Estimation of nonlinear stress-strain relations in soil layers at different depth on vertical array data
Chang, Chih-Wei
Abstract
The records of the 1995 Kobe and 2000 Tottori earthquakes in JAPAN, during crustal earthquakes with magnitudes Mw ~ 6.7-6.8, were used to estimate the nonlinear stress-strain relations in the soil profiles on vertical array. The records were divided into intervals of 1.5-seconds duration to account for temporal changes in the soil behavior. And the stress-strain relations were assumed to be stationary within each interval, and vary for different intervals. These stress-strain relations can be used to describe the behavior of dense soils at depths below some level (15-25 meter for Kobe and Tottori earthquakes), depending on the composition of the soil layers and their saturation with water, and described by other, more nonlinear stress-strain relations as well as on the magnitude and location of the earthquake. Since the selected best-fit curves are determined by the profiling data, the method allows constructing models of soil behavior in strong motion in various geotechnical conditions and this information can be useful in predicting ground motion in future earthquake. The method can be applied in any site where profiling data are available and an imposed motion can be estimated.
Reference
Olga V. Pavlenko and Kojiro Irikura, Estimation of nonlinear time-dependent soil behavior in strong ground motion based on vertical array data, Pure appl. Geophys., 160, 2365-2379, 2003
Olga V. Pavlenko and Kojiro Irikura, Nonlinear behavior of soils revealed from the records of the 2000 Tottori, Japan, earthquake at stations of the digital strong-motion network Kik-net, Bull. Seism. Soc. Am., 96, 2131-2145, 2006