Analytical and experimental study on shaking effects for improved stone column foundations

Abstract

Stone column technology is a method used to reduce liquefaction in saturated sediments. By using materials with greater permeability than the surrounding soil, stone columns can help drain excess pore water pressure and mitigate liquefaction potential during seismic loading. In this study, analytical solutions are proposed to address the liquefaction problem in saturated soils during earthquakes, taking into account the influence of stone columns and the surrounding soil. These solutions consider the excess pore water pressure at the boundary of the zones and analyze the vertical and horizontal drainages. The study also includes centrifuge tests on sandy soils improved with stone columns, calculating the total seepage flow and converting it into settlement based on the relationship between drainage flow rate and volumetric changes in the soil. The calculated settlement aligns well with the measured value in the centrifuge test, confirming the accuracy of the analytical formula for calculating settlement in stone column foundations. The study also evaluates the combined effects of radial and vertical drainages in stone column foundations using the derived analytical solutions.