海太过江通道公路段工作井基坑降水优化设计

Optimal Design of Foundation Pit Dewatering Scheme to the Working Well in Highway Section of the Haitai Crossing Channel

海太过江通道公路段工作井基坑采用悬挂式止水帷幕,其帷幕深度对基坑开挖施工安全有重要影响。根据承压水抽水试验实测数据,采用数值反演法获取了承压含水层相关水文地质参数;基于研究区地层结构特征,建立了三维地下水流运动数学模型,确定了帷幕最优深度、井群位置和降水井数量。计算结果显示,设计的降水方案能够保证施工场地干燥、基坑底部不发生突涌、土体不发生渗透变形和基坑周围沉降量在允许值内。因此,本建议方案优化了承压降水井群,降低了悬挂式止水帷幕深度,节约了降水成本,为设计部门提供了依据和技术支撑。

Suspended impervious curtain is used in the foundation pit of working well in highway section of Haitai River passage,and its curtain depth has an important influence on the safety of foundation pit excavation.Based on the measured data of confined water pumping test,the hydrogeological parameters of confined aquifer are obtained by numerical inversion method.Based on the stratigraphic structure characteristics of the study area,a 3D mathematical model of groundwater movement was established,and the optimal curtain depth,well group location and number of dewatering Wells were determined.The calculation results show that the designed dewatering scheme can ensure that the construction site is dry,the foundation pit bottom does not occur gushing,the soil does not occur seepage deformation and the settlement around the foundation pit is within the allowable value.Therefore,the scheme proposed in this paper optimizes the group of pressurized dewatering Wells,reduces the depth of the suspended impervious curtain,saves the dewatering cost,and provides the basis and technical support for the design department.