层状反倾向岩质边坡破坏机理研究

发布时间：2018-03-13 07:43

本文选题：层状　切入点：反倾边坡　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：层状边坡在岩质边坡中较为常见,其主要岩石类型为沉积岩和变质岩。层状边坡包括顺倾向和反倾向边坡,传统观念认为反倾向边坡较稳定,然而秦巴山区出露岩层以古生界变质岩为主,在安康—神河一带,山体出露岩层主要为石英片岩、钙质板岩、砂质千枚岩等,其岩体强度低、结构破碎,从而该地区反倾向边坡破坏时有发生。目前,此类边坡的破坏模式、破坏机理的研究相对薄弱。工程实践表明,反倾向边坡一旦发生失稳破坏,将产生严重的工程灾害。一般将层状反倾向岩质边坡的破坏类型分为滑移和倾倒两种基本模式,而根据现场调查及地质勘查等手段,大多数反倾向岩质边坡的破坏模式无法判别为滑移或倾倒,且边坡破坏形式复杂多变。因此,本文针对层状反倾向边坡失稳问题开展研究,采用数值模拟和理论分析相结合的手段,分析其破坏模式,论证其破坏机理。本文采用基于岩体强度折减有限元模型,该模型考虑了岩石与结构面属性,也考虑了剪应力屈服与拉应力屈服;有限元计算以Phase2有限元软件为平台,以典型千枚岩反倾向边坡为研究对象;对岩体进行了理想化假设,即认为边坡岩体由层状岩石和结构面组成,岩体被结构面均等分割,岩石是各向同性的均质连续理想弹塑性体;模拟边坡坡角、岩层倾角、边坡高度等要素变化时反倾向边坡破坏特征。通过研究建立了张拉破坏与弯拉破坏的判别标准及滑移破坏与倾倒破坏模式的判别标准。将层状反倾向岩质边坡破坏模式总结为五种类型:滑移、面滑内倾(坡面滑移——坡内倾倒)、下滑上倾(下部滑移——上部倾倒)、倾倒、内滑外倾(坡内滑移——坡外倾倒),并根据破坏模式总结了防治指导建议。
[Abstract]:Layered slope is common in rock slope, and its main rock types are sedimentary rock and metamorphic rock. However, the exposed strata in Qinba Mountain area are mainly Paleozoic metamorphic rocks. In the area of Ankang-Shenhe, the exposed rocks of the mountain body are mainly quartz schist, calcareous slate, sand phyllite and so on. Their rock mass is low in strength and broken in structure. At present, the research on the failure mode and mechanism of this kind of slope is relatively weak. Serious engineering disasters will occur. Generally, the failure types of layered anti-inclined rock slopes can be divided into two basic modes: slip and toppling, and according to the methods of field investigation and geological exploration, Most of the failure modes of anti-inclined rock slopes can not be distinguished as sliding or toppling, and the failure forms of slopes are complex and changeable. Therefore, the instability of layered anti-inclined slopes is studied in this paper. In this paper, a finite element model based on strength reduction of rock mass is used to analyze its failure mode and demonstrate its failure mechanism by means of numerical simulation and theoretical analysis, which takes into account the properties of rock and structural plane. The shear stress yield and tensile stress yield are also considered, the finite element calculation is based on Phase2 finite element software, and the typical phyllite slope is taken as the research object. That is, the slope rock mass is composed of layered rock and structural plane, the rock mass is divided equally by the structural plane, the rock is isotropic and homogeneous continuous and ideal elastoplastic body, the slope angle of the slope is simulated, the slope angle, the slope angle, the slope angle, the slope angle, the slope angle, In this paper, the criterion of tensile failure and flexural failure and the criterion of slip failure and toppling failure mode are established by studying the characteristics of slope failure when slope height and other factors change. The layered reverse inclined rock slope is broken. Bad patterns are summed up in five types: slip, The slope slip (slope slip -slope topping), the downward dip (lower slip-upper toppling, the toppling, the inner slip outside the slope) and the prevention and cure suggestions are summarized according to the failure mode.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45

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