No. 2, 1996, pp. 99­108. Vucetic, M. and R. Dobry, "Cyclic Triaxial Strain-controlled Sidarta, D. and J. Ghaboussi, "Modelling Constitutive Testing of Liquefiable Sands," Advanced Triaxial Testing of Behavior of Materials from Non-uniform Material Tests," Soil and Rock, ASTM STP 977, American Society for Test- Computers and Geotechnics, Vol. 22, No. 1, 1998, pp. ing and Materials, Philadelphia, Pa., 1988, pp. 475­485. 53­71. Vucetic, M., "Cyclic Threshold Shear Strains in Soils," Jour- Silver, M.L. and H.B. Seed, "Volume Changes in Sands dur- nal of Geotechnical Engineering, Vol. 120, 1994, pp. ing Cyclic Loading," Journal of Soil Mechanics and 2208­2228. Foundation Division, Vol. 97, No. SM9, 1971, pp. Vucetic, M. and R. Dobry, "Pore Pressure Buildup and Liq- 1174­1178. uefaction of Level Sandy Sites During Earthquakes," Steidl, J.H., "Site Response in Southern California for Prob- Research Report, Rensselaer Polytechnic Institute, Troy, abilistic Seismic Hazard Analysis," Bulletin of the Seis- N.Y., 1986, 616 pp.

38 Wang, Z.L., C.Y. Chang, and C.C. Chin, "Hysteretic Damp- Youd, T.L., "Compaction of Sands by Repeated Shear Strain- ing Correction and Its Effect on Non-Linear Site Response ing," Journal of Soil Mechanics and Foundation Divi- Analyses," Geotechnical Special Publication, Sacra- sion, Vol. 98, 1972, pp. 709­725. mento, Calif., 2008. Zhai, E., W. Roth, E. Dawson, and C. Davis, "Seismic Defor- Watabe, M., M. Tohido, O. Chiba, and R. Fukuzawa, "Peak mation Analysis of an Earth Dam--A Comparison Study Accelerations and Response Spectra of Vertical Strong Between Equivalent-Linear and Nonlinear Effective Stress Motions from Near-Field Records in USA," Eighth Japan Approaches," Paper No. 3298, 13th World Conference on Earthquake Engineering Symposium, Tokyo, Japan, Earthquake Engineering, Vancouver, B.C., Canada, 2004. 1984, pp. 301­306. Zheng, W. and R. Luna, "Nonlinear Site Response and Liq- Wilson, E., Dynamic Analysis by Numerical Integration, uefaction Analysis in the New Madrid Seismic Zone," Computers and Structures Inc., San Francisco, Calif., Geotechnical and Geological Engineering, Vol. 29, No. 2005. 4, 2011, pp. 1­13.

39 GLOSSARY Aloop: Area of hysteresis loop CPT: Cone Penetration Test [C]: velocity proportional damping matrix CSR: Cyclic Stress Ratio f1 and f2, f3, f4: Frequencies for Rayleigh viscous damping DOT: Department of transportation G : Shear modulus DSHA: Deterministic Seismic Hazard Analysis Gmax: Maximum shear modulus (usually obtained from DSS: (cyclic) Direct Simple Shear (test) shear wave velocity) EL: Equivalent-Linear h, hi: thickness of layer EPRI: Electric Power Research Institute [K ]: stiffness matrix GMPE: Ground Motion Prediction Equation k, k i: element of stiffness matrix IBC: International Building Code [M ]: Mass matrix LRFD: Load and Resistance Factor Design m: element of mass matrix MCE: Maximum Considered Earthquake qc: uncorrected tip resistance from CPT sounding MR: Modulus Re-matching only with extended Masing rule Su: undrained shear strength of soil MRD: approximate match of both modulus and damping To: Fundamental period of a soil column or structure with extended Masing rule {u}: displacement vector MRDF: Modulus reduction and damping matching with non-Masing rule Vs: Shear wave velocity NGA: Next Generation Attenuation (relationship) Vs30: (average) shear wave velocity of the top 30 meters NL: Nonlinear R : Rayleigh damping coefficient PEER: Pacific Earthquake Engineering Research Center : damping or coefficient in Newmark-type numerical inte- gration of equation of motion PI: Principal Investigator R : Rayleigh damping coefficient PSHA: Probabilistic Seismic Hazard Analysis : shear strain pwp: pore water pressure c: cyclic shear strain ReMI: Refraction Microtremor c: cyclic shear stress RVT: Random Vibration Theory tar: Target damping ratio SASW: Spectral Analysis of Surface Waves : Wilson time stepping coefficient sCPT: seismic Cone Penetration Test : mass density of soil SFSI: Soil-Foundation-Structure Interaction (the same as SSI: Soil-Structure-Interaction) 1-D: One dimensional SPT: Standard Penetration Test 2-D: Two dimensional SSI: Soil-Structure Interaction 3-D: Three dimensional UHRS: Uniform Hazard Response Spectrum CMS: Conditional Mean Spectrum USAEC: United States Corps of Engineers COSMOS: The Consortium of Organizations for Strong- Motion Observation Systems USGS: United States Geologic Survey

40 APPENDIX A Survey Questionnaire Page One--General questions 1.) Dear Colleague: The Transportation Research Board (TRB) is preparing a synthesis on Practice and Procedures for Site-Specific Evaluation of Earthquake Ground Motions, NCHRP Synthesis 20-05/Topic 42-03, State DOT's Survey. This is being done for NCHRP, under the sponsorship of the American Association of State Highway and Transportation Officials, in cooperation with the Federal Highway Administration. The synthesis study intends to identify and describe current practice and available methods for site specific analysis of earthquake ground motions. The study will include a summary of experience gained in developing and employing these methods, including challenges in their application and perceived advantages and disadvantages of the different methods. This study will help establish and improve the state of practice, providing a summary of best design practices, as well as identifying research and development needs on this important topic. This questionnaire will help us understand the current practice in site specific analysis of ground motions at selected state departments of transportation and will help us identify some of the challenges encountered when con- ducting the analyses. We appreciate you taking the time to complete this survey. Please do not hesitate to contact us should you have any questions. As a token of our appreciation we will provide you electronically with a copy of the completed study. The results of this study will be reported only in aggregate form (no individual names will be reported). This survey is being sent to state departments of transportation and their consultants. Your cooperation in completing the questionnaire will ensure the success of this effort. If you are not the appropriate person at your agency to complete this survey, please forward it to the correct person. Please compete and submit this survey by COB Friday, February 25, 2011. We estimate that it should take no more than 60 minutes to complete. If you have any questions, please contact our principal investigator Dr. Neven Matasovic (NMatasovic@ Geosyntec.com, 714-465-1244) or Prof. Youssef Hashash (hashash@illinois.edu, 217-333-6986). Any supporting materials can be sent directly to by e-mail or at the postal address shown at the end of the survey. QUESTIONNAIRE INSTRUCTIONS 1. To view and print the entire questionnaire, Click on the following link and print using "control p". 2. To save your partial answers, or to forward a partially completed questionnaire to another party, click on the "Save and Continue Later" link in the upper center of your screen on page 2 and onwards. A link to the partial survey will be e-mailed to you or a colleague. 3. To view and print your answers before submitting the survey, click forward to page 8. Print using "control p". 4. To submit the survey, click on "Submit" on the last page. Name of Respondent: ____________________________________________ Title of Respondent: _____________________________________________ Name of State Agency and office: __________________________________ Address: ______________________________________________________ E-mail: _______________________________________________________ Telephone number: ______________________________________________

