基于GMS三维渗流模型的基坑减压降水地层沉降特征分析

Analysis of Ground Settlement Characteristics of Foundation Pit Depressurization Based on GMS Three-Dimensional Seepage Model

指出了基坑内减压降水会导致坑内外产生一定的沉降,基坑内可通过水位降深计算地层沉降量,而基坑外部地层沉降特征却难以分析计算,从而可能引发周边环境问题。以上海中学基坑工程为例,基于基坑抽水试验确定场地(微)承压含水层水力联系及其水文地质参数,并利用GMS构建场地水文地质模型,模拟分析了基坑减压降水引起的基坑内外承压含水层水位和地层沉降特征,以检验方案的降水、降压效果及对周边沉降影响,为建筑施工提供行之有效的减压降水水方案。

Decompression and dewatering in the foundation pit will lead to a certain amount of settlement inside and outside the pit.The ground settlement in the foundation pit can be calculated by the water level drawdown,but it is difficult to analyze and calculate the ground settlement characteristics outside the foundation pit,which may lead to environmental problems.Taking the foundation pit engineering of Shanghai middle school as an example,the hydraulic connection and hydrogeological parameters of the site(micro)confined aquifer are determined based on the foundation pit pumping test,and the site hydrogeological model is constructed by using GMS to simulate and analyze the water level and ground settlement characteristics of the confined aquifer inside and outside the foundation pit caused by the decompression and dewatering of the foundation pit,and to test the dewatering and depressurization effect of the scheme and its impact on the surrounding settlement,which provides effective decompression and dewatering scheme for building construction.