建筑物密集区浅埋分岔隧道优化CD法施工力学效应研究  

Simulation Study on the Mechanical Effects of Optimized CDMethod for Construction of Shallow Buried Bifurcated Tunnels in Densely Built-up Areas

作　　者：陈扬勇 王江华 李强 冉东傲 靳晓光[3] CHEN Yangyong;WANG Jianghua;LI Qiang;RAN Dongao;JIN Xiaoguang(China Railway Changjiang Traffic Design Group Co.,Ltd.,Chongqing 401121;Chongqing Fengjian Expressway Co.,Ltd.,Chongqing 404600;School of Civil Engineering,Chongqing University,Chongqing 400045)

机构地区：[1]中铁长江交通设计集团有限公司,重庆401121 [2]重庆奉建高速公路有限公司,重庆404600 [3]重庆大学土木工程学院,重庆400045

出　　处：《公路交通技术》2024年第4期148-157,共10页Technology of Highway and Transport

摘　　要：为揭示建筑物密集区浅埋分岔隧道施工力学效应,依托与白帝城长江大桥隧道锚近接的宝塔坪分岔隧道工程,开展优化CD法施工过程三维有限元数值模拟研究。不同循环进尺、先后行洞施工顺序和二次衬砌施作时机等工况下浅埋分岔隧道施工力学数值模拟结果表明:1)隧道开挖进尺与围岩变形和建筑物沉降成正相关关系,对围岩应力影响不明显,隧道选择1.0 m~2.0 m的循环进尺较为合理;2)分岔隧道左、右洞的开挖顺序以及两隧道掌子面距离对围岩变形影响较大,但对建筑物沉降和围岩应力影响很小,施工时应至少将先行洞开挖40 m后再进行后行隧道的开挖;3)隧道二次衬砌施作时机对围岩变形及建筑物沉降有一定影响,对隧道围岩应力几乎没有影响,隧道开挖进尺60 m后施作二次衬砌可行。To reveal the mechanical effect of shallow buried bifurcated tunnel construction in the building-intensive area,a three-dimensional finite element numerical simulation study was carried out to optimize the construction process of the CD method,relying on the Baotaping bifurcated tunnel project,which is close to the tunnel anchor of the Baidicheng Yangtze River bridge.Numerical simulation on the construction mechanics of shallow buried bifurcated tunnel under different cyclic scales,sequential tunnel construction order and secondary lining timing was carried out.The results show that:1)The tunnel excavation scale is positively correlated with the deformation of surrounding rock and the settlement of surface buildings,and the influence on the stress of the surrounding rock is not obvious,so it is more reasonable to choose the cycle scales of 1.0 m~2.0 m for the tunnel.2)The excavation sequences of left and right holes of the bifurcated tunnel,as well as the distance between two tunnel faces have a great influence on the deformation of the surrounding rock,but the impact on the settlement of the building and surrounding rock stress is very small,and the advance tunnel should be more than 40 m construction before the rear tunnel is excavated.3)The timely application of the tunnel lining has a certain influence on the deformation of the surrounding rock and the settlement of the building,but it has almost no influence on the stress of the surrounding rock of the tunnel,and it is feasible to apply lining after 60 m of tunnel excavation.

关 键 词：浅埋分岔隧道 施工力学效应 优化CD法 建筑物密集区 数值模拟 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]