软土地区超深基坑引发邻近重要建筑沉降的倾斜注浆主动控制方案——以天津地铁7号线某地下四层站工程为例

注浆常用于基坑引发邻近重要建构筑物变形的主动实时控制，但当注浆与基坑距离较小时，注浆可能会对基坑支护体系造成威胁，目前尚无此方面的有效解决途径。以天津地区某超深地铁车站基坑邻近医院敏感建筑开挖为例，对基坑开挖影响进行分析，在超深地铁车站与医院敏感建筑之间的土层中注浆恢复建筑沉降。因竖直均匀注浆对基坑支护结构有较大不利影响，提出倾斜注浆以减小对基坑的影响。结果表明：倾斜注浆相比竖直注浆对邻近车站基坑的不利影响大幅减小，同时对建筑物沉降控制依然有效；倾斜注浆角度过大在减小建筑物邻近注浆体一侧的沉降时，其他位置会发生较大隆起；增大注浆体顶部埋深能够减弱建筑物隆起现象，使建筑物沉降恢复更加均匀。

Study on active control scheme of settlement of adjacent important buildings caused by super deep subway foundation excavation in soft soil area

When there are sensitive buildings around subway stations, in order to meet the functional requirements of buildings, the deformation control technology of foundation excavation engineering is put forward higher requirements. In this paper, taking the excavation of sensitive buildings adjacent to the foundation excavation of an ultra-deep subway station in Tianjin as an example, the influence of excavation is analyzed, and the settlement of buildings is restored by grouting in the soil layer between the ultra-deep subway station and sensitive buildings in hospital. The settlement of buildings can be controlled by dynamically adjusting the amount of grouting according to the real-time settlement value of buildings and implementing vertical uniform grouting, but it has a great adverse effect on the foundation excavation of adjacent stations. Therefore, it is proposed to reduce the influence of inclined and uniform grouting on the foundation excavation. The grouting effects of different grouting angles and different grouting ranges are analyzed, and the building settlement, station foundation excavation deformation and surface soil settlement after grouting are compared. The results show that when the inclined grouting Angle is too large, the settlement value of the adjacent side of the building will be reduced. Increasing the buried depth at the top of grouting can weaken the surface heave. This study has important theoretical and practical value for the practical project. The control effect of building settlement and the structural deformation of foundation excavation itself are taken as the basis for the evaluation of grouting effect, which is conducive to the selection of the best grouting scheme.