41 2.) Do your following responses apply to (check all that applies)? [ ] Your own individual practice [ ] The practice of your office/number of engineers [ ] The practice of your agency/number of engineers 3.) Approximately how many of your projects involve site response analyses in a given year? ( ) 1­2 ( ) 3­6 ( ) 7­12 ( ) 13­25 ( ) 26­50 ( ) >50 4.) Guidelines and manuals for seismic site response [ ] Your agency has a manual for seismic design; please provide title and web link [ ] Your manual has provisions for seismic site response analysis/provide title and web link Page Two--Criteria and programs used 5.) When is the use of code-based site factors acceptable for characterizing site effects? [ ] Preliminary design [ ] Small structures [ ] Seismic hazard is low [ ] Always [ ] Never [ ] Other--please provide a brief narrative 6.) When is the use of computer analysis required for site response analysis? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ]Ground conditions (e.g., liquefiable soils, or organic soils, or very soft soils subjected to strong shaking, please specify) [ ] Structure type--please specify [ ] Other--please describe 7.) Of the total number of site response analyses you perform, indicate the approximate percentages that fall within each of the following categories: One-dimensional equivalent-linear: _________________________________ One-dimensional nonlinear total stress (no pore water pressure): __________ One-dimensional nonlinear effective-stress (with pore water pressure): ____ Two- or three-dimensional equivalent-linear: _________________________ Two- or three-dimensional nonlinear Total Stress Analysis: ______________ Two- or three-dimensional nonlinear Effective-Stress Analysis: __________

42 8.) What computer program(s) do you use for each of the following types of analyses (list more than one if appropriate; leave blank if you do not perform one of these types of analyses)? One-dimensional equivalent-linear: _____________________________________________ One-dimensional nonlinear--Total stress (no pore water pressure): ____________________ One-dimensional nonlinear--Effective-stress (with pore water pressure): ______________ Two- or three-dimensional equivalent-linear: _____________________________________ Two- or three-dimensional nonlinear: ___________________________________________ 9.) Please describe validation/verification requirements you have for computer code usage. Page Three--Seismic hazard motion input required for site response analysis Note for the following questions: Input ground motions are required for performing site response analysis based on specific hazard levels. The questions below will help us understand how you develop these ground motions. 10.) How do you define the seismic hazard at your site and the target rock response spectra? [ ] USGS Maps [ ] Code Provision--List code [ ] Site specific deterministic--describe program [ ] Site specific probabilistic--describe program [ ] Other, please specify: 11.) How do you develop hazard compatible ground motion time histories at rock? [ ] Simple scaling of motions from widely available libraries [ ] rigorous spectral matching (specify method if known) [ ] Synthetic ground motions [ ] Other, please specify: 12.) How many motion time histories do you generate or require for a given hazard level ( ) 1 motion ( ) 3 motions ( ) 7 motions ( ) Other, please specify: 13.) For sites where near faults effects are significant, what special requirements do you impose on the suite of input ground motions? [ ] None [ ] incorporate directivity [ ] include velocity pulse [ ] use two component motions (e.g., Fault normal/parallel) [ ] check cross-correlation of the input ground motion time histories [ ] Other, please specify:

43 14.) How do you handle uncertainty in the input ground motion? 15.) Please include other comments you may have related to the topic of input motions. Page Four--Soil profile input information required for site response analysis 16.) What special geotechnical field and laboratory investigations do you require/perform to obtain information suitable for site response analysis? [ ] None [ ] Direct measurement of shear wave velocity [ ] Cyclic triaxial, direct simple shear or resonant column tests [ ] Other, please specify: 17.) How do you obtain the shear wave velocity profile for the soil column? [ ] SPT correlations [ ] CPT correlations [ ] Seismic cone [ ] downhole [ ] crosshole [ ] suspension logger [ ] surface wave/SASW/MASW [ ] Other, please specify: 18.) How do you define the dynamic soil properties (modulus reduction and damping curves) for site response analysis? (lab testing, published correlations based soil index properties such as Darandelli, Vucetic and Dobry, Seed and Idriss...) [ ] laboratory testing [ ] Darendeli [ ] Vucetic-Dobry [ ] Seed-Idriss [ ] Other, please specify: 19.) Do you account for uncertainty in the soil profile properties? If yes, how? If not, why not? 20.) Please include other comments you may have related to the topic of soil profile input Page Five--Site response analysis 21.) When is an equivalent-linear analysis (e.g., SHAKE or similar program) used or required? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ] Structure type--please specify [ ] Other, please describe: 22.) What soil models do you usually use for equivalent-linear site response analyses (mark all that applies)? [ ] EPRI [ ] Ishibashi-Zhang

44 [ ] Iwasaki [ ] Seed-Idriss Sand [ ] Seed-Idriss Clay [ ] Vucetic-Dobry [ ] Darendeli [ ] Other: 23.) When is a nonlinear total stress (no pore water pressure generation) analysis used or required? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ] Structure type--please specify [ ] Strain amplitude--please specify [ ] Other, please describe: 24.) What soil models do you usually use for nonlinear total stress site response analyses (mark all that applies)? [ ] Hyperbolic with Masing criteria [ ] Modified Hyperbolic with Masing criteria (e.g., M-K-Z) [ ]Modified Hyperbolic with non Masing criteria (e.g., MRDF to match both modulus reduction and damping curves) [ ] Cundall-Pyke model [ ] Mohr-Coulomb [ ] Other--whatever model is included in my software--please specify: [ ] It is important for the model to match both modulus reduction and damping curves [ ] It is only important that the model matches modulus reduction regardless of the damping curve. 25.) When is a nonlinear effective-stress (with pore water pressure generation) analysis used or required? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ] Structure type--please specify [ ] When porewater pressure ratio exceeds a given value--please specify [ ] Other, please describe: 26.) What soil models and porewater pressure generation models do you use in nonlinear effective-stress site response analyses (mark all that applies)? [ ] Dobry [ ] Elgamal [ ] GMP (Green) [ ] Martin-Finn-Seed [ ] Matasovic (Modified Dobry et al. porewater pressure model) [ ] UBC Sand [ ] Other

45 Page Six--Evaluation and use of results 27.) What do you consider to be the top three uncertainties in the input to a typical seismic site response analysis? [ ] Low-strain stiffness (represented by Gmax or Vs) [ ] Higher strain stiffness (represented by modulus reduction or backbone curve) [ ] Small strain damping behavior represented by viscous damping [ ] Large strain damping behavior (represented by damping curve or unloading-reloading model) [ ] Soil layer thickness [ ] Depth to bedrock [ ] Character of bedrock (Vs, modulus reduction and damping behavior) [ ] Input motions [ ] Other: 28.) How do you typically account for such uncertainties in design? [ ] Select reasonably conservative values of input parameters [ ] Use "best estimate" input parameters, then apply conservatism to results [ ] Perform sensitivity analyses [ ] Perform probabilistic analyses (e.g. FOSM, Monte Carlo) [ ] We don't address uncertainties explicitly [ ] Other, please specify: 29.) How do you evaluate the validity of the overall site response model at your site? [ ] Compare with empirical correlations [ ] Perform sanity checks [ ] Other, please specify: 30.) What output do you use from site response analysis? [ ] Surface response spectra [ ] Surface velocities [ ] Surface displacements [ ] Surface time histories [ ] Profiles of PGA [ ] Profiles of strains [ ] Profiles of displacements [ ] Profiles of shear stress [ ] Other, please specify:

