不同卸荷路径下软土变形特性试验研究

本文通过不同的试验方式对软土进行了不同卸荷路径下的变形特性试验研究。一维压缩回弹试验成果表明，软土的回弹变形随着预压荷载的增大而增大，但与卸荷过程中的卸荷比无关；土样再加荷时的压缩模量小于回弹模量而大于初始压缩模量；得到回弹孔隙比、回弹模量的计算公式，从而计算基坑开挖引起的回弹变形量。三轴卸荷蠕变试验成果表明不同的卸荷路径得到不同性质的蠕变变形；卸荷变形模量随应力路径、时间、荷载的变化而变化。

Experimental study on the deformation of soft soil under different unloading paths

Based on different test methods, the deformation characteristic of soft soil is researched by different unloading stress paths. One-dimensional compression-rebound test results show that the rebound deformation of soft soil increases with preloading, hut has no relationship with unloading ratio. When the soil is reloaded, the compression modulus is less than the rebound modulus but greater than the initial compression modulus. The calculation formula of rebound void ratio and rebound modulus is obtained so that the rebound deformation can he calculated in the foundation pit excavation. The triaxial unloading creep test results show that the different unloading path gives different properties of creep deformation; unloading deformation modulus varies with stress path, time and loading.