文家坪边坡稳定性评价及防治措施研究

发布时间：2018-05-13 01:34

本文选题：滑坡 + 稳定性分析　；参考：《中国矿业大学》2015年硕士论文

【摘要】：滑坡是自然界中常见的地质灾害,分布广泛、发生频繁、危害性大。一旦失稳滑动,将严重威胁人民群众的生命财产和各种工程安全,造成重大损失。随着人类工程活动规模日益扩大,矿山开采、交通运输、水利等建设工程中所遇到的滑坡稳定性问题也越来越突出。因此通过实地考查分析滑坡成因机制,利用科学手段评价滑坡稳定性,采取相应措施对危险滑坡进行治理,对于滑坡地质灾害的防治,保障人民生命财产的安全具有最要意义。本文以四川省达州市文家坪滑坡为研究对象,在收集各种相关地质资料的基础上,结合地质工程评价原理、土力学、工程地质学、水文地质学等理论对滑坡区的自然地理条件、水文地质条件、工程地质条件进行了分析,了解滑坡的基本特征、形成机理和发展变化规律。然后采用工程地质分析法和极限平衡法对滑坡进行定性和定量评价。建立地质力学模型,利用数值分析方法对边坡稳定性情况进行分析。而后根据评价的结果,选取合适的相似材料建立物理模型,进行滑坡模型试验,观察降雨工况下边坡变形情况。主要得出以下结论:(1)根据现场踏勘可知,滑坡体变形主要集中在C区和D区后缘及中上部,多以拉裂缝为主。后期降雨使斜坡变形逐步发展,目前尚未形成贯通性滑动带。(2)根据已有资料对滑坡稳定性进行了定性和定量分析与评价,计算出暴雨工况下安全系数小于1.05,表明该滑坡在天然工况下稳定,在暴雨工况下欠稳定。(3)运用有限元分析软件ABAQUS,通过构建地质模型,运用强度折减法进行数值模拟分析,分析其塑形变形特征和变化规律,所得结果与实际工程相符。(4)模型试验结果表明该滑坡发展过程是一个循序渐进的过程,其主要划分为五个阶段:即坡体渗流路径和坡面冲蚀沟的形成阶段、变形阶段、滑动阶段、剧滑阶段及稳定阶段。(5)降雨过程中裂缝发展对边坡稳定性有着重要的影响,其主要表现为:裂缝中由于持续降雨形成积水,产生静水压力,增加了坡体下滑力,减弱滑面阻力,滑面处抗滑力减小,抗剪强度降低,进而稳定系数降低,促进滑坡发生。(6)根据文章稳定性分析及下滑推力的计算的结果,推荐治理方案采用“抗滑桩分级支挡工程+裂缝封填工程”的综合治理方案。
[Abstract]:Landslide is a common geological hazard in nature, which is widely distributed, frequent and harmful. Once unstable and sliding, it will seriously threaten the life and property of the people and the safety of all kinds of projects, causing great losses. With the increasing scale of human engineering activities, the landslide stability problems encountered in mining, transportation, water conservancy and other construction projects are becoming more and more prominent. Therefore, it is of the most important significance for the prevention and control of landslide geological hazard and the safety of people's life and property to analyze and analyze the formation mechanism of landslide on the spot, to evaluate landslide stability by scientific means, and to take corresponding measures to control dangerous landslide. This paper takes Wenjiaping landslide in Dazhou City, Sichuan Province as the research object. On the basis of collecting all kinds of relevant geological data, combined with the theory of geological engineering evaluation, soil mechanics, engineering geology, hydrogeology and so on, this paper analyzes the natural geographical conditions of the landslide area. The hydrogeological conditions and engineering geological conditions are analyzed to understand the basic characteristics, formation mechanism and development law of landslide. Then the engineering geological analysis method and limit equilibrium method are used to evaluate the landslide qualitatively and quantitatively. The geomechanical model is established and the stability of slope is analyzed by numerical analysis method. Then according to the evaluation results, the physical model is established by selecting suitable similar materials, and the landslide model test is carried out to observe the slope deformation under rainfall conditions. The main conclusions are as follows: (1) according to the field survey, the deformation of the landslide is mainly concentrated in the rear edge and upper part of area C and D, and is mainly composed of tensile fractures. The slope deformation is gradually developed by rainfall in the later period, but no through slip zone has been formed at present. (2) according to the available data, the stability of landslide is qualitatively and quantitatively analyzed and evaluated. The safety factor is less than 1.05 under heavy rain condition, which indicates that the landslide is stable under natural condition and unstable under rainstorm condition. (3) by using finite element analysis software Abaqus, the geological model is built and the strength reduction method is used to carry out numerical simulation analysis. The results of model test show that the development of the landslide is a step by step process. It is mainly divided into five stages: the formation stage of slope seepage path and erosion trench on slope surface, deformation stage, sliding stage, sharp sliding stage and stabilization stage) the development of cracks has an important influence on slope stability during rainfall. The main results are as follows: hydrostatic pressure is produced due to the continuous rainfall in the cracks, which increases the sliding force of the slope body, weakens the sliding surface resistance, reduces the anti-slip force and reduces the shear strength at the sliding surface, and then the stability coefficient decreases. According to the analysis of the stability of the paper and the result of the calculation of the sliding thrust, it is recommended that the comprehensive treatment scheme of the crack sealing project of the anti-slide pile grade supporting and retaining engineering should be adopted.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

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