46 31.) Do you use output of profiles of strains and lateral deformations in a structural analysis? (e.g., pile lateral loading...), please explain, do you perform any baseline correction of the output motions? 32.) Do you use profile of peak ground acceleration for liquefaction analysis? Please explain. When you evaluate cyclic stress ratio (CSR) for liquefaction analyses, how often do you do so by means of site response analyses (as opposed to using the simplified method)? What criteria do you use for deciding when to do so? 33.) Do you use profile of peak ground acceleration for slope stability analysis? Please explain. 34.) For analyses where pore water pressure generation is evaluated, how do you use the analysis output? 35.) Please include other comments you may have related to the topic on evaluation and use. Page 7--Helpful contacts 36.) As part of this synthesis study we will also survey private consulting firms and engineers who conduct site specific response analysis. Can you please provide us with contact information of key firms and engineers that provide site response analysis services to your DOT? Firm Name Contact Person Contact information Contact 1 ___ ___ ___ Contact 2 ___ ___ ___ Contact 3 ___ ___ ___ Contact 4 ___ ___ ___ Contact 5 ___ ___ ___ Contact 6 ___ ___ ___ Contact 7 ___ ___ ___ Contact 8 ___ ___ ___ Contact 9 ___ ___ ___ Contact 10 ___ ___ ___ 37.) Please feel free to include any thoughts or comments you would like to share with us. Thank You! Thank you for taking our survey. Your response is very important to us. Postal address: Dr. Neven Matasovic Geosyntec 2100 Main St, Suite 150 Huntington Beach, CA 92648

47 APPENDIX B Compiled Survey Responses 2.) Do your following responses apply to (check all that applies)? [ ] Your own individual practice [ ] The practice of your office/number of engineers [ ] The practice of your agency/number of engineers TABLE B1 APPLICABILITY OF RESPONSE TO ENGINEERING PRACTICE Respondents Count # of Engineers Range of # of Engineers Ave/Total Your own individual practice 10 The practice of your office 17 93/1298 3­500 The practice of your agency 14 49/246 1­100 3.) Approximately how many of your projects involve site response analyses in a given year? ( ) 1­2 ( ) 3­6 ( ) 7­12 ( ) 13­25 ( ) 26­50 ( ) >50 TABLE B2 NUMBER OF PROJECTS INVOLVING SITE RESPONSE ANALYSES IN A GIVEN YEAR No. of Projects Count 1­2 12 3­6 3 7­12 8 13­25 3 26­50 1 4.) Guidelines and manuals for seismic site response [ ] Your agency has a manual for seismic design; please provide title and web link [ ] Your manual has provisions for site response analysis/provide title and web link TABLE B3 RESPONDENTS WHO USE GUIDELINES AND MANUALS FOR SEISMIC SITE RESPONSE Count Your agency has a manual for seismic design 12 Your manual has provisions for seismic site 10 response analysis

48 TABLE B4 GUIDELINES AND MANUALS FOR SEISMIC SITE RESPONSE 1 Caltrans Seismic Design Criteria http://www.dot.ca.gov/hq/esc/earthquake_engineering/SDC_site/ 2 http://www.wsdot.wa.gov/Publications/Manuals/M46-03.htm 3 Internal draft guidelines that are not for public release. 4 http://www.dot.il.gov/bridges/brmanuals.html 5 2009 LRFD Seismic Design Provisions; NCHRP Report 611 6 2009 LRFD Seismic Design Provisions; NCHRP Report 611 7 ASCE 7, ASCE 4, ASCE43-05, NRC RG 1.208; U.S. Army Corps of Engineers EM110-2-6050 8 AASHTO LRFD Specifications 9 http://www.dot.ca.gov/hq/esc/earthquake_engineering/SDC_site/ 10 Geomotions 11 ODOT Geotechnical Design Manual ftp://ftp.odot.state.or.us/techserv/Geo-Environmental/Geotech/ GeoManual/FinalGDM12-10-09/Volume1GeotechDesignManualFinal_Dec2009.pdf 12 http://www.wsdot.wa.gov/Publications/Manuals/M46-03.htm 13 http://www.scdot.org/doing/bridge/bridgeseismic.shtml, http://www.scdot.org/doing/bridge/ geodesignmanual.shtml 14 GA DOT website 15 http://www.dot.ri.gov/documents/engineering/br/RILRFDBridgeManual.pdf Page Two--Criteria and programs used 5.) When is the use of code-based site factors acceptable for characterizing site effects? [ ] Preliminary design [ ] Small structures [ ] Seismic hazard is low [ ] Always [ ] Never [ ] Other, please provide a brief narrative: TABLE B5 CIRCUMSTANCES WHEN THE USE OF CODE-BASED SITE FACTORS IS ACCEPTABLE FOR CHARACTERIZING SITE EFFECTS Count Preliminary design 16 Small structures 12 Seismic hazard is low 14 Always 11 Never 0 Other ­ See next table 17

49 TABLE B6 ADDITIONAL CIRCUMSTANCE WHEN THE USE OF CODE-BASED SITE FACTORS IS ACCEPTABLE FOR CHARACTERIZING SITE EFFECTS 1 Site Classes A through E 2 All cases except for Site Class "F" locations, which are typically susceptible to liquefaction. 3 Exceptions: Non-ordinary structures as defined in SDC, Soil type F 4 For buildings it is acceptable for sites other than Site Class F, for bridges it is acceptable for site class other than F and when the bridge is not critical, for other structures it depends on the code standards and the criti- cality of the project. 5 More conservative site is assumed. 6 As per AASHTO recommendations, site class F and also as per ODOT GDM Section 6.5.1.4 7 Most structures except when the conditions stated in Q6 below apply. 8 We will generally use the code-based site factors either at the start of a project or to compare/check results from site response analyses 9 Although it is important to understand the general site response behavior in your environment (i.e., if you work in Boston--you should have done at least one site response computation with a typical profile--to understand the local issues. 10 Always, except very large expensive/critical structures 11 For soils other than soft/liquefiable soils 12 We only use for small to mid-size CBC projects. Almost everything else uses some form of NGA. 13 structures of low importance 14 For most of the bridges in New York State being in low seismic zone. 15 When the site is not site class F 16 Code-based site factors are used where seismic hazard is simple (no long duration, directivity, basis) and site conditions are not anticipated to result in a code exceedance, and where the cost impact of conservative design is not significant 17 A. Typically SCDOT uses the site factors for the vast majority of our bridges; however, depending on the bridge a Site-Specific Response Analysis may be required. The SCDOT 2008 Seismic Design Specifica- tions for Highway Bridges and the 2010 Geotechnical Design Manual delineate when a Site-Specific Response Analysis is required. In addition, SCDOT may require a Site-Specific Response Analysis for bridges that are considered major. Currently SCDOT has a research project reviewing and developing new site factors for South Carolina. 6.) When is the use of computer analysis required for site response analysis? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ]Ground conditions (e.g., liquefiable soils, or organic soils, or very soft soils subjected to strong shaking, please specify) [ ] Structure type--please specify [ ] Other, please describe: TABLE B7 CIRCUMSTANCES WHEN SITE RESPONSE ANALYSIS IS REQUIRED Count Site class dependent 27 Seismic hazard 14 Ground conditions (e.g., liquefiable soils, or organic 28 soils, or very soft soils subjected to strong shaking) Structure Type 19 Always 12

