Centrifuge Study of the Effect of Permeability and Other Soil Properties on the Liquefaction and Lateral Spreading of Dense Sand

Abstract

A series of centrifuge tests with base shaking were conducted on the 150 g-ton Centrifuge at Rensselaer Polytechnic Institute to study the effect of soil permeability on liquefaction and lateral spreading of dense granular soil deposits. Seven centrifuge models of 24 cm-thick, sloping, fine Ottawa Sand deposits, were built in 1D laminar box and shaken inflight at 25g to simulate a 6 m soil stratum in the field. The models were subjected to uniform sinusoidal cycles of base shaking at 2Hz, with maximum values of the input acceleration ranging between 0.1g and 0.26g. The effect of soil permeability is investigated through two series of tests: 1) five experiments prepared at 45%, 75% and 92% relative densities where water was used as pore fluid; and 2) two experiments prepared at 75% and 92% relative densities using a pore fluid with viscosity 25 times higher than water. Five of the models were over-consolidated to an OCR = 4 before shaking to investigate the effect of over- consolidation on the response. It was found that as expected, increased relative density and increased permeability decreases liquefaction and lateral spreading. The results also show that it is possible for dense and even over-consolidated deposits to experience high pore pressures and full liquefaction when subjected to high intensity/long duration shaking, but with this liquefaction restricted to shallow depths. The results of this investigation are consistent with other centrifuge studies reported in the literature.