承压水降水引起周边环境变形的粘弹性分析

Viscoelastic Analysis of Surrounding Deformation due to Dewatering of Confined Aquifers

针对上海地区承压水降水引起的地面沉降问题,考虑上海地区软土的非线性渗流变形特征,建立了基坑降水与地面沉降三维粘弹性全耦合数学模型。采用3-D FEM,以上海M4号线董家渡修复工程基坑降水为例,利用抽水实验期间监测资料对计算参数进行了反演,进而对降水运行期间引起的地下水渗流场与地面沉降的变化趋势进行预测,并与实际情况进行了对比,其结果比较吻合。

In order to analyze the land subsidence caused by the necessary dewatering for deep excavation in Shanghai, a 3 - D viscoelastic whole - coupling - model of seepage and stress - strain was established with consideration of the non - linear characters of soft soil in different stress states. By 3 - D FEM, the model was applied to analyze and forecast the distribution and variation of the groundwater flow and strata deformation due to the dewatering of deep confined aquifer in rebuilding the Dong - Jia - Du Tunnel of metro line 4. According to the measured data obtained during the field pumping tests, the parameters were determined by back analysis and then applied to simulate and forecast the distribution of groundwater flow and land subsidence fields during the succession dewatering of deep confined aquifer. It seemed that the calcalation results were nearly in accordance with the measured data.