50 TABLE B8 SITE CLASS REQUIRED FOR SITE RESPONSE ANALYSIS (NUMBER IN PARENTHESIS IS RESPONDENTS COUNT) F(20), F (for all bridges, T > 0.5 sec), E(10) E (deep sites, high motion, critical bridges), D(3), C(2). When required by code, when unique soil conditions exist, when there appears to be advantage to the client, or when the client requires. Often we will look to the site analysis for higher PGA values and for deeper soil profiles. B. A Site-Specific Response Analysis is required for Site Class F as defined in the 2010 Geotechnical Design Manual. Certain bridge types (i.e., spans greater than 300 feet, etc.) or as determined by SCDOT personnel. See p. 12-22, GDM (2010) TABLE B9 SEISMIC HAZARD LEVEL REQUIRED FOR SITE RESPONSE ANALYSIS 1 We do site specific analysis to determine input parameters for simplified liquefaction analysis. 2 hazard level not covered by codes 3 PBA > 0.2 g 4 PGA > 0.6 g and the site is near major fault(s) capable of generating large earthquakes 5 PGA values that could result in soil nonlinearity or liquefaction 6 High 7 high ground motions 8 PGA > 0.15g 9 For certain conditions specified by CBC 2010 10 When the design is required for higher hazard level than the 2500 year return earthquake 11 high hazard TABLE B10 GROUND CONDITIONS WHEN SITE RESPONSE ANALYSIS IS REQUIRED 1 Liquefaction 2 Liquefiable soils, or organic soils 3 Site class F sites 4 F sites, deep E sites 5 Liquefiable site 6 Section 6.5.1.4 in ODOT GDM 7 Sites with soft soils that display significant degradation of strength and stiffness under strong ground shaking. Sites with surficial soil lay- ers that have drastically different strength and stiffness (e.g., soft clay over rock). 8 Deep soils, liquefiable soils, very soft soils 9 Liquefiable soils, deep soft clay profiles, or when the soil profile makes the simplified site factors suspect 10 Any unusual soil conditions--very deep, liquefiable, organic soils--or other soils with unusual behavior, sharp impedance contrasts... 11 liquefiable soils 12 liquefiable soils 13 soft soils such as Bay Mud and liquefiable soils in strong shaking areas 14 large impedance contrast 14 brittle quarry slopes subject to strong shaking 16 Most codes require site response for liquefiable sites 17 liquefiable soils or significant amounts of soft soils 18 liquefiable soils, expected significant site effect, soft soils 19 all conditions that will classify the site as site class F 20 Liquefiable soils 21 liquefiable soils, soft soils 22 same as site class F 23 liquefiable or soft soils, high impedance contrasts

51 TABLE B11 STRUCTURE TYPE WHERE SITE RESPONSE ANALYSIS IS REQUIRED 1 lifeline, "mega-bridge" structures such as the Knik Arm Crossing 2 Non-ordinary structures as defined in SDC (life line bridges, large toll bridges, etc.) 3 Occ IV, critical facilities 4 high-rise tower >>50 story 5 Base isolation 6 High rises/highly irregular structures that requires dynamic time history analysis to be completed for design, and essential buildings/ structures/bridges. 7 Essential Bridges 8 Critical or essential bridges--or where there is a significant cost associated with use of simplified site factors 9 high risk 10 Critical structures 11 Critical structure or base-isolated structure 12 high importance 13 Nuclear Structure in Safety Category I and II 14 critical structures 15 irregular, special structures 16 For larger projects; e.g., bridges and dams will be required regardless of site class 17 Significant or complicated structure requiring more in-depth analysis for economical design TABLE B12 OTHER CONDITIONS WHERE SITE RESPONSE ANALYSIS IS REQUIRED 1 offshore structures 2 For projects where earthquake time histories at depths are needed for design analysis of the structures. 3 performance-based structural analysis 4 http://www.dot.il.gov/bridges/AGMU%20091.pdf 5 We rely on site class definition based on Method B (N values) and use USGS maps to calculate the 5% damped design response spectrum 6 client request 7 To be considered in the future 8 Liquefiable Soils 9 Sometimes done when SE is doing sophisticated time history analyses, so more sophisticated ground motion development is warranted. 10 Research 11 We do a computer analysis for bridges in Seismic Performance Category B zones. Georgia does not have and SPC C or D bridges 7.) Of the total number of site response analyses you perform, indicate the approximate percentages that fall within each of the following categories: One-dimensional equivalent-linear: _____________________________________________ One-dimensional nonlinear--Total stress (no pore water pressure): ____________________ One-dimensional nonlinear--Effective-stress (with pore water pressure): ______________ Two- or three-dimensional equivalent-linear: _____________________________________ Two- or three-dimensional non-linear--Total Stress Analysis: ________________________ Two- or three-dimensional non-linear--Effective-Stress Analysis: ____________________

52 TABLE B13 APPROXIMATE PERCENTAGES OF SITE RESPONSE ANALYSES THAT FALL WITHIN EACH OF THE FOLLOWING CATEGORIES, NUMBER IN PARENTHESES IS NUMBER OF RESPONDENTS One-dimensional equivalent-linear 0% (2), 30% (2), 35% (1) 40% (1), 50% (2), 60% (1), 65% (1), 70% (2), 75% (2), 80% [28, respondents] (2), 90% (1), 100% (13) One-dimensional nonlinear--Total stress (no pore 0% (3), 3% (1), 5% (1), 10% (3), 100% (1), 15% (1), 20% (3), 25% (1), 30% (1), 50% water pressure) [17] (2), 70% (1), 85% (1) One-dimensional nonlinear--Effective-stress (with 0% (2), 3% (1) 10% (3), 15% (2), 20% (2), 25% (2), 30% (2), 40% (2), 100% (1), always pore water pressure) [18] in parallel with equivalent linear Two- or three-dimensional equivalent-linear [7] 0% (4), 10% (1), 15% (2) Two- or three-dimensional non-linear--Total Stress 0% (4), 5% (1), 10% (1), 15% (1), 100% (1). usually we run FLAC analysis and use one Analysis [8] dimensional analysis to get the input motion at the base of the model Two- or three-dimensional non-linear--Effective- 0% (1), 5% (4), 15% (1), 20% (1), 25% (1), 40% (1) Stress Analysis [10] 8.) What computer program(s) do you use for each of the following types of analyses (list more than one if appropriate; leave blank if you do not perform one of these types of analyses)? One-dimensional equivalent-linear: _____________________________________________ One-dimensional nonlinear--Total stress (no pore water pressure): ____________________ One-dimensional nonlinear--Effective-stress (with pore water pressure): ______________ Two- or three-dimensional equivalent-linear: _____________________________________ Two- or three-dimensional nonlinear: ___________________________________________ TABLE B14 SOFTWARE PROGRAMS USED FOR SITE RESPONSE ANALYSIS, NUMBER IN PARENTHESES IS NUMBER OF RESPONDENTS One-dimensional equivalent-linear SHAKE2000 (12), SHAKE (10), DEEPSOIL (4), SHAKE 91 (4), PROSHAKE (3), Shake-Edit (1), SCDOT SHAKE, in-house, No limits in the past - any program, Assi- maki and Kausel. One-dimensional nonlinear--Total stress (no pore D-MOD2000 (12), DEEPSOIL (7), FLAC (3), OpenSees (1), SIREN (1), Finite differ- water pressure) ence code developed @ GATech (1) One-dimensional nonlinear--Effective-stress (with D-MOD2000 (13), DEEPSOIL (3), FLAC (4), OpenSees (1), DYNAFLOW (1), various pore water pressure) Two- or three-dimensional equivalent-linear QUAD4M (6), FLAC (3), SIGMA/W (1), Quake/W (2), SUMDES (1), SASSI (1), ABAQUS (1), Seisab (1) Two- or three-dimensional non-linear FLAC (8), ABAQUS (2), PLAXIS (2), Dynaflow (1),

