FIG. Figure 6.20: Comparison between (a) case 3 (top, Vs = 1000 m/s, 15 Hz, element size = 10m) and (b) case 9 (bottom, Vs = 1000 m/s, 15 Hz, element size = 20m) APPROACH 3, JJJ - Draft A. Preparatory work: 1. Site profile: a. Develop one or more alternative models of the site soil profile from hard rock to TOG and other locations in the soil column; these are denoted base cases. b. Identify physical parameters of the soil profile that are to be treated probabilistically, i.e., uncertain parameters; candidates are depth to bedrock, soil layer thickness, low strain shear moduli or shear wave velocity, low strain material damping, and others; use site specific field data to the extent possible (Chapter 3); multiple degradation curves; c. Identify soil layer properties to be used in equivalent linear analyses, i.e., shear moduli degradation relationships and material damping values for increasing shear strain levels (Chapter 3); use site specific field and laboratory data to the extent possible; SPID says use EPRI curves; 2. Seismic hazard: a. For each annual frequency of occurrence (AFO) (AFO is derived from AFE values and is a function of the assumed increment of AFE in the site response calculation) and each spectral frequency (for some approaches, these frequencies are referred to as frequencies”) at which the seismic hazard was calculated, the seismic “conditioning hazard is deaggregated into source contributors defined by magnitude and distance. b. From recorded motion data individual events corresponding to these magnitude and distance pairs are identified. The ground motion response spectra are assembled to be used in the representation of the candidate events. In addition, for RVT approaches
FIG. Figure 6.20: Comparison between (a) case 3 (top, Vs = 1000 m/s, 15 Hz, element size = 10m) and (b) case 9 (bottom, Vs = 1000 m/s, 15 Hz, element size = 20m) APPROACH 3, JJJ - Draft A. Preparatory work: 1. Site profile: a. Develop one or more alternative models of the site soil profile from hard rock to TOG and other locations in the soil column; these are denoted base cases. b. Identify physical parameters of the soil profile that are to be treated probabilistically, i.e., uncertain parameters; candidates are depth to bedrock, soil layer thickness, low strain shear moduli or shear wave velocity, low strain material damping, and others; use site specific field data to the extent possible (Chapter 3); multiple degradation curves; c. Identify soil layer properties to be used in equivalent linear analyses, i.e., shear moduli degradation relationships and material damping values for increasing shear strain levels (Chapter 3); use site specific field and laboratory data to the extent possible; SPID says use EPRI curves; 2. Seismic hazard: a. For each annual frequency of occurrence (AFO) (AFO is derived from AFE values and is a function of the assumed increment of AFE in the site response calculation) and each spectral frequency (for some approaches, these frequencies are referred to as “conditioning frequencies”) at which the seismic hazard was calculated, the seismic hazard is deaggregated into source contributors defined by magnitude and distance. b. From recorded motion data individual events corresponding to these magnitude and distance pairs are identified. The ground motion response spectra are assembled to be used in the representation of the candidate events. In addition, for RVT approaches
CHAPTERS_1-7__15_Dec_2016_ver_507.docx