软弱砂层下的地铁隧道穿越建筑物的加固技术及注浆控制效果分析

发布时间：2019-03-07 21:13

【摘要】：地铁隧道在富水软弱砂层下穿越建筑物时,容易引起开挖面涌水突泥、围岩滑塌失稳以及建筑物不均匀沉陷等工程灾害。以青岛地铁枣李区间隧道软弱砂层带下穿建筑物工程为例,提出了全断面超前帷幕注浆、初支背后径向注浆及洞内补偿注浆联合加固技术。通过数值计算考虑注浆膨胀作用,分析了隧道下穿施工过程的地表变形及建筑物稳定性特性。研究表明:隧道在软弱砂层中采用全断面超前帷幕注浆会引起地表隆起现象,双线隧道地表呈现M型隆起变形,后开挖隧道变形值较大;地表建筑物在注浆膨胀作用下表现出正曲率变形,后开挖隧道正上方建筑基础最易发生破坏;穿越富水软弱砂层时不能一味提升注浆压力来提高地层刚度,应与现场监测结合进行施工控制。
[Abstract]:When subway tunnel passes through buildings under water-rich and weak sand layer, it is easy to cause engineering disasters such as water gushing and mud inrush of excavation surface, instability of surrounding rock slide and uneven subsidence of buildings, etc. Taking the weak sand layer under the tunnel of Zaoli section tunnel of Qingdao subway as an example, the combined reinforcement technology of full-section advance curtain grouting, radial grouting behind the initial branch and compensation grouting in the tunnel is put forward. Considering the effect of grouting expansion in numerical calculation, the surface deformation and the stability characteristics of buildings during tunnel underpass construction are analyzed. The results show that the application of full-section advance curtain grouting in soft sand will cause the surface uplift phenomenon, the surface deformation of double-line tunnel appears M-shaped uplift, and the deformation value of later excavation tunnel is larger. The surface buildings show positive curvature deformation under the action of grouting expansion, and the building foundation above the tunnel is most likely to be destroyed after excavation. When crossing water-rich soft sand layer, grouting pressure can not be raised to improve stratum stiffness, and construction control should be carried out in combination with on-the-spot monitoring.
【作者单位】：重庆工程职业技术学院建筑工程学院;中铁十一局集团第五工程公司;
【分类号】：U231.3;U455.49

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