53 9.) Please describe validation/verification requirements you have for computer code usage. TABLE B15 VALIDATION/VERIFICATION REQUIREMENTS FOR COMPUTER CODE USAGE Count Response 1 Compare with code spectra 1 Comparison between different codes; comparison to known solutions 1 Comparison between different computer codes. 1 Downhole array data, centrifuge experimental studies 1 None used 1 Peer review 1 SHAKE--verified according to nuclear standards Deepsoil--used verification from literature 1 Site Response Analysis has been done by the Consultants. 1 We have been using FLAC and SHAKE for a long time and have developed a feel for it. 1 Described in Kwok et al. paper in JGGE 1 in-house procedure 1 None 1 Verify total stress between DMOD and SHAKE under small PBA where nonlinearity is minimal. 1 Peer review of non-linear Comparison of equivalent-linear, non-linear, and predicted ground motions of code and attenuation models. 1 Compare with previous studies--Check strain levels to see if 1-D equiv. lin. is applicable--Check stress levels to see if 1-D equiv. lin. is applicable--Check 2-D equiv. lin. results with 1-D equiv. lin.--Check 1-D total stress and effective-stress results with 1-D equiv. lin.--Do parametric runs to check model sensitivity (input motions, G-gamma curves, depth to bedrock, Vs). 1 All of the site response work I do is for research purposes. We use vertical array data to validate the code and make recommendations on site response methodology. 1 Typically, validation requirements involve an alternate calculation showing similar/identical results. However, critical and nuclear projects have required NQA-1 software V&V standards, which are much more stringent. 1 Prior to completing a 1-D nonlinear total stress analysis, a equivalent-linear must be completed. Prior to completing a 1-D nonlinear effective-stress analysis, the soil liquefaction analysis using the simplified method and the 1-D nonlinear total stress analysis must be completed. Prior to completing a 2-D analysis, a compatible 1-D analysis must be completed along with simplified analysis that will help calibrate the soil models used. I would not consider a 3-D analysis for design unless the earthquake loading can be modeled in 3-D and that research has shown the soil models available are adequate for 3-D analysis. 3-D modeling may be used to augment the 2-D modeling for design. 1 Varies highly by project. Some projects have no requirements. Some DOTs require only software from "pre-approved lists" be used. NRC and DOE require highest levels of V&V. 1 We are now using CSI Bridge (SAP) and we are in the process of working out our differences with our geotechnical engineers regard- ing liquefaction. 1 Check output (shear stress, strain levels, etc.) to see how they compare with reasonable ranges for the modeled soils, compare spectra to results from other previous analysis of sites with similar conditions. 1 Compare several programs of similar capabilities and against case studies with documented field data of performance. Some centri- fuge tests as well. 1 During our extensive seismic retrofit program (1990 to 2000) we validated SHAKE with recordings from downhole arrays. 1 First let me explain that if we are using an effective-stress analyses, we are always conducting total stress analyses with the same pro- gram. So I made the numbers for these methods the same. We rarely would conduct a nonlinear total stress analysis by itself, because we don't find many sites that would warrant only this type of analysis. This is a little different for PLAXIS and FLAC where we have conducted seismic slope stability analyses for clay slopes. Now regarding calibration, we try to validate use of the code when we receive it by comparing to problems in the user's manual. If a person is running the code for the first time, we make sure he/she can validate the code against the user's manual. For equivalent-linear SHAKE analyses, we validate by checking input/output during our QA/QC process. We will also run suites of EQ records to define a range of motions, and we will vary the soil model to evaluate typical response. We will also compare against code-based site class factors (though usually these differ). We follow much the same process for the nonlinear codes. We will also compare total stress from SHAKE versus DMOD. We will also calibrate the soil model against lab and field data. For FLAC and PLAXIS we would calibrate a column versus SHAKE for the free field. 1 Validation checked by running results in Bridge Pier Program and looking at changes in footings and column sizes. 1 C. According to Chapter 26 of the GDM (2010) commercially available software packages are typically produced by either a univer- sity or software development firm and sold for profit. Software developed in this manner normally goes through extensive QA/QC prior to being sold. Therefore, the only documentation SCDOT requires for these software packages is the contact information for the developer. Software obtained from the FHWA website requires no additional information. 1 For NQA1 projects, we do have a V&V process. For all other projects, we rely on the V&V done by the vendor of the commercial software.

54 Page Three--Seismic hazard motion input required for site response analysis Note for the following questions: Input ground motions are required for performing site response analysis based on specific hazard levels. The questions below will help us understand how you develop these ground motions. 10.) How do you define the seismic hazard at your site and the target rock response spectra? [ ] USGS maps [ ] Code Provision--List code [ ] Site specific deterministic--describe program [ ] Site specific probabilistic--describe program [ ] Other, please specify: TABLE B16 METHODS TO DEFINE THE SEISMIC HAZARD AND THE TARGET ROCK RESPONSE SPECTRA-- SEE DETAILED RESPONSES UNDER EACH ITEM ON THE NEXT TWO PAGES Value Count USGS Maps 22 Code Provision--List code 19 Site specific deterministic--describe program 13 Site specific probabilistic--describe program 21 Other, please specify: 9 Code Provision Site specific deterministic AASHTO LRFD (USGS 1000 year hazard maps) New Generation Attenuation Equations (NGA) AASHTO LRFD Bridge Design EZ-FRISK Ibc gis-hazard ASCE 7 SISMIC, Open SHA ASCE 7-05 and AASHTO GMPE available in SHAKE-2000 for Subduction Zone Earthquake and the NGA GMPE spreadsheets AASHTO available from PEER web site AASHTO CD for DOT projects MathCAD with NGA models for crustal motions. IBC Our California offices use Tom Blake's programs AASHTO LRFD EZ-FRISK/PEER NGA spreadsheet International/California Building Code Spreadsheets (NGA-based) AASHTO, USEPA guidance NGA CBC, IBC EZ-FRISK or deterministic attenuation model spreadsheet NEHRP EZ-Frisk, Spreadsheet Template NYCDOT Seismic Guidelines in-house IBC, NEHRP, AASHTO NBCC (national building code of Canada) USGS deagg AASHTO 17th Edition AASHTO Site specific probabilistic Other, please specify: PSHA Deaggregate PSHA maps for fault data to use with liquefaction analysis Deaggregated data from USGS website Most of the time we are using the USGS Maps An internal tool (ARS online) based on USGS 1,000 yr RP Seismologist Table continued on p.55

55 Table continued from p.54 Site specific probabilistic Other, please specify: EZ-FRISK USGS deaggregation gis-hazard, EZ-FRISK USGS Interactive Deaggregation website HAZ38 & USGS software USGS NSHMP Java program SISMIC, Open SHA Source-specific attentuation for predominant sources, CMS utilized for target Site specific PSHA completed by others that uses the computer program HAZ-38 or later D. SCDOT uses software exclusively developed for SCDOT called SCENARIO_PC to determine We subcontract this to a specialist ground motions for both geologically realistic and Rarely do these analyses, but we have our own hard rock. The software was developed by a part- PSHA model and we have leased the PSHA code nership of USC (University of South Carolina) and from Risk Engineering. We have also used Tom Virginia Tech. The program accounts for the Blakes program in the past for locations in extremely thick (in excess of 2,900 feet) soil thick- California. ness adjacent to Coastal South Carolina. EZ-FRISK openSHA EZ-FRISK EZ-FRISK EZ-FRISK or HAZ42 compared with USGS maps Developed by Geophysical Institute of Israel EZ-Frisk in-house in house 11.) How do you develop hazard compatible ground motion time histories at rock? [ ] Simple scaling of motions from widely available libraries [ ] rigorous spectral matching (specify method if known) [ ] Synthetic ground motions [ ] Other, please specify: TABLE B17 METHODS TO DEVELOP HAZARD COMPATIBLE GROUND MOTION TIME HISTORIES AT ROCK (FIRST ONE IS SIMPLE SCALING)--SEE DETAILED COMMENTS ON THE NEXT PAGE Value Count Simple scaling of motions from widely available libraries 18 Rigorous spectral matching (specify method if known) 19 Synthetic ground motions 12 Other, please specify 8 Rigorous spectral matching methods Other, please specify: RASCAL Synthetic and Scaled Real RSPMATCH we don't do this Inhouse No RspMatch (rarely used) Risk Engineering Time Histories for NYCDOT RSPMatch 2005 It usually comes from owner's engineers--the majority are based on spectral matching--some agencies prefer RSPMatch linear scaling for a specific period of interest We typically subcontract this SigmaSpec used for predominant periods of interest We use RSMatch in SHAKE2000. We also have a version Don't use. of the Abrahamson code that we have used on projects. Table continued on p.56

