地铁盾构隧道下穿既有铁路变形控制研究

盾构隧道下穿既有铁路线路会造成铁路线路沉降变形，影响列车的正常运行。基于此，在某实际工程的基础上，对地基加固、盾构下穿过程中铁路线路沉降情况进行监测分析。结果表明：旋喷桩加固注浆施工对铁路线路影响很小，当旋喷桩加固施工完成后，主加固区施工对铁路线路影响较大；地基加固对盾构下穿时铁路线路变形控制有较好效果，隧道穿越施工期间，路基最大沉降量为36．52mm，轨面最大沉降量为15．88mm，满足规范要求。

Deformation Control on Shielding for Metro Tunnel beneath Existing Railway Line

Shielding for metro tunnel beneath existing railway line will cause track and surrounding ground surface subsidence and deformation, affecting the normal operation of trains. Based on this, a case study fbr a specific engineering for foundation reinforcement, monitoring and analysis on track and surface subsidence of the shielding underneath engineering process is conducted. The results show that turning shotcret reinforcement construction has little effect on the track. After turning shotcret for pile reinforcement construction is complete, the main reinforcement area construction affects the railway line, so foundation reinforcement has good results on the deformation control. Tunnel passes underneath during the construction, the subgrade has the maximum settlement of 36.52 mm, and the maximum settlement of the track surface is 15.88 ram, which meets the specified requirements.