温州地铁软土明挖基坑变形监测及数据分析

Monitoring Technology of Mechanicaldeformation of Open Pit in Soft Soil of Wenzhou Railway

针对温州地区特殊条件,通过收集温州地铁眀挖深基坑地下连续墙作为围护结构的深基坑工程实测数据,从统计学角度分析了地下连续墙顶竖直位移、墙体深层侧向位移、地表沉降、支撑轴力等随基坑开挖及时间的变化规律。主要结论如下:(1)墙顶水平位移在支撑设置后均有回弹变形趋势,变形受支撑架设、预加轴力及拆除影响较大;(2)地下连续墙侧向位移随深度均呈"胀肚型"变化趋势,两者最大侧移均发生在埋深中部区域;(3)地下连续墙在基坑开挖初期,受支撑设置影响,地表先小幅隆起,且沉降明显偏大,且不同距离处差异沉降在基坑开挖后期均有增大趋势。

According to the special conditions of Wenzhou area,through the collection of the Wenzhou subway incidentally dig deep foundation pit of underground continuous wall in deep foundation pit engineering test data of the retaining structure,from the perspective of statistics analysis of the top vertical displacement,lateral displacement,deep wall surface settlement and axial force with the excavation and the time variation of underground continuous wall.The main conclusions are as follows:(1)the wall top rebound,vertical displacement of subsoil and the weight of the structure are closely related;(2)the lateral displacements on lattice shaped and conventional diaphragm walls tend to‘bulging belly'style,and the maximum lateral displacement on both kinds of walls can be found in the central region of buried depth;(3)the underground continuous wall in the initial excavation,supported by the effects of surface,a slight uplift.And the settlement is too large,and at different distances from the differential settlement were increased in foundation pit excavation.