深基坑工程预降水诱发地表沉降分析

Analyses on Ground Settlement Induced by Pre-precipitation in Deep Foundation Pit Project

为了预测深基坑工程施工前预降水诱发的地表沉降量,考虑到不同含水率状态下土体重度存在差异,应用大井法基坑降水原理,基于有效应力原理和一维固结压缩理论,计算降水区域单元土体的固结压缩量;并通过随机介质理论方法预测基坑周围的地表沉降量。以某基坑降水施工为背景,理论计算结果显示:预降水导致基坑南侧5 m处地表沉降量达28. 56 mm;降水影响范围为80 m;与现场实测值对比显示两者误差小于10%,验证了研究思路的合理性。

In order to predict the ground settlement induced by pre-precipitation before construction of deep foundation pit.It was considered that the difference density of soil under different moisture content,used the principle of big well method foundation pit precipitation,based on effective stress theory and one-dimensional consolidation theory,the amount of unit soil consolidation and compression in the rainfall area was calculated.The ground settlement around the foundation pit was predicted by the stochastic medium theory.Taking the foundation pit dewatering construction as the background,the theoretical calculations show that the ground settlement caused by pre-precipitation at 5 m on the south side of the foundation pit wall reach 28.56 mm,and the influence range of precipitation is 80 m.Compared with the field monitoring data,the results show that the error is less than 10%,which verify the rationality of the research ideas.