Cyclic and Post-Cyclic Behaviors of Stabilized Sand-Containing Soft Soil in Coastal Areas

Abstract

Land resources are being depleted due to global climate change, and as a result, infrastructures such as expressways and high-speed railways have no option but to be built in soft soil regions. Hence, the cyclic and post-cyclic behaviors of soft soil are vitally important. However, little attention has been devoted to this issue. In the current study, a series of cyclic triaxial tests and standard monotonic loading tests were carried out in order to investigate the cyclic and post-cyclic behavior of stabilized sand-containing soft soil. In addition, the stiffness evolution index model was proposed to describe the characteristics of stiffness evolution. The results show that for a given number of loading cycles, stiffness almost linearly decreases with the increase in sand content. The higher the confining pressure is, the greater the stiffness is. The cement content has the greatest impact on the stiffness evolution index. The stiffness evolution index model can provide a good description of experimental data. The initial value of post-cyclic axial strain is non-zero due to the accumulative strain caused by previous cyclic loading. Post-cyclic stress increases rapidly within a small range of strain and can reach peak stress with great speed. The post-cyclic initial tangent modulus increases from 1602 kPa to 4803 kPa as the cement content increases from 6% to 12%.