浅埋软弱围岩隧道变形特征研究  

Deformation Characteristics of a Shallow Tunnel in Soft Rock

作　　者：任育珍 杜俊[1] 张伦华 毛宁 吴涌 REN Yuzhen;DU Jun;ZHANG Lunhua;MAO Ning;WU Yong(China Railway Southwest Research Institute Co. Ltd., Chengdu 611731)

机构地区：[1]中铁西南科学研究院有限公司,成都611731

出　　处：《现代隧道技术》2018年第2期84-90,95,共8页Modern Tunnelling Technology

摘　　要：软弱围岩隧道受开挖扰动影响变形明显,施工中若稍有不慎,就会导致隧道塌方。文章以厦门莲岳隧道A匝道隧道为工程背景,结合隧道所处地质条件,采用数值模拟和现场监测相结合的方法,对浅埋软弱围岩隧道变形特征进行了研究。结果表明,对于软弱围岩隧道,不论是全断面开挖还是台阶法开挖,掌子面挤出位移最大,拱顶下沉和地表沉降次之,洞周收敛最小;隧道围岩变形可以分为掌子面前方的先行变形和掌子面后方变形,围岩条件越差,先行变形越大,约占总变形的10%~30%;采用台阶法等分部开挖工法,可减小对掌子面前方围岩的影响范围及变形。在对浅埋软弱围岩隧道的周边环境有严格变形控制要求时,要采取更为严格的预加固措施来控制隧道施工引起的围岩变形,以确保隧道施工及周边环境的安全。A tunnel in soft rock is affected by construction disturbances and the deformation is very obvious, with tunnel collapse occurring if any mistake is made. Based on the branched tunnel A of the Lianyue tunnel in Xiamen and the geological conditions, the deformation characteristics of the shallow tunnel in soft rock is studied by numeri- cal simulation and site monitoring. The results show that the order of deformation magnitude is： extruded displace- ment at the work face, crown settlement, surface displacement and convergence around the tunnel for a tunnel in soft rock by full-face excavation or the bench construction method. Surrounding rock deformation is divided into ante- cedent deformation in front of the work face and deformation at the rear of the work face, and the more unfavorable the surrounding rock the larger the antecedent deformation, with antecedent deformation occupying 10%-30% of the total deformation. Bench construction reduces the affected scope and deformation in front of the work face. More strict pre-reinforcement measures should be taken to control deformation caused by tunnel construction if more strict requirements for control of surrounding deformation of the soft rock tunnel are specified, in order to ensure the safety of tunnel construction and its surroundings.

关 键 词：浅埋 隧道 软弱围岩 变形特征 

分 类 号：U456.31[建筑科学—桥梁与隧道工程]