基于抽水试验的基坑降水引起地面沉降的预测分析

Prediction of Land Subsidence Based on Pumping Test of Foundation Pit

结合上海地区某基坑抽水试验工程,介绍了通过单井和群井抽水试验获得水文地质参数的方法;通过软件建立了三维渗流计算模型并对可能采用的基坑降水方案进行了数值模拟;结果表明:采用的获取水文地质参数的方法合理,建立的数值模型能较好的反映基坑降水的实际情况.最后,基于有效应力原理,通过一维压缩公式,预测了基坑降水引起的基坑内外的地面沉降,为基坑设计和施工提供了环境影响分析的依据.

Combined with a pumping test of the foundation pit engineering in Shanghai,the method to obtain hydrogeological parameters by a single well and group of the well pumping tests was introduced. On the basis of the pumping test results,three- dimensional seepage calculation model was established and the possible dewatering scheme was simulated. The results show that the method to obtain hydrogeological parameters is reasonable,and the seepage calculation model can reflect the actual situation of base dewatering. Finally,based on the principle of effective stress,the ground subsidence was forecasted,caused by inside and outside of foundation pit precipitation. The basis of the environmental impact analysis can be provided for foundation pit design and construction.