含软弱夹层陡倾岩层中地铁车站围岩稳定性研究

发布时间：2018-02-02 18:15

本文关键词： 地铁车站陡倾岩层软弱夹层施工方法围岩稳定性　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：重庆市轨道交通环线莲花村站为暗挖大断面车站,其场地岩层倾角大,且部分地段存在软弱夹层,在此复杂工程条件下研究围岩稳定性很有现实意义。论文以重庆市轨道交通环线莲花村站为依托,采用理论分析、现场监测和数值模拟等方法对陡倾岩层中隧道围岩稳定性进行研究。主要工作及研究成果如下:①在前人研究成果的基础上,总结分析层状岩体的破坏类型及破坏机制,概括出陡倾岩层中常见的5种破坏类型;分析大跨度暗挖车站常用的开挖方法及其优缺点;总结分析软弱夹层特性对围岩稳定性的影响。②根据工程地质条件,建立暗挖车站双侧壁导坑法和三台阶法施工过程的二维有限元数值分析模型,研究围岩的变形和应力特征。分析结果表明:对所研究的工程地段来说,采用三台阶法施工更为科学、合理、快速,在实际施工中也证实了采用三台阶法更适合依托工程。③建立砂质泥岩-砂岩陡倾岩层暗挖车站三维有限元模型,从围岩变形特征、应力特征及塑性区分布特征三个方面,对车站开挖过程中的围岩位移、应力、时间及空间效应进行了研究。分析结果表明:围岩的位移、应力及塑性区表现出明显的非对称性,且在砂质泥岩-砂岩接触面两侧出现位移错动现象。④结合工程实际,设计了六种不同的软弱夹层分布的工况,通过数值模拟分析陡倾岩层中软弱夹层的分布对车站围岩稳定性的影响。分析结果表明:软弱夹层的分布位置对暗挖车站不同部位的围岩位移及应力影响十分明显,这对含软弱夹层的类似工程的设计与施工有很好的指导意义。
[Abstract]:Lianhuacun Station of Chongqing Rail Transit Ring Line is a large section station with large excavation section, with large dip of rock strata and weak intercalation in some parts of the site. It is very important to study the stability of surrounding rock under this complex engineering condition. Based on Lianhua Village Station of Chongqing Rail Transit Ring Line, this paper adopts theoretical analysis. Field monitoring and numerical simulation are used to study the stability of tunnel surrounding rock in steep dip rock strata. The main work and research results are as follows: 1 based on previous research results. The failure types and failure mechanism of layered rock mass are summarized and five common failure types in steep dip rock strata are summarized. The common excavation methods, advantages and disadvantages of long span underground excavation station are analyzed. Summarizing and analyzing the influence of soft intercalation characteristics on the stability of surrounding rock. 2. According to the engineering geological conditions, the 2-D finite element numerical analysis model for the construction process of double-sidewall guide pit method and three-stage method is established. The analysis results show that the three-stage method is more scientific, reasonable and rapid for the engineering section studied. In the actual construction, it is also proved that the three-stage method is more suitable for building the three-dimensional finite element model of sandy mudstone and sandstone steeply dipping station based on engineering .3, and the deformation characteristics of surrounding rock are obtained. In this paper, the displacement, stress, time and space effects of surrounding rock during the excavation of railway station are studied in three aspects: stress characteristics and plastic zone distribution. The results show that the displacement of surrounding rock. The stress and plastic zone show obvious asymmetry, and displacement dislocation on both sides of sandy mudstone sandstone interface. 4. Combined with engineering practice, six different conditions of weak intercalation distribution are designed. The influence of the distribution of weak intercalation in steep dip rock on the stability of station surrounding rock is analyzed by numerical simulation. The results show that:. The distribution position of weak intercalation has obvious influence on the displacement and stress of surrounding rock in different parts of underground excavation station. This is of great significance to the design and construction of similar projects with weak intercalation.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451.2;U231.4

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