56 Table continued from p.55 Rigorous spectral matching methods RSPMatch Rspmatch done by others Typically we use RSPMatch. Have also used Tinker. RSPMatch software RspMatch Jack Baker Abrahamson RSPMATCH Shahbazian, A. and S. Pezeshk. (2010). "Improved Velocity and Displacement Time Histories in Fre- quency-Domain Spectral-Matching Procedures." Bulletin of the Seismological Society of America, 100(6), pp. 3213­3223, Dec. 2010, doi: 10.1785/0120090163 RSPmatch 12.) How many motion time histories do you generate or require for a given hazard level ( ) 1 motion ( ) 3 motions ( ) 7 motions ( ) Other, please specify: TABLE B18 NUMBER OF MOTIONS TIME HISTORIES GENERATED OR REQUIRED FOR A GIVEN HAZARD LEVEL Value Count 3 motions 4 7 motions 10 Other, please specify 20 Other, please specify: 3 real + 1 synthetic This is so seldom done, that we have no standard or requirements. We generally look at perhaps 3. 1 for Resp. Spect. Analyses and 3 for Time Histories Use 3 if matched to design bedrock spectra, use 7 if simple scaling is used 7 pairs or 14 time histories We will use 3 to 7, depending on the project. Most of the time we would like to have at least 3 motions represent- ing the 3 seismic sources in the PNW (crustal, subduction interface and subduction intraface). For geotechnical modeling, we will usually use a minimum of 7. We will use three if we are doing spectra matching for structural purposes. we don't use 0 NA 5 or 7 varies by project, usually selected by SE multimodal not considered Table continued on p.57

57 Table continued from p.56 Other, please specify: 3 to 7. But we typically try to use at least 7. If using spectral matching, typically only 3 motions. If using scaling, 7 or more. Monte Carlo convergence Nuclear 1, hydro facility 3, other facility 7 We generate thousands to develop a probabilistic approach For the recent large projects the trend has been 6 motions per level of earthquake (say 6 for 475 yr EQ)- some agen- cies (for school retrofit) require 10 motions Typically 3 if matched, 7 or more if not, depending on the problem Not used. 13.) For sites where near faults effects are significant, what special requirements do you impose on the suite of input ground motions? [ ] None [ ] incorporate directivity [ ] include velocity pulse [ ] use two component motions (e.g., Fault normal/parallel) [ ] check cross-correlation of the input ground motion time histories [ ] Other, please specify: TABLE B19 SPECIAL REQUIREMENTS IMPOSED ON THE SUITE OF INPUT GROUND MOTIONS FOR SITES WHERE NEAR FAULTS EFFECTS ARE SIGNIFICANT Value Count None 7 Incorporate directivity 15 Include velocity pulse 14 Use two component motions (e.g., Fault normal/parallel) 16 Check cross-correlation of the input ground motion time 6 histories? Other, please specify: 10 Other, please specify: never encountered Work in progress; near faults reviewed for significance, depending on importance of bridge detailed analysis may be performed considering directivity and pulse effects. We use the Caltrans approach for adjusting the spectra. not applicable Presently considering different approaches Select the existing motions near the faults that have velocity pulse No experience or any structures near faults This is beyond my expertise. No faults are visible in South Carolina due to the thickness of the Coastal Plain deposits.

58 14.) How do you handle uncertainty in the input ground motion? TABLE B20 HANDLING OF UNCERTAINTY IN THE INPUT GROUND MOTION By including phase spectra from real intraplate earthquakes in the analysis Depending on the EQ, we sometimes use plus one sigma motions. I am mostly using input/output pairs--so the input motion is not uncertain. Input of a number of records from different earthquakes and different sites Monte Carlo simulations on amplitude, duration & frequency content NA Not handled Nothing specific other than number of time histories Rock motion input motions are selected considering different fault rupture propagation scenarios Should consider more time histories Use more time histories if within 40 km of causative fault When synthetics are generated a Monte Carlo simulation can be developed. by selecting a representative suite follow AASHTO, we are not seismic experts mainly be running a minimum number of motions (say 6 to 10) probabilistic evaluation parametric sensitivity studies Select no more than two motions from any event use 7 ground motions. We will evaluate a range of ground motions representing different possible earthquakes. When selecting the input motions, we try to select records that are characteristic of the likely sources, relative to distance, magnitude, and style of faulting. Our rock is usually very deep, and so we often look at the effects of varying input level. Once we have results, we will make a judgment based on the spectral amplification factor to determine whether we use the mean or envelope the SAF. Typically handled by incorporating sigma from the attenuation relationships into the PSHA. For DSHA, I sometimes use the 84th-percentile ground motions for critical structures. Compare the computed spectrum using random vibration theory approach where time histories are not required and target rock spectrum is the only input. Perform the spectra matching to make sure the spectra ordinates not less than 90% of the target. Check strong motion duration. Check power spectra density. Conservatism in analysis; e.g., using envelope spectra, when peak motions occur at different times, and at different directions/orientations. If the objective of the site response analysis is to develop a mean response spectrum for design, then I will use 7 pairs of time histories that are scaled within ±50% of the target spectrum and computed site specific soil amplification factors. If the objective is to evaluate the site response for a given force level specified by the target spectrum, then a suite of 7 spectrally matched time histories that has the seismic characteristics (e.g., near-fault, duration) of the various sources will be used in the analysis. I'm not sure if I understand what this question is getting at. Do you mean uncertainty that the spectrally matched ground motion is representative of the design ground motion? If so, this is mitigated through use of multiple input motions. The uncertainty is handled using 7 motions that either match the target spectrum on average or are spectrally matched. We try to pick the motions from different earthquakes, similar earthquake magnitudes, significant durations, similar tectonic regimes and soil/rock conditions. How much historical data do we have? Even are developed models are a composite of other EQ. So we have a great deal of uncertainty. Use PSHA maps Use multiple time-histories for each source for input Perform sensitivity analysis of soil properties Use mean + 1SD for design response spectrum. Through the use of 7 appropriate (mechanism, distance, magnitude, near-fault etc.) time histories; results are averaged, however, decreasing variability. A parametric study is required, which involves changing soil properties and moving the B-C boundary vertically in the soil column. Use of mul- tiple motions. Typically handled through enveloping of results from analysis. Also assisted through use of ground motions with some consistency in the peri- ods of interest. Spectral matching used in cases of time-series input to structural analysis. In generating artificial earthquake, there are uncertainties in all seismological parameters such as stress drop, kappa, geometric attenuation, etc. We consider uncertainties in all these parameters and develop a set of logic trees to handle them.

