富水地层暗挖通道贴合车站底板下穿施工变形控制技术

Deformation Control Technology of Underpass Construction of Underground Excavation Tunnel Attaching Station Floor in Water Rich Stratum

针对暗挖通道紧邻下穿地铁车站施工引起既有车站发生位移和结构变形,通过联合实施水平冻结加固、结构外地层注浆加固、分区开挖与支护和监测反馈控制,形成一套以注浆与冻结加固相协调,动态监测指导,能实现低扰动开挖的暗挖通道紧邻下穿地铁车站变形控制技术。结果表明,注浆预加固区水平冻结与融沉补偿注浆作业能保证开挖面及周边土体的稳定性,冻结壁保持效果较好;横向不对称分区开挖支护对既有结构扰动较小,洞内变形可控,监测控制值能够保证施,工作业安全。

In view of the displacement and structural deformation of the existing station caused by the construction of the undergound excavation tunnel adjacent to the underpass subway station,the horizontal freezing reinfocement,grouting reinforcement of the outer layer of the structure,divisional excavation and support,and mnitoring feedback oontrol were jointly implemented.A set of deformation control technology was formed to realize low disturbance excavation of the tunnel adjacent to.the subway station,coordinated by grouting and feeing reinforcement,guided by dynamic monitoring.The monitoring results show that the horizontal freeing and thawing sttlemnent conpensation grouting operation in the gouting pre rinforcement area can ensure the stability of the excavation face and the surrounding soil mass,and the freezing wall has a good retention ffect.The excavation and support of transvense asymmetric zones have less disturbance to the existing structure.The deformation in the tunnel is contollable and the monitoring value can ensure the safety of construction.