论文部分内容阅读
以重庆轨道交通5号线3标里程DK18+138.948~DK18+191.964区间浅埋扁平超大断面隧道工程为依托,对隧道围岩变形及双侧壁导坑法预留核心土开挖合理长度进行研究.采用数值分析软件MIDAS-GTS建立了核心土长度分别为20m、25m、30m隧道三维实体模型,将计算值与现场实测数据进行对比,验证了本文方法的正确性和有效性.通过地表沉降、围岩变形、掌子面附近拱顶下沉、掌子面挤出位移等方面综合分析,最终确定依托工程双侧壁导坑法核心土开挖的合理长度为25m,且不宜大于研究段隧道长度的1/2.本文的方法和结论为此类扁平超大断面隧道核心土留设合理长度问题的研究提供参考,并为施工提供理论支持.
Based on the shallow buried-scale super-large cross-section tunnel project with interval of DK18 +138.948 ~ DK18 + 191.964 in Chongqing Metro Line 5, the reasonable length of core excavation reserved for tunnel surrounding rock deformation and double-sidewall pilot pit method was studied The numerical simulation software MIDAS-GTS has been used to establish three-dimensional tunnel solid core model with core soil lengths of 20m, 25m and 30m, respectively, and the calculated values are compared with the measured data to verify the correctness and effectiveness of the proposed method.Through surface subsidence, The deformation of surrounding rock, the doming of the vault near the face of the palm, the extrusion of the face of the face and so on. Finally, the reasonable length of the core soil excavation based on the double-sidewall pilot pit method is 25m and should not be greater than that of the study tunnel Length of 1 / 2. The method and conclusion of this paper provide a reference for the study of the reasonable length of the core soil of flat super-large section tunnel and provide theoretical support for the construction.