59 15.) Please include other comments you may have related to the topic of input motions. TABLE B21 GENERAL COMMENTS ON THE TOPIC OF INPUT MOTIONS Georgia is a low seismic risk state. Most of this is not required. I generally shy away from synthetic motions and spectral averaging (too black boxy). I support use of CMS No consensus on proper use so we don't play expert at this time. We typically subcontract development of site specific input motions to a specialist. I have done some work on looking at the variability of input motions for Boston Massachusetts--where we choose input motions that fall within a bounded spectral range. Ground motion scaling and selection is a topic of research. We are working on several aspect of this problem. Many site characteristic factors, such as magnitude, type of earthquake, epicenter distance, impact the input motion selection. It is lack of spe- cific guideline for how to select the input motions in most of code or provision. It is important to understand the objectives of the site response analysis and the predominant periods of the structures to be constructed at the site. Also, the analysis should be completed using a suite of time histories that are representative of the seismic hazard at the site. In Utah where bedrock can be very deep, there appears to be a disproportionate number of professionals that de-convolve ground motions to bedrock. I was always taught that such practices can be risky, especially when little is known about the true depth of bedrock and the overlying soils are soft and subject to large strains. I have always developed target response spectra and ground motions for Site Class C soils and applied them in my model as input at depths where I know Site Class C soils exist. This is a topic that has come under heavy debate here in Utah, and some guidance would be welcomed. Need consensus among researches how to develop motions that meet the target spectrum either UHS or CMS. Using the CSI Bridge and the USGS maps for our higher level analysis using the guide spec appears to be our best option. Note that new PEER ground motion selection website is a very promising tool. http://peer.berkeley.edu/peer_ground_motion_database/ More guidance is needed in this area--particularly for spectral matching versus scaling. We usually scale if we are interested in pore pressure response, but we will spectrally match if there is no liquefaction and the results will be used by the bridge engineer. We typically like to spectrally match the time histories instead of scaling. However, selection of appropriate time histories is an art and should be done carefully. Page Four--Soil profile input information required for site response analysis 16.) What special geotechnical field and laboratory investigations do you require/perform to obtain information suitable for site response analysis? [ ] None [ ] Direct measurement of shear wave velocity [ ] Cyclic triaxial, direct simple shear or resonant column tests [ ] Other, please specify: TABLE B22 SPECIAL GEOTECHNICAL FIELD AND LABORATORY INVESTIGATIONS DO YOU REQUIRE/PERFORM TO OBTAIN INFORMATION SUITABLE FOR SITE RESPONSE ANALYSIS Value Count None 4 Direct measurement of shear wave velocity 30 Cyclic triaxial, direct simple shear or resonant column 12 tests Other, please specify: 6 Table continued on p.60

60 Table continued from p.59 Other--please specify: As a minimum, we would like Vs measurements in the field, but this does not always happen. On some projects we are able to justify cyclic testing--particularly if stability issues are a problem. Most of the testing is on silts for pore pressure response and post-cyclic behavior (residual strength and volumetric strain). dependent on location/structure sampling to detail stratigraphy Most projects use correlations for G/Gmax and damping curves. However, we do use in-house RCTS testing when needed. Cyclic hollow-cylinder tests Usually shear wave velocity along with G/Gmax and damping curves out of literature. 17.) How do you obtain the shear wave velocity profile for the soil column? [ ] SPT correlations [ ] CPT correleations [ ] Seismic cone [ ] downhole [ ] crosshole [ ] suspension logger [ ] surface wave/SASW/MASW [ ] Other, please specify: TABLE B23 METHODS TO OBTAIN THE SHEAR WAVE VELOCITY PROFILE FOR THE SOIL COLUMN Count SPT correlations 21 CPT correlations 16 Seismic cone 23 Downhole 19 Crosshole 12 Suspension logger 19 Surface wave/SASW/MASW 19 Other, please specify: 9 Other--please specify: How do you obtain the shear wave velocity profile for the soil column> Re-Mi Occasionally we will have resonant column/torsional shear tests conducted. We use SPT blow counts, not shear wave velocity. Refraction Microtremor (ReMi) downhole array seismogram inversion ReMi On occasions when cost does not allow measurements, we use SPT to correlate to Vs based on this article: "Empirical Relationships To Estimate Shear-Wave Velocity Profiles From SPT Information in the New Madrid Seismic Zone," M.S. Thesis, 2009, Andy Kizzee Mainly SCPT sometimes other geophysical tests (downhole crosshole.).

61 18.) How do you define the dynamic soil properties (modulus reduction and damping curves) for site response analysis? (lab testing, published correlations based soil index properties such as Darandelli, Vucetic and Dobry, Seed and Idriss...) [ ] laboratory testing [ ] Darendeli [ ] Vucetic-Dobry [ ] Seed-Idriss [ ] Other, please specify TABLE B24 DEFINITION OF DYNAMIC SOIL PROPERTIES (MODULUS REDUCTION AND DAMPING CURVES) FOR SITE RESPONSE ANALYSIS Count Laboratory testing 11 Darendeli 15 Vucetic-Dobry 20 Seed-Idriss 18 Other, please specify 20 Other, please specify: Honestly not sure EPRI For Peat we may use no G-gamma reduction or Rollins et al. In-house for east coast soils EPRI (1993) EPRI We will also use lab tests, as above USGS Seismic Design Parameters (Version 2.10) Menq from UT in sands Hardin and Drnevich Not considered at this time EPRI (1993), Matasovic and Kavazanjian (1998), Rollins (1998), Schnabel (1973) Roblee and Chiou Geoindex curves Constitutive modeling "experiments," analytical expressions using constitutive models (e.g., Assimaki et al. 2000). EPRI, Stoke published data mainly above EPRI G.SCDOT uses the correlations developed by Andrus. These correlations were developed specifically for soils in South Carolina. correlated from SPT information

62 19.) Do you account for uncertainty in the soil profile properties? If yes, how? If not, why not? TABLE B25 UNCERTAINTY IN THE SOIL PROFILE PROPERTIES Response 1 Multiple profiles--upper bound and lower-bound analyses 1 Consider a range of properties 1 Depends on size/area of project... Use parametric variation feature of SHAKE2000 in some cases 2 No 1 Not at this time. 1 Sometimes use ±20% or so for soil properties, depending upon the application. 1 Vary the Vs profile by plus/minus 15 to 20% of the measured Vs 1 We have only had this done by outside consultants (university work) 1 We typically subcontract this to a specialist 1 We use ±20% of the measured shear wave velocities. 1 Yes, but only develop a range of properties and then use engineering judgment. 1 Consider Upper Bound and Lower Bound ground models 1 No consensus on how to account for "uncertainty" 1 Use a range of properties and try different modulus and damping curves 1 Yes, parametric sensitivity studies 1 Some of my research looks at the effect of spatial variability of soils on site response. In this case--we use three dimensional varying soil properties. We specify the spatial variability with geostatistical methods. We have also looked at the effects of small changes in 1-D profiles on ground motions. 1 When SASW and ReMi are used, there is uncertainty and non-uniqueness that has to be dealt with. For example, we use multi-mode consid- erations for inversion process and we use a hybrid dispersion curve using both MASW and ReMi to reduce uncertainties. 1 Uncertainty in soil column is primarily considered for Vs. This is typically varied by 10 to 15% about measured or target values. 1 Use site data on Vs if available. If not available, Toro et al. (1997) model. Use sigma terms on MRD from Darendeli/Menq. 1 Sensitivity analyses for Vs estimates, depth to half space (very hard rock) and Vs contrast at soil­rock interface (impedance effects). 1 Sometimes use various damping and modulus relationships, conduct limited sensitivity analysis on Gmax; this depends on the amount and quality of exploration and soils data and confidence in the input soil parameters. 1 Yes, by RVT and/or ranging the N-SPT across site and determine the Vs based on Vs-N correlation. 1 Yes. The site response analysis will be completed with three Vs profiles: the lower, upper, and best estimate profile based on the soil data and test results obtained at the site. Using the best estimate profile, the different material curves will be used to complete the analysis using one or two earthquake histories. 1 Generally not. The complexity of the many permutations of possible soil property combinations would render the analyses cost prohibitive. 1 Depending on the nature of the project, we may include the lower and upper bounds of the soil properties in our analyses. However, often we only use the best estimate values. For DOE/NRc projects we also do the randomization of the properties and layers. 1 Yes. Monte Carlo realizations using non-Gaussian stochastic fields. Low and large strain properties, depth dependent standard deviation. 1 We will evaluate the upper bound, lower bound and mean in the Vs profile. The variation on Vs is at least ±10% or more if data seem to require. We may also vary the modulus reduction and damping strain relationships. 1 Rarely....only if the budget will allow. If I do, I typically will consider the soil profile as epistemic uncertainty and use a logic tree approach. 1 Yes. Consider the uncertainty by using three soil profiles at best estimate, lower, and upper bounds. 20.) Please include other comments you may have related to the topic of soil profile input TABLE B26 OTHER COMMENTS RELATED TO THE TOPIC OF SOIL PROFILE INPUT Response 1 Georgia is a low risk seismic state and most of this is not required. 1 We typically subcontract this to a specialist. Table B26 continued on p. 63

