临近地铁车站深基坑开挖综合控制研究

Integrated Control of Deep Excavation nearby the Subway Station

对基坑工程而言设计是源头,施工质量是保证,均应给予重点关注。本文对紧邻苏州轨道交通一号线星海街站的苏州凤凰国际书城基坑工程做了详细介绍,从设计及施工的角度论述在基坑开挖过程中所采用的各种方法,结合实测结果证实其有效性。结果表明:边桁架设置栈桥的围护桩深层水平位移最大值点深度与挖深比值在0.51～0.65H之间,明显小于非栈桥区的实测值,在桩顶位置设置滑移支座进行近似计算较为合理;利用空间效应可有效控制围护桩深层水平位移量,但时间效应影响不明显;坑底及坑内加固可控制围护结构位移量,并能减少桩体的缩颈、扩孔等现象;与原有地铁站止水帷幕搭接来切断微承压水径流补给是可行的。该结论可为此类工程提供参考。

Design and construction are the keys to deep excavation. A detailed introduction of Suzhou Phoenix International Super Bookstore adjacent to Xinghaijie subway station is given. Different methods of excavation during the process of design and construction of deep excavation are tested with measurements. The results show that the depth of maximum value of deep horizontal displacement of the pile is about 0.51 ～ 0.65H in trestle, which is much less than that at the place without trestle and it is reasonable to have calculation by setting the sliding support at the pile top. It＇ s a good method to control the displacement of retaining pile by space effect, while time effect has limited impact, the reinforcement inside and at the bottom of the pit also can be used to control necking and reaming. It＇ s feasible to connect the waterproof curtain of the retaining pile at subway station to cut off the supply of water runoff. The research result is useful to the similar engineering.