陡倾含软弱夹层围岩隧道初期支护可靠度研究

发布时间：2018-01-19 09:46

本文关键词： 可靠度初期支护不确定性失效模型设计验算点法　出处：《重庆大学》2016年硕士论文　论文类型：学位论文

【摘要】：国内外学者对结构可靠度的研究已有70多年的时间,取得了很多研究成果。然而对于地下空间建(构)筑物的可靠度研究仍处于不断的探索之中。尤其在特殊地质条件下,如何建立合适的结构失效模型,构造合理的功能函数还存在广阔的研究空间。本文依托重庆轨道交通环线莲花村地铁车站,通过地铁车站施工过程的监控量测和有限元数值模拟,动态跟踪车站隧道周边位移和应力的变化,构建隧道初期支护的失效模型。通过对影响隧道结构功能函数中抗力和作用效应的不同影响因素(包括材料参数、几何参数的不确定性)的统计分析,采用设计验算点法计算地铁车站初期支护的可靠度。本文主要的研究内容如下:(1)基于含软弱夹层陡倾岩层中大跨度地下车站施工过程的监控量测数据和MIDAS/GTS有限元模拟的结果,对比分析监测点和对应模拟点的位移和应力变化规律,建立含软弱夹层陡倾岩层地铁车站初期支护的失效模型。(2)通过分析作用在初期支护上的地层压力变化特征,重点计算不同荷载理论下围岩的压力值,结合数值模拟计算结果,选择合适的围岩压力计算值,将围岩压力值折减为线性荷载,将其等效为剪切作用。(3)在分析层状岩层地下工程初期支护破坏形式的基础上,建立初期支护的失效模型功能函数,对功能函数中涉及的材料性能和几何参数的不确定性进行统计分析。(4)依据可靠度的串并联理论,结合地铁车站建设的工程实践,提出采用折减系数来研究初期支护的可靠性指标;选择较为实用的结构可靠度计算方法—设计验算点法,计算地铁车站初期支护的可靠指标。
[Abstract]:Scholars at home and abroad have been studying the structural reliability for more than 70 years. Many achievements have been made. However, the reliability of underground space structures is still under continuous exploration. Especially in the special geological conditions, how to establish the appropriate structural failure model. This paper relies on the Lianhuacun subway station of Chongqing rail transit ring line, through the monitoring measurement and finite element numerical simulation of the construction process of the subway station. Dynamic tracking the changes of displacement and stress around the tunnel and constructing the failure model of the initial support of the tunnel. Through the influence of different factors (including material parameters) in the function function of the tunnel structure. Statistical analysis of the uncertainty of geometric parameters. The reliability of initial support of subway station is calculated by design checking point method. The main research contents of this paper are as follows: 1). Based on the monitoring data of large span underground station construction process and the result of MIDAS/GTS finite element simulation. The law of displacement and stress change of monitoring points and corresponding simulation points are analyzed and compared. The failure model of initial support of subway station with weak intercalation and steep dip rock layer is established. By analyzing the characteristics of formation pressure variation acting on the initial support, the stress value of surrounding rock under different load theory is calculated. Combined with the numerical simulation results, the appropriate value of surrounding rock pressure is selected, and the value of surrounding rock pressure is reduced to linear load. On the basis of analyzing the failure form of initial support in layered rock stratum underground engineering, the function function of failure model of initial support is established. The uncertainty of material properties and geometric parameters involved in the function function is statistically analyzed. (4) according to the theory of reliability of series-parallel connection, combined with the engineering practice of subway station construction. A reduction coefficient is proposed to study the reliability index of initial support. A practical calculation method of structural reliability is chosen to calculate the reliability index of the initial support of subway station by designing the checking point method.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U455.7

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