穿越既有采空区隧道施工控制技术

发布时间：2018-01-30 09:43

本文关键词： 铁路隧道数值分析稳定性控制技术　出处：《石家庄铁道大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国交通建设的进展，近接采空区的公路隧道、铁路隧道不断涌现，如何确保近接采空区工程的施工安全和运营安全逐渐成为工程界所面临的崭新课题。当新建隧道遇采空区地段时，面临的危害主要有：(1)新建开挖施工振动造成既有采空区岩板或岩柱失稳，导致开挖洞体坍塌；(2)采空区的存在改变了原始地应力分布状态，导致隧道结构受力不均，易引发新建隧道局部开裂；(3)采空区长期残余变形引发新建隧道不均匀沉降，严重影响列车运行安全和隧道结构耐久性等。因此本文以娄邵铁路扩能改造工程中的明清堂隧道为工程背景，基于穿越既有采空区隧道施工控制技术，主要进行了以下几个方面的研究工作： (1)根据明清堂隧道钻探资料显示，新建隧道多遇下伏隐伏采空区和上伏露天采空区，为分析采空区对隧道施工效应的影响程度，本文添加了隧道存在上侧和单侧隐伏采空区，以及隧道存在单侧露天采空区几种情况，从洞周位移、地表沉降、支护内力和塑性区分布四方面通过比较分析结合实际施工情况综合确定适合明清堂隧道的施工方法；确定施工方法后，又分析了不同距离采空区下采用该法的隧道开挖模拟，确定该法是否继续适用。 (2)采用突变理论评价采空区与隧道间岩层的稳定性，通过研究采空区与隧道间岩层系统的总势能，建立岩层失稳的突变模型，分别推导出了隧道底部含隐伏采空区、顶部含露天采空区时岩层突变失稳力学条件和安全距离计算公式，并依据岩体参数算出了顶板最小安全厚度值，，与数值模拟结果进行了对比分析，并给出了不同参数下采空区顶板的最小安全厚度值；推导出了考虑动力荷载影响下的采空区与隧道间岩层突变失稳的力学条件和安全距离计算公式；最后推导出了可能出现的采空区与隧道间岩层类似于岩柱的突变失稳力学条件和安全距离计算公式，为采空区地段隧道工程设计和施工提供了理论依据。 (3)根据明清堂隧道的工程特点，总结了采空区在安全距离下隧道施工控制技术、近距离下采空区隧道施工控制技术和既有采空区处治、加固措施三方面内容，为工程顺利施工提供了一定的保障。
[Abstract]:With the development of traffic construction in our country, the highway tunnel near goaf and railway tunnel emerge constantly. How to ensure the construction safety and operational safety of the near goaf project has gradually become a new topic facing the engineering field. When the new tunnel meets the goaf section. The main hazards are: (1) the vibration of new excavation results in rock slab or pillar instability in the existing goaf, which leads to the cavern collapse; (2) the existence of goaf changes the original distribution of in-situ stress, which leads to the uneven force of tunnel structure and local cracking of newly built tunnel. The long term residual deformation of goaf leads to uneven settlement of newly built tunnels. Seriously affect the safety of train operation and the durability of tunnel structure. Therefore, this paper takes the Ming and Qing Tang Tunnel in the Loushao Railway capacity expansion Project as the engineering background, based on the tunnel construction control technology through the existing goaf. The main research work is as follows: 1) according to the drilling data of the Ming and Qing tang tunnel, the underground goaf and the open-pit goaf are often encountered in the new tunnel, in order to analyze the influence degree of the goaf on the tunnel construction effect. In this paper, the existence of the tunnel in the upper side and unilateral hidden goaf, as well as the tunnel has unilateral open-pit goaf several cases, from the hole around the displacement, surface settlement. Four aspects of the distribution of supporting internal force and plastic zone are compared and combined with the actual construction conditions to determine the construction method suitable for the Ming and Qing Tong Tunnel. After the construction method is determined, the tunnel excavation simulation using this method in different goaf is analyzed, and it is determined whether the method will continue to be applicable. Secondly, the catastrophe theory is used to evaluate the stability of rock strata between the goaf and the tunnel. By studying the total potential energy of the strata system between the goaf and the tunnel, the catastrophe model of rock strata instability is established. The mechanical condition and safety distance calculation formula of sudden instability of rock strata with hidden goaf at the bottom of the tunnel and open-pit goaf at the top are derived, and the minimum safe thickness of roof is calculated according to the rock mass parameters. Compared with the numerical simulation results, the minimum safe thickness of the goaf roof is given under different parameters. The mechanical condition and safe distance calculation formula of sudden instability between goaf and tunnel are derived considering the influence of dynamic load. Finally, the mechanical condition of sudden instability and the formula of safety distance between the strata of goaf and tunnel are deduced, which provides the theoretical basis for the design and construction of tunnel in goaf. According to the engineering characteristics of Ming and Qing tang tunnel, the construction control technology of goaf in safe distance, the construction control technology of goaf tunnel in close distance and the treatment of existing goaf are summarized. Three aspects of reinforcement measures provide a certain guarantee for the smooth construction of the project.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.49

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