土体卸荷回弹实验研究

Experimental study on the rebound of clay under unloading

通过大量室内固结回弹实验,研究了天津市区土样在卸荷作用下的变形特性。在分析了回弹率和卸荷比以及回弹模量和卸荷比的关系后,确定土样卸荷产生回弹的临界卸荷比R=0.2以及产生强回弹的卸荷比R=0.9。从而可以估算卸荷最大影响区及强回弹区的深度范围,对基坑等卸荷类工程的设计和施工具有一定的指导意义。

Deformation characteristics of soil samples in Tianjin city under unloading are studied through a large number of indoor consolidation - rebound tests. The critical unloading ratio R = 0.2 where rebound happened and the unloading ratio R = 0.9 where strong rebound happened are confirmed after analyzing the relationships of rebound ratio- unloading ratio and rebound modulus - unloading ratio. These two ratios can be used to estimate the depth of unloading influence area and strong rebound area. Therefore, the study in this paper can provide some guidance to design and construction in such unloading projects as foundation pit.