吉图珲高铁东兴隧道膨胀岩场地预留土柱施工方法研究

发布时间：2019-01-27 21:37

【摘要】：近些年来，伴随高速铁路的快速发展，复杂地质条件下铁路隧道的修建和维护日趋频繁，这期间由于膨胀性软岩导致的工程问题屡见不鲜。据统计，全球40多个国家和地区的隧道工程都遭受过不同程度的膨胀岩问题，并且造成了不小的经济损失。我国则主要出现在广西、云南、河南、湖北、四川、陕西、河北、安徽、江苏和吉林等地。因此，开展对特殊岩土环境下隧道开挖问题的研究，提出适用于膨胀性软岩隧道施工的快速开挖支护方法是具有现实意义的。本文针对吉图珲高铁东兴隧道膨胀岩场地的开挖问题，分析了东兴隧道工程地质和水文地质资料，得到了地层分布特征和主要物理力学参数。同时，，研究了东兴隧道场地不同深度同一位置和不同位置同一深度膨胀性围岩的自由膨胀率试验结果，得到了该场地膨胀岩土的分布规律。此外，阐述了东兴隧道的既有施工方法和棘手的工程问题，提出了一种适用于膨胀岩土场地的新型隧道施工方法——预留土柱法（SRD法）。在此基础上，采用二维和三维有限元方法比较分析了交叉中隔墙法和预留土柱法，并对预留土柱法的主要施工参数进行了研究，其具体内容如下：（1）建立交叉中隔墙法和预留土柱法的二维有限元模型，比较分析了不同开挖方法对地表沉降、拱顶沉降、水平收敛、塑性区分布和支护结构内力等方面的影响。（2）建立预留土柱法的二维有限元模型，改变开挖顺序、土柱宽度和曲率等主要施工参数，研究了不同参数变化对地表沉降、拱顶沉降和水平收敛的影响。同时，建立三维有限元模型，针对6m、12m和15m三种台阶长度，研究了其对超前掌子面、滞后掌子面、隧道纵向地表沉降和拱顶沉降等方面的影响，给出了预留土柱法最优施工参数的取值范围。基于以上分析，介绍了预留土柱法的施工性态，并验证了采用预留土柱法进行隧道开挖的可行性和优点，为膨胀性软岩场地隧道开挖问题提供了一定的参考。
[Abstract]:In recent years, with the rapid development of high-speed railway, the construction and maintenance of railway tunnels are becoming more and more frequent under complex geological conditions. During this period, engineering problems caused by swelling soft rock are common. According to statistics, more than 40 countries and regions in the world have suffered different degrees of dilatation rock problems, and caused no small economic losses. China mainly appears in Guangxi, Yunnan, Henan, Hubei, Sichuan, Shaanxi, Hebei, Anhui, Jiangsu and Jilin. Therefore, it is of practical significance to carry out the research on tunnel excavation in special geotechnical environment and to put forward a rapid excavation support method suitable for the construction of expansive soft rock tunnel. In this paper, the engineering geological and hydrogeological data of Dongxing tunnel are analyzed, and the distribution characteristics of strata and main physical and mechanical parameters are obtained, aiming at the excavation of expansive rock site in Dongxing Tunnel of Jituhui High Speed Railway. At the same time, the experimental results of the free expansion rate of the expansive surrounding rock at the same depth and at the same depth are studied, and the distribution law of the expansive rock and soil is obtained. In addition, the existing construction methods and difficult engineering problems of Dongxing Tunnel are expounded, and a new method of tunnel construction suitable for expansive rock and soil sites, i.e., reserved soil column method (SRD method), is put forward. On this basis, two dimensional and three dimensional finite element methods are used to compare and analyze the cross middle partition method and the reserved soil column method, and the main construction parameters of the reserved soil column method are studied. The main contents are as follows: (1) two dimensional finite element models of cross middle partition method and reserved soil column method are established, and different excavation methods are compared and analyzed for ground subsidence, vault settlement and horizontal convergence. The influence of plastic zone distribution and internal force of supporting structure. (2) the two-dimensional finite element model of reserving soil column method is established. The main construction parameters such as excavation sequence, soil column width and curvature are changed, and the effects of different parameters on surface settlement, vault settlement and horizontal convergence are studied. At the same time, a three-dimensional finite element model is established to study the influence of the three steps length of 6m 12m and 15m on the forehand face, lag palmface, tunnel longitudinal surface subsidence and dome settlement, etc. The range of optimal construction parameters of soil column method is given. Based on the above analysis, the construction behavior of reserving soil column method is introduced, and the feasibility and advantages of tunnel excavation by reserving soil column method are verified, which provides a certain reference for tunnel excavation in expansive soft rock site.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.4

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