63 Table B26 continued from p. 62 TABLE B26 OTHER COMMENTS RELATED TO THE TOPIC OF SOIL PROFILE INPUT Response 1 When site response studies are done for nuclear projects, multiple realizations (30 or more) are used to evaluate the uncertainty in Vs, layer location, modulus reduction, and damping curves. We have not done this ourselves. For this work we used Bob Youngs at Geomatrix because of his long involvement in this area. As I note later, you may want to contact Bob and Walt Silva to obtain their views on your ques- tions. An interesting aspect of nuclear projects is that they use equivalent- linear codes, and sometimes they set up soil models that are sev- eral thousand feet in thickness. For these analyses they give a lot of attention to proper definition of damping (kappa) to avoid overdamping the response. This approach has been troublesome to me. We have been reluctant to use models greater than 300 to 400 ft in thickness in our analyses because of uncertainties in damping characteristics. 1 It is important to consider the uncertainties associated to the soil input parameters used in the site response analysis. 1 We rarely have structures that require the level of investigation needed to develop finely tuned soil models. Conservative approximations are satisfactory in most cases. 1 In addition to Vs profile, depth to bedrock, impedance contrast between rock-soil are critical and hard to measure accurately esp. for deep soil such as Jakarta. 1 Use inversion of ground/downhole records to refine layering at field test beds when description available is coarse. 1 It is important to perform either non-invasive or invasive procedures to obtain shear wave velocity of soils. I prefer downhole as you get a better estimate of shear wave velocity as well as SPT. By doing downhole, you can get soil samples and also do laboratory testing of the soil. 1 We have found that small differences in a 1-D soil profile do not have a significant impact--but that 3-D variability can have a significant impact. 1 To the best of my knowledge, the only result taken from the soil profile is the risk of liquefaction. Page Five--Site response analysis 21.) When is an equivalent-linear analysis (e.g., SHAKE or similar program) used or required? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ] Structure type--please specify [ ] Other, please describe: TABLE B27 CONDITIONS WHERE EQUIVALENT-LINEAR ANALYSIS (E.G., SHAKE OR SIMILAR PROGRAM) IS USED OR REQUIRED--DETAILED DESCRIPTION IS PROVIDED NEXT Count Site class 22 Seismic Hazard 13 Structure Type 19 Other 16 Site class dependent--please list site class: Site F Site Class F, or sometimes even for E to lower the seismic design category deep E, F, shallow sites Sd or Se or Sf Site Class F C, D, E, & F. Used together with the nonlinear analysis for E and F with ground shak- ing larger than 0.6 g. Site Class E and sometimes D when soil conditions seem to warrant F Site Class E consisting of soft soils Table continued on p. 64

64 Table continued from p. 63 Site class dependent--please list site class: E or F Typically E, F Site Class F and sometimes Site Class E for soft and critical structures F C-D or better > class C E, liquefiable F Seismic hazard level--please specify: 500 and 2,500 years All hazard levels. Used together with the nonlinear analysis when PGA > 0.6 at soft soil sites When PGA is between 0.1 and 0.5, and depending on project requirements PGA greater than 0.4g PGA > 0.15G See CBC 2010 <0.5 g low hazard <0.4g Seismic Performance Category B Structure type--please specify: "Non-ordinary" structures based on Caltrans SDC guidelines critical facilities high-rise structure (>30 story) All, used together with the nonlinear analysis for structures supported on piles penetrat- ing through soil layers with drastically different strength and stiffness. non-essential bridges Critical or essential bridges or when the cost of mitigation is high Major tall structures over soft soils Critical structures-hospitals, lifeline highway bridges, power plants, waste containment facilities Often used when structural analysis requires time histories Critical or base-isolated structures medium to high importance important structures important structures important structures Other--please describe: That is all we have used so far. We rarely use SHAKE, but if the soils are very susceptible to liquefaction, we have been known to do the analysis, but this is not always the case. liquefiable soils on Jetty Table continued on p. 65

65 Table continued from p. 64 Other--please describe: See ODOT GDM Section 6.5.1.4 Return period of shaking or required performance NA Used when nonlinear or effective-stress not required Rarely NA Structures with fundamental period > 0.5 second over liquefiable soils. ok when strains modest client driven When no water table in profile validation exercises Site Class F (see above); structures that meet the criteria of 2008 Seismic Design Speci- fications for Highway Bridges; and as required by SCDOT personnel. 22.) What soil models do you usually use for equivalent-linear site response analyses (mark all that applies)? [ ] EPRI [ ] Ishibashi-Zhang [ ] Iwasaki [ ] Seed-Idriss Sand [ ] Seed-Idriss Clay [ ] Vucetic-Dobry [ ] Darendeli [ ] Other: TABLE B28 DISTRIBUTION OF EQUIVALENT-LINEAR DYNAMIC SOIL MODEL PROPERTIES USED IN PRACTICE Value Count EPRI 17 Ishibashi-Zhang 6 Iwasaki 3 Seed-Idriss Sand 18 Seed-Idriss Clay 9 Vucetic-Dobry 21 Darendeli 15 Other 10 Other soil models Not sure Others may be considered depending on soil types, or based on lab testing up to the design consultant NA Menq Hardin and Drnevich Table continued on p. 66

66 Table continued from p. 65 Other soil models measured, usually with RCTS locally developed correlated from SPT information 23.) When is a nonlinear total stress (no pore water pressure generation) analysis used or required? [ ] Site class dependent--please list site class [ ] Seismic hazard level--please specify [ ] Structure type--please specify [ ] Strain amplitude--please specify [ ] Other, please describe: TABLE B29 CRITERIA WHERE NONLINEAR TOTAL STRESS (NO PORE WATER PRESSURE GENERATION) ANALYSIS IS USED OR REQUIRED ­ SEE NEXT PAGES FOR DETAILS Count Site Class 15 Seismic Hazard 11 Structure type 10 Strain amplitude--please specify 14 Other 18 Site class dependent--please list site class: Structure type--please specify: Site Class F, or sometimes even for E to lower the seismic design category critical facilities Sd or Se Very tall structure w period > 5 s (> 40­50 story) E&F Essential bridges in liquefiable soils Site Class E deep clay sites or when unusual soil profiles occur--maybe Essential or critical bridges--or where lateral spreading could when shallow rock occurs. be an issue F often used when structural analysis requires time histories E, F important structures F important D, E >D Strain amplitude--please specify: E or liquefiable greater than 1 percent Strain > 1% and used for design of the deep foundation or Seismic hazard level--please specify: below grade structures PGA > 0.6 g at soft sites, PGA > 1 g for stiff sites >1 to 2% PGA > 0.5 to 0.7 strain >1% See CBC 2010 Preferred where shear strain is greater than about 1% > 0.5 g >1 percent high hazard High > 1% > 0.4g large anticipated strain >0.5g >1% Table continued on p.67

Next: APPENDIX C Site Response Analysis Software Software URLs, References, and Use in Highway Engineering Practice as Identified by Survey Respondents »
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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 428: Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions identifies and describes current practice and available methods for evaluating the influence of local ground conditions on earthquake design ground motions on a site-specific basis.

The report focuses on evaluating the response of soil deposits to strong ground shaking.

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