Revisiting the liquefaction resistance of calcareous sand using X-ray CT

Abstract The microstructure of calcareous sand sampled from the South China Sea Islands was investigated using X-ray microtomography (μCT). μCT images directly evidenced the amount of inner pores in the calcareous sand. The image analysis presented a map of the inner pore distribution and volume ratio compared with the volume of solid particles, showing that the inner pore distribution was affected by the particle size. Furthermore, owing to the special structure of calcareous sand particles, crushed particles were observed during cyclic loading, inducing obvious strain and releasing air from the inner pore of the particle, which subsequently desaturated the specimen and increased the liquefaction resistance. This evidence of inner pores in calcareous sand provides another way to examine the undrained response by considering the crushability of the calcareous sand.