Microstructure analysis on the dynamic behavior of marine clay in the South China Sea

The aim of this article was to study the dynamic behavior and microstructural variation of undisturbed marine clay from the South China Sea. First, dynamic cyclic triaxial tests were employed to investigate the dynamic stress–strain-pore pressure paths of the undisturbed clay. Then, scanning electron microscopy and mercury intrusion porosimetry were used to measure the variations of the micromorphology and pore size distribution between before and after the dynamic cyclic tests. Through these tests, the dynamic failure process and microstructure variation of the marine clay were quantitatively analyzed. In particular, their relationships are qualitatively established from the macro-micro perspective. Furthermore, by comparing the tests of the remolded clay with those of the undisturbed marine clay, the influence of the microstructure on the dynamic behavior is systematically investigated. The results show that the microstructural variation of the marine clay is caused by the compression deformation of the mesopores among the granular clusters into the small pores between individual particles. The study provides an effective reference for the selection of the microstructural parameters of marine clay.