SMW工法桩与锚索支护体系地表沉降变形分析

Analysis of Ground Settlement Caused by SMW Process Pile and Anchor Support System

研究目的:基坑开挖引起的土体移动会使得周边建(构)筑物发生不同程度的附加变形,并对环境造成影响。本文通过杭州火车东站通道基坑现场实测数据与理论计算数据的对比,分析了SMW工法桩加预应力锚索的支护体系引起远坑壁处产生过大竖向沉降的原因,希望能为类似支护设计选型、施工提供指导意见。研究结论:基坑隆起、围护墙位移、锚索施工、降水及坑中坑未及时支护等是引起周边地表沉降变形过大的原因,其中,锚索施工影响较大,同时提出SMW工法桩加预应力锚索支护体系在杭州地区合理可行,但在基坑周边邻近有被保护建筑时,应严格控制锚索施工的影响,减少对土体扰动,较好地控制变形。

Research purposes ： The soil movement caused by the excavation of foundation pit can produce the additional deformation of the surrounding building and structure in varying degrees and influence the environment. In this paper, based on the comparison of the actually monitored data with theoretical calculation data of the passage foundation pit of Hangzhou Railway Station, the analyses of the reasons for big vertical ground settlement of the far pit wall caused by SMW process pile and anchor support system are made for the purpose of the reference to the design and construction of the similar support. Research conclusions： The rise of the foundation pit, displacement of protected wall, anchor cable engineering, precipitation and untimely support the pits in foundation pit are the major reasons for producing the big settlement and deformation of the surrounding ground, and the anchor cable engineering hasthe biggest influence. However, the SMW process pile and anchor support system are available for Hangzhou area, but if there is a protected buildings near the pit, the influence of the anchor system should be controlled strictly to reduce the disturbance of the soil and control the deformation.