高地应力条件下软岩隧道掌子面挤出效应研究

发布时间：2018-01-20 20:25

本文关键词： 新意法掌子面挤出超前核心土软岩大变形数值模拟　出处：《西南交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着经济的发展,人口的不断加速增长及城市规模的发展,人类的生存环境持续发生改变,资源利用过度,呈缺乏之势,城市人口增多,人均生存空间减少,交通拥堵,生态失衡和环境恶化等问题对世界经济人文的发展影响越来越恶劣。为此,世界各国政府为了促进社会和经济的发展,解决城市拥挤的问题,逐步开始将城市建设向地下发展,规划建设了一大批地下工程。自新中国成立以来,我国隧道建设已经取得了骄人的成绩,令世界瞩目。新意法是意大利著名学者Pietro Lunardi先生历经多年的探索与实践并在前人理论基础上创立的,又称为岩土控制变形分析法。该工法针对隧道变形反应的真正起因,提出了一整套理论分析方法和实际工程措施。特别是在软弱破碎地质条件下,通过采取预约束和约束措施加固掌子面—超前核心土和隧道围岩,能够实现全断面掘进施工,具有安全、高效、控制工期和费用的优势。本文以兰新高铁第二双线大梁隧道为工程背景,针对高地应力条件下软岩隧道施工过程中存在的掌子面挤出问题,主要完成以下几个方面问题的研究： 1.掌子面挤出做为软岩大变形的主要表现形式之一,要研究掌子面挤出发生的机理首先要明确软岩大变形的发生机理,本文从软岩的定义、软岩大变形的特性及大变形的机理三方面阐述掌子面挤出发生的机理；同时,为了在施工过程中及时有效的预报掌子面是否发生失稳现象,本文提出了简单易用的掌子面挤出预测方法,为现场施工人员及时发现掌子面失稳并采取控制措施提供方法。 2.本论文在第二章部分提出了控制掌子面挤出变形的施工技术,并结合在大梁隧道做得现场试验,通过对比试验结果,比较分析了部分掌子面支护技术对掌子面挤出控制效果,得出了控制掌子面挤出的有效方法；同时,本章内容还提出了掌子面挤出变形的监控量测方法,得到了挤出变形值与掌子面围岩破坏状况之间的关系,为指导施工提供依据。 3.最后,本论文利用大型通用有限差分软件FLAC3D对大梁隧道采用的几种施工工法引起的掌子面挤出变形进行数值模拟,通过对比分析不同施工工法条件下,大梁隧道掌子面的挤出位移值,得出可以有效控制掌子面挤出的施工工法,为挤出性围岩隧道的施工提供依据。
[Abstract]:With the development of economy, the accelerating growth of population and the development of city scale, the living environment of human beings has been changed continuously, the resources are overutilized, and the urban population is increasing, and the living space per capita is decreasing. Problems such as traffic congestion, ecological imbalance and environmental deterioration have more and more bad effects on the development of human culture in the world economy. Therefore, in order to promote social and economic development, governments around the world solve the problem of urban congestion. A large number of underground projects have been planned and constructed gradually. Since the founding of New China, the tunnel construction in our country has made remarkable achievements and attracted the attention of the world. The new idea method was founded by Mr. Pietro Lunardi, a famous Italian scholar, after many years of exploration and practice and on the basis of previous theories. This method is also called geotechnical control deformation analysis method. Aiming at the real cause of tunnel deformation response, this method puts forward a whole set of theoretical analysis methods and practical engineering measures, especially under the weak broken geological conditions. By taking pre-restraint and restraint measures to strengthen the face of the face, the core soil ahead of the tunnel and the surrounding rock of the tunnel, the full section excavation construction can be realized, which has the advantages of safety, high efficiency, control of time limit and cost. In this paper, based on the second double-track large beam tunnel of Lanxin high-speed railway as the engineering background, aiming at the extrusion problem of the face of the soft rock tunnel during the construction of soft rock tunnel under the condition of high in-situ stress, the following aspects are mainly studied: 1. As one of the main forms of large deformation of soft rock, the mechanism of large deformation of soft rock must be defined in this paper in order to study the mechanism of extrusion. The characteristics of large deformation of soft rock and the mechanism of large deformation are discussed in this paper. At the same time, in order to predict the instability of the face in time and effectively in the construction process, this paper puts forward a simple and easy to use method of extrusion prediction of the face of the palm. Provide methods for site construction workers to find out the face instability and take control measures in time. 2. In the second part of this paper, the construction technology of controlling the extrusion deformation of the face of the palm is put forward, and combined with the field test in the beam tunnel, the results of the test are compared. This paper compares and analyzes the control effect of partial face support technology on the extrusion of the face of the palm, and obtains the effective method of controlling the extrusion of the face of the palm. At the same time, this chapter also puts forward the method of monitoring and measuring the extrusion deformation of the face, and obtains the relationship between the value of the extrusion deformation and the failure of surrounding rock of the face of the palm, which provides the basis for guiding the construction. 3. Finally, the numerical simulation of the extrusion deformation caused by several construction methods of beam tunnel is carried out by using the large scale finite difference software FLAC3D. By comparing and analyzing the extrusion displacement of the face of beam tunnel under different construction methods, the construction method which can effectively control the extrusion of the face of the tunnel is obtained, which provides the basis for the construction of the extruded surrounding rock tunnel.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451;U455.49

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