软土基坑开挖引起的坑外地表沉降预测数值分析

通过对基坑开挖过程的有限元数值模拟可知，当围护结构发生正向、反向转动及挠曲等3种基本变形模式时，坑外地表沉降分布具有较为明显的规律，均可采用统一格式的指数曲线进行模拟，即可得到坑外地表沉降曲线的经验公式。利用正向、反向转动及挠曲等3种基本变形模式对围护结构的任意变形模式进行拟合，求得3种基本模式的最大位移值，然后根据3种基本模式所对应的坑外地表沉降经验公式，求得每一基本模式所对应的坑外地表沉降分量，并进行叠加，从而求得坑外地表沉降分布曲线。

Numerical analysis of estimation of ground surface settlement outside pit induced by soft-soil excavation

The numerical simulation of the excavation shows that,for each basic deformation modes of the retaining wall,for example the forward rotation,reverse rotation and deflection,distribution of the ground surface settlement outside pit shows obvious regularity,which can be fitted by the exponential curve with a unified format,then the empirical formulas are got.Arbitrary deformation mode of the retaining wall can be fitted using the three basic deformation modes above,and the maximum displacement value for each basic deformation mode can be obtained.Using the empirical formulas above,the corresponding ground surface settlement for each basic deformation mode can be calculated.Then superimpose the settlement and obtain the distribution curve of ground surface settlement.