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8 provided comments on the fourth Interim Report, and view of the seismic loading criteria developed for the Project. these comments have been addressed where possible in this This discussion also covers information on the ground Final Report. motion revisions being proposed at the time (and since adopted) to the current AASHTO LRFD Bridge Design Spec- 1.3 Organization of Final Report ifications, the range of ground shaking levels that new seis- mic maps show, and the variation in response spectra This Final Report is organized into two volumes. The first between WUS and CEUS. The review of seismic loading cri- volume, titled Final Report, is a compilation of information teria is followed by summaries of (1) the Newmark dis- presented previously in the first, second, third, and fourth placement correlations that were developed and (2) the cor- Interim Reports; it is published as NCHRP Report 611. The relation between peak ground velocity (PGV) and spectral second volume, titled Recommended Specifications, Com- acceleration at one second (S1). Information in this chapter mentaries, and Example Problems, presents the proposed serves as basic input data for the following studies. specifications, commentaries, and example problems for Chapter 6--Height-Dependent Seismic Coefficient involves the retaining walls, slopes and embankments, and buried a summary of the results of the height-dependent seismic structures. coefficient that was developed for use in the analysis of re- taining walls, as well as slopes and embankments. This sum- 1.3.1 Volume 1--Final Project Report mary covers effects of ground motion incoherency, referred to as wave scattering analyses, for slopes and for retaining This volume has 10 chapters following Chapter 1 Introduc- walls, and it provides guidance on the intended application tion. These chapters were taken from interim reports prepared of the scattering solutions. as the Project was completed. The Draft Final Report serves as Chapter 7--Retaining Walls describes the current design documentation for the work as it was being performed during process, including the use of the Mononobe-Okabe equa- the Project and provides the basis for information presented in tions and the limitations of this approach. This discussion the recommended specifications, commentaries, and example is followed by a summary of the potential effects of cohe- problems. sive soil content on seismic earth pressures estimated by the Mononobe-Okabe method and a generalized limit- Chapter 2--Data Collection and Review summarizes re- equilibrium approach for determining seismic active earth sults from the literature review for the three principal areas pressures. The next discussions cover results of a study of of development (that is, retaining walls, slopes and em- impedance contrasts and nonlinear effects on seismic design bankments, and buried structures). This summary includes coefficients and the use of a displacement-based design ap- conclusions reached from discussions with individuals rep- resenting selected DOTs, vendors, and consultants regard- proach for gravity, semi-gravity, and MSE walls. The chapter ing the availability of seismic design guidelines for each of concludes with specific comments on the design of gravity the three principal areas of development. and MSE walls and some general guidance on the design of Chapter 3--Problems and Knowledge Gaps involves a dis- nongravity cantilever, anchored, and soil nail walls. Chapter 8--Slopes and Embankments reviews the current cussion of knowledge gaps and problems associated with current design methodologies for each of the three areas. approach used for the seismic design of slopes and em- These knowledge gaps and problems were identified on the bankments. This review is followed by a recommended basis of the literature review and discussions with repre- displacement-based approach for evaluating seismic sta- sentatives from DOTs, vendors, and other consultants bility. The recommended approach provided a basis for summarized in Chapter 2, as well as the Project Team's ex- developing screening methods where no analysis is re- perience on related retaining wall, slope and embankment, quired or where a factor of safety approach is preferred. and buried structure projects in seismically active areas. Chapter 9--Buried Structures covers the recommended Chapter 4--Work Plan: Analytical Methodologies describes approach for the TGD design of buried pipes and culverts. the work plan for developing analytical methodologies that The discussions in this chapter review the general effects of was recommended for addressing the knowledge gaps and earthquake loading and the potential failure modes. A brief problems outlined in Chapter 3. The proposed analytical summary of the seismic design practice is given, and then methodologies included development of methods for quan- the proposed methodology is defined. This methodology tifying the determination of seismic demand, as well as the covers ovaling of circular conduits, racking of rectangular methods used to determine the capacity during seismic load- conduits, and then results of a series of parametric and ver- ing for each area of development. ification studies. Chapter 5--Seismic Ground Motions summarizes results Chapter 10--Recommendations for Future Work summa- from the ground motion studies. These results include a re- rizes a number of topics not resolved during the Project