上海某地铁站试降水对周边环境的影响分析

Analysis of the Effects of Environments for Dewatering in a Metro Station in Shanghai

通过上海某地铁站的降水试验(明珠3号线高架轻轨距车站端头井基坑的距离只有11 m,对沉降变形的要求为7 mm),研究了第⑦2层承压水层渗透性能、抽水后降水漏斗的形状分布以及降水对地面沉降影响的敏感性;分析了第⑤3-2层作为弱透水层在降水时,因下覆地层水压下降,引起第⑤3-2层孔隙水流失造成土体产生相对较大的固结沉降原因;在详细分析了降水井水位和流量、孔隙水压力、分层沉降量、地表沉降量等各种监测数据的基础上,得到了降水时地面沉降与明珠3号线高架轻轨双柱桥墩基础变形的内在关系。

Based on dewatering testing in metro station in Shanghai （the distance between end well of the pit and Pearl Line 3 is just 11 meters, which deformation is less than 7 millimeters）, Permeability of pressure-bearing water layer （7）2, water drop funnel and sensitivity of ground settlement after dewatering was researched; and the soil consolidation settlement reason caused by void-water pressure was lost in （5）3-2 because of water pressure descend in underlaying soils when dewatering which （5）3-2 was looked as pool permeable stratum. Been analyzing the data of water well level and flux, pore water pressure, layered settlement, total settlement of surface soil and so on in detail, internal relationships between ground settlement and pier foundations defor- mations of Pearl Line 3 was gained. The results offered valuable reference for adjacent buildings influences＇ prediction and pre- vention when foundation pit dewatering gave birth to ground settlement in softy soils.