上海紫都C楼基坑喷锚网(土钉)支护变形控制与稳定性分析

Stability analysis and performance control of shotcrete bolting mesh support of foundation pit of a building in Shanghai

介绍在上海紫都Ｃ楼基坑（深７．１ｍ）成功采用喷锚网（土钉）支护的实例。工程中的支护参数，用极限平衡理论进行分析，用条分法进行校核。并通过动态监测法，反馈到施工过程中，及时调整支护参数。为防止深部滑移，在设计上增加了竖向注浆锚管。最大限度地缩短分层的支护时间，控制施工各阶段边壁变形，保证了基坑边壁的整体稳定。本基坑工程，±０．００处边壁最大水平位移为１．８ｃｍ；－７．１ｍ处边壁最大水平位移为１．１１ｃｍ，地面无裂缝。

This paper introduces an example of shotcrete-bolting-mesh support of foundation pit(7.1m in depth) in Shanghai. Support parameters are analyzed by theory of limit equilibrium and verified by method of slices, and adjusted in time. In order to prevent deep sliding, vertical grouted anchor pipe is adopted. To shorten the construction period, the sidewall deformation is controlled at every construction stage. The wole sidewall stability is ensured. The maxium horizontal displacments of sidewall (7.1m deep) are:1.8cm at elevation ±0.00 and 1.11cm at-7.00 point. Crack is not found on the ground surface.