Microfabric evolution of coral sand foundations during seismic liquefaction using 3D images

Abstract

Industrial micro X-ray computed tomography (μCT) is applied to link the macroscopic shaking table tests with the microscopic sand particle–pore structure evolution. Based on 3D image reconstruction, the variation in the particle–pore fabric of coral sand during earthquakes was studied. Moreover, the special evolution of coral sand was revealed through a comparative experiment using Fujian sand. The results show that the variation in the coordination number of the coral sand is positively correlated with the excess pore pressure ratio. The uniformity of the pore diameter decreases after earthquakes, and the reduction degree of the coral sand is smaller than that of Fujian sand. This result is related to the irregular shape and larger surface friction coefficient of coral sand particles. This study provides a deeper understanding of the microscopic evolution of coral sand liquefaction.