THE EVALUATION OF EFFECTS OF SPATIAL VARIABILITY OF SOIL PROPERTIES, SURFACE TOPOGRAPHY AND SPATIAL COHERENCY OF INCIDENT WAVE ON GROUND MOTION AMPLIFICATION : The Case of KUSHIRO J. M. A. Site

Effects of Soil Spatial Variability on Liquefaction Behavior of Horizontally Layered Ground

“…Spectral density functions of the two-dimensional stochastic fields are given as shown in Table 1 by applying the following Wiener-Khinchin theorem 6) .…”

“…In the simulation, the spatial distribution of the SPT N1 value, the shear wave velocity (i.e. shear modulus) and the internal friction angles in the liquefiable deposits are separately taken into account by using sample functions of discretized triangular and exponential stochastic fields 6) in addition to Gaussian one. Simulation results for stochastic models are compared to those for deterministic models by focusing on ground lateral displacement and excess pore water pressure (EPWP) build-up.…”

Spatial Variation and Its Stochastic Modeling of Seismic Ground Motions in Hard Soil Based on Three-Dimensional-Dense-Array Strong-Motion Observation Records

“…The input was taken to be a vertically ascending S-wave with uniform amplitude characteristics and random phase characteristics in the target frequency band. Regarding S-wave velocity heterogeneity in this model, similar to Kanda and Motosaka 6) , exponential correlation functions were used, and two cases were assumed with coefficients of variation (which prescribe the magnitude of the heterogeneity) of 20% and 40%. The correlation distance in the vertical direction was taken as 0.012Vs (m), and the correlation distance in the horizontal direction was taken as 10 times the correlation distance in the vertical direction 6) .…”

“…Regarding S-wave velocity heterogeneity in this model, similar to Kanda and Motosaka 6) , exponential correlation functions were used, and two cases were assumed with coefficients of variation (which prescribe the magnitude of the heterogeneity) of 20% and 40%. The correlation distance in the vertical direction was taken as 0.012Vs (m), and the correlation distance in the horizontal direction was taken as 10 times the correlation distance in the vertical direction 6) . The coefficient of variation of 20% is a slightly larger value than that set in previous studies 6), 7) and 40% is not realistic, but the cases were established in order to confirm the coherency behavior of the relevant site resulting from the heterogeneous structure described later in this paper.…”