Seismic Performance of an Embankment Underlain by a Liquefiable Layer and Supported by Spatially Variable Soil-Cement Wall

Abstract

This paper presents the results of nonlinear deformation analyses of an embankment on a spatially variable, liquefiable foundation soil reinforced with spatially variable soil-cement (SC) wall. The objective is to evaluate the merit of employing stochastic modeling approaches, such as spatially correlated random fields, relative to deterministic analysis with uniform properties for the soil and SC wall. Spatial variability, which is specified by mean, coefficient of variation (COV), and scale of fluctuation (SOF), can significantly influence the seismic performance of soils and embankments. The numerical analysis was first validated using data from a dynamic centrifuge test conducted at the Center for Geotechnical Modeling at University of California, Davis. Analyses were performed for different sets of realization of the foundation soil and SC wall as well as the range of the length and strength of SC wall and peak base acceleration. Simulation results of the stochastic models with spatially Gaussian random field were examined and compared with the results of the experiment with an emphasis on the crest vertical displacement, berm horizontal displacement, and contours of shear strain in the embankment, foundation soil, and SC wall. The results revealed that the representative percentile of unconfined compressive strength (qucs) in the range of 35th–50th percentile needed to be used in a uniform model to estimate the median of crest and berm displacement in spatially variable SC wall-supported embankment.