摘要
结合北京某地铁区间以极小间距下穿大直径高铁在建盾构隧道工程,采用FLAC3D有限元软件对新建隧道施工预支护过程进行数值仿真,对比深孔注浆与管棚+深孔注浆的复合预支护方案对地层变形、地表沉降及盾构管片变形的影响,结合施工过程监测资料,验证复合支护方案的可行性,结果表明:相比于传统注浆支护方案,复合预支护方案可减少土层及围岩变形约26.2%,降低地表沉降量约30.4%,减少高铁盾构管片径向变形量23.4%。数值仿真分析的高铁建盾构隧道变形规律与实际监测结果一致,最终高铁盾构竖向沉降变形为平均1.555mm。复合支护方案可有效改善地铁隧道区间上部围岩以及土层刚度,大幅提高施工结构及近邻结构的安全性和稳定性。
Combined with the shield tunneling project of a large-diameter high-speed railway under very small spacing in a subway section in Beijing, using the finite element software FLAC3 D to perform numerical simulation to the preliminary support process of the new tunnel construction, comparing the influence of the composite scheme of deep hole grouting and pipe roof + deep hole grouting on stratum deformation, surface subsidence and deformation of shield lining segments, combined with the monitoring data of construction process, verifying the feasibility of composite support scheme. The results show that, compared with the traditional grouting support scheme, the composite pre-support scheme can reduce the deformation of soil layer and surrounding rock by about 26.2%, reduce the surface settlement by about 30.4%, and reduce the radial deformation of high-speed iron shield piece by 23.4%. The deformation law of shield tunnel constructed by numerical simulation was consistent with the actual monitoring results, and the final vertical settlement deformation of shield tunnel of high-speed rail was 1.555 mm on average. The composite support scheme can effectively improve the upper surrounding rock and soil layer stiffness of the subway tunnel, and greatly improve the safety and stability of the construction structure and neighboring structures.
作者
叶成诚
YE Cheng-cheng(Shanghai Civil Engineering Co.,Ltd of CREC)
出处
《智能建筑与智慧城市》
2020年第9期93-96,共4页
Intelligent Building & Smart City
关键词
暗挖
下穿
极小间距
大直径
盾构隧道
underground Excavation
pass underneath
minimal spacing
large diameter
shield tunnel
