基坑开挖引起变形的简化预测方法

A Simplified Method for Predicting the Deformation Induced by Pit Excavation

以带有半圆形基坑开挖边界的弹性半平面应力解为基础,根据重量等效原则,推导实际工程中常见的矩形基坑开挖边界的弹性半平面应力解.采用广义虎克定律,推导坑底回弹量估算公式,以及基坑周围土体的竖向位移和水平向位移估算公式,并采用plaxis有限元软件进行建模分析验证该估算公式的合理性.最后将文中提出的估算方法的计算结果与工程实测数据及按简单视为等重量卸荷的分层总和法等传统估算方法结果进行对比,进一步验证该估算方法的合理性.

According to the rule of equivalent weight, based on the elastic semi-plane stress with semicircular excava- tion boundary, this study predicts the stress with rectangular excavation boundary which is common in the actual pro- jects. Hooke＇s law can be adopted to deduce the estimating formula of pit bottom resilience and the formula about the vertical displacement and horizontal displacement of the soil mass around the pit bottom. And the ultimate data can be compared with that of the finite element method. At last, the data obtained through this method is compared with that of the traditional method, such as the test data and the data deducted by the layer-wise summation method, to vali- date the rationality of this method.