岩溶隧道浅埋段施工工法研究

发布时间：2018-08-27 13:07

【摘要】：为满足经济发展与交通建设的需求,在岩溶地区修建隧道工程越来越普遍。虽然现有施工工法可以满足岩溶隧道的修建,但由于当前规范对岩溶隧道施工方案的选择没有详细规定,因此设计人员主要通过经验进行选择,这样容易低估岩溶隧道地质灾害的发生概率,造成塌方、突泥涌水、地表塌陷等工程灾害,甚至威胁到现场施工人员的生命安全。本文以娄底至邵阳铁路扩能改造工程站前工程中张家湾隧道为背景,参考该隧道的设计参数,甄选典型断面,通过弹塑性理论及ABAQUS数值模拟研究了单个隐伏溶洞在隧道洞周不同位置对围岩稳定性的影响,并且结合三台阶法、双侧壁导坑法、CD法(中隔壁法)的施工过程,就岩溶隧道浅埋段的施工工法进行比选,为以后设计施工提供依据。研究内容主要包括以下几个方面：(1)归纳整理张家湾隧道的量测资料,建立回归方程,对隧道围岩沉降和围岩收敛曲线进行拟合,评定了开挖隧道围岩稳定性。(2)基于弹塑性理论研究了隧道开挖后分别处于二次应力状态下和三次应力状态下的塑性区范围,以及溶洞的塑性区范围,以双方塑性区不相接为标准,计算出隧道与溶洞之间安全距离。(3)通过ABAQUS数值模拟软件,基于张家湾隧道DK19+405断面实际工程建立模型,模拟在不同位置单个隐伏溶洞下三台阶法、双侧壁导坑法和CD法对隧道的开挖过程,整理了三种施工全过程中拱顶沉降、地表沉降、围岩收敛、塑性应力场的发展的数据,比选出最佳施工方法。(4)通过ABAQUS数值模拟软件,对三台阶法在90°、45°、-90°单个溶洞的情况下分别进行了施工优化。
[Abstract]:In order to meet the demand of economic development and traffic construction, it is more and more common to build tunnels in karst areas. Although the existing construction methods can satisfy the construction of karst tunnels, since the current codes do not specify the selection of construction schemes for karst tunnels in detail, the designers mainly select them through experience. It is easy to underestimate the probability of geological disasters in karst tunnels, causing engineering disasters such as landslides, water inrush and surface subsidence, even threatening the safety of construction workers. Based on the Zhangjiawan tunnel in the railway expansion and reconstruction project from Loudi to Shaoyang, the typical section is selected according to the design parameters of the tunnel. Based on the elastoplastic theory and ABAQUS numerical simulation, the influence of different positions of a single concealed cave around the tunnel on the stability of surrounding rock is studied, and the construction process of the CD method (middle next door method) combined with the three-step method and the double-side wall guide pit method is studied. The construction method of shallow buried section of karst tunnel is compared and selected, which provides the basis for the design and construction of karst tunnel in the future. The main contents of the study are as follows: (1) summing up and arranging the measurement data of Zhangjiawan tunnel, establishing the regression equation, fitting the settlement and convergence curve of the surrounding rock of the tunnel. The stability of surrounding rock of excavated tunnel is evaluated. (2) based on elastoplastic theory, the range of plastic zone under secondary stress state and cubic stress state after excavation and plastic zone range of karst cave are studied. The safe distance between the tunnel and the cave is calculated according to the criterion that the plastic zone of both sides is not connected. (3) based on the actual engineering of the DK19 405 section of Zhangjiawan Tunnel, the model is established by using the ABAQUS numerical simulation software, and the three step methods are simulated under the single hidden karst cave in different positions. In the excavation process of tunnel by double-sidewall pit guide method and CD method, three kinds of data of dome settlement, ground subsidence, surrounding rock convergence and plastic stress field development during the whole construction process are sorted out, and the optimum construction method is compared. (4) through ABAQUS numerical simulation software, Under the condition of 90 掳45 掳-90 掳single karst cave, the construction optimization of three step method is carried out respectively.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4

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