硬性结构面对深埋硬岩隧道开挖稳定性影响分析

发布时间：2018-04-03 11:54

本文选题：深埋隧道　切入点：高地应力　出处：《长沙理工大学》2014年硕士论文

【摘要】：随着我国隧道建设向着“长、大、深、群”方向发展,深埋硬岩隧道在硬性结构面控制下的稳定性问题日益受到重视。本文以有限元软件Midas/GTS为分析工具,将深埋硬岩隧洞在结构面控制下的开挖简化为平面应变问题,对结构面自身特性对深埋硬岩隧道稳定性影响,不同岩性条件、不同高地应力下结构面对深埋硬性隧道稳定性影响,以及在自重应力下结构面的尺寸效应做了较全面的模拟试验,并定量地分析了不同情况下硬性结构面对隧道各部位围岩变形、塑性区的影响效果,对相关工程人员的实践有一定的参考价值。本文的主要成果：(1)以围岩变形为主要指标,确定了硬性结构面对深埋硬岩隧道的最大影响距离和有效影响距离,以及结构面特性变化时对隧道围岩变形的影响；(2)分析了岩性变化时结构面对隧道稳定性的影响,表明好的岩性有助于降低结构面的不利影响；反之,差的岩性会使结构面的不利影响增强；并单独分析了岩性参数,发现岩体抗拉强度基本无影响,而弹性模量、内摩擦角、粘聚力以各自方式影响着结构面的作用；(3)分析了不同高地应力形式下结构面的影响作用,表明结构面在侧压系数增加或自重应力增加时,均加剧了隧道的不稳定性；(4)确定了小尺寸结构面在倾角和距离一定时的最不利分布；提出最大有效影响尺寸的概念；分析了结构面在高地应力硬岩条件下的尺寸效应,得出在结构面有效影响距离内的最大有效影响尺寸与倾角、距离的关系式,并通过曲线拟合得到了倾角为0。、45。、90。结构面距隧洞1m时的尺寸效应公式。
[Abstract]:With the development of tunnel construction in our country towards the direction of "long, large, deep and group", the stability of the tunnel under the control of hard structure surface has been paid more and more attention.In this paper, the finite element software Midas/GTS is used to simplify the excavation of deep buried hard rock tunnel under the control of structural plane as a plane strain problem, which affects the stability of deep buried hard rock tunnel on its own characteristics and different lithologic conditions.In this paper, the effects of different ground stresses on the stability of deep buried hard tunnel and the size effect of structural plane under gravity stress are simulated.The effect of hard structure on the deformation of surrounding rock and plastic zone of tunnel under different conditions is analyzed quantitatively, which has some reference value for the practice of relevant engineers.Taking the deformation of surrounding rock as the main index, the maximum influence distance and effective influence distance of hard structure facing deep hard rock tunnel are determined.And the influence on the deformation of tunnel surrounding rock when the characteristic of structure plane changes.) the influence of structure on tunnel stability when lithology changes is analyzed, which shows that good lithology is helpful to reduce the adverse effect of structural plane.The bad lithology will enhance the adverse effect of the structural plane, and the lithologic parameters are analyzed separately, and it is found that the tensile strength of rock mass has no effect on it, while the elastic modulus, the angle of internal friction,The effect of cohesive force on the structure plane is analyzed in different high ground stress forms. It is shown that the structure plane is affected by the lateral pressure coefficient or the self-gravity stress when the lateral pressure coefficient is increased or the weight stress is increased.The most unfavorable distribution of the small structural plane at certain inclination angle and distance is determined, the concept of maximum effective influence size is put forward, and the size effect of the structural plane under the condition of high ground stress hard rock is analyzed.The relationship between the maximum effective influence dimension and the angle of inclination and distance within the effective influence distance of the structure plane is obtained, and the inclination angle is 0.45.90 by curve fitting.The size effect formula of the tunnel with a distance of 1 m from the structure surface.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455

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