软弱含水砂岩隧道CRD法施工支护变形及受力特性研究  

Research on Support Deformation and Stress Characteristics of CRD Tunnelling Method in Weakly Sandstone Aquifer

作　　者：屈文彬 QU Wenbin(Beijing Construction Engineering Quality Third Test Institute Co.,Ltd.,Beijing 100037,China)

机构地区：[1]北京市建设工程质量第三检测所有限责任公司,北京100037

出　　处：《力学季刊》2022年第4期970-981,共12页Chinese Quarterly of Mechanics

摘　　要：软弱砂岩地层松散,自稳能力差,导致隧道施工极为困难,为研究交叉中隔墙法(Cross Diaphragm,CRD)施工的安全性并为类似工程提供参考,本文采用现场监测及数值模拟方法研究了弱胶结砂岩占比对初支变形与应力的影响,并分析了采用CRD法在弱胶结砂岩地层施工中的安全性.结果表明:隧道左右拱肩处压力值较大,设计中应重视侧压力系数的选取;开挖面为弱胶结砂岩时,初支变形与应力比开挖面为卵石砂土时增大20%~25%;隧道拱肩和拱脚水平收敛值较小,拱顶沉降和拱底隆起值较大,钢拱架内侧应力略大于外侧,但均小于规范规定的安全限值,说明采用CRD法在弱胶结砂岩地层进行隧道施工可以保证衬砌的安全性,研究结果可为类似工程中钢拱架的选型、布置以及支护时机等提供参考.The stratum is loose and steady ability is poor in weakly cemented sandstone aquifer tunnels, making tunnel construction difficult. To study the safety of CRD construction and provide reference for similar projects, the field monitoring and numerical simulation are used to study the influence of the proportion of weakly cemented sandstone on the deformation and stress of the initial branch. The safety of CRD construction method in the weakly cemented sandstone formation is also analyzed. The results show that the pressures at the spandrels of the tunnel are large, and the selection of lateral pressure coefficient should be paid special attention to in the design. When the excavation surface is weakly cemented sandstone, the initial support deformation and the stress are increased by 20 % ~25 % compared with those of pebble sand case. The horizontal convergences of the tunnel spandrel and arch foot are small, and the settlement of arch crown and the uplift of arch bottom are large. The stress on the inner side of arch frame is slightly greater than that on the outer side, but both are less than the safety limit specified in the regulations. It shows that the tunnel construction in weakly cemented sandstone stratum by CRD method can ensure the safety of lining. The research results can provide reference for the selection, layout and support time of the steel arch frame in similar projects.

关 键 词：隧道工程 含水弱胶结砂岩隧道 现场实测 支护变形 受力特性 

分 类 号：U45[建筑科学—桥梁与隧道工程]