含软弱夹层红砂岩边坡水毁机理及加固研究

发布时间：2018-03-03 01:22

本文选题：边坡稳定性　切入点：红砂岩　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,我国红砂岩分布地区高速公路常出现边坡滑坡事故,绝大部分缘于持续降雨和软弱夹层等原因。本文大量收集学习了国内外边坡渗流和稳定性的科研资料,以杭瑞高速公路常吉段K1193滑坡为工程背景,通过考虑渗流规律提出了一种改进的机动位移法,以此来评价含软弱夹层红砂岩边坡的稳定性。并设计了一组正交试验来探讨该类型边坡的滑坡机理以及软弱夹层各项因素对边坡稳定性的影响。最后基于理论研究和试验结果提出了一种针对该类型边坡的排水治理方法。主要工作内容有： (1)研究了软弱夹层的渗流规律,认为软弱夹层中孔隙水压力在水压水头大于软弱夹层厚度时呈直线规律减小,在小于软弱夹层厚度时呈二次型减小。基于此规律改进了机动位移法,推导出考虑软弱夹层渗流规律的边坡稳定性判据。 (2)根据相似原理和正交试验原理,开展了一组含软弱夹层红砂岩的边坡模型试验。试验以软弱夹层埋深,倾角,粘聚力和初始含水量为自变量,研究了软弱夹层渗流场和边坡稳定性的变化规律。研究表明,软弱夹层渗流场受埋深和倾角影响较大；边坡稳定性与软弱夹层埋深和粘聚力成正比,与其倾角成反比,当初始含水量为软弱夹层的最佳含水量时,边坡稳定性最高。 (3)试验所得的破坏荷载可等效为一定深度的后缘裂隙水深(破坏值),实际边坡稳定性可通过比较具体工况下的裂隙水深与破坏之进行判别。该判断结果与本文所提出的边坡稳定性判据理论值基本一致。说明该理论判据能用于含软弱夹层红砂岩边坡稳定性评判。 (4)从排水的角度出发,提出了分区截水集中排水的排水治理方法,进行了排水加固试验。运用理论推导的边坡稳定性判据分析了排水治理前后的边坡稳定性,能量系数由0.94提高到1.19,说明该方法有较好的治理效果。
[Abstract]:In recent years, slope landslide accidents often occur on highways in red sandstone distribution areas in China, mostly due to continuous rainfall and weak intercalation. This paper collects and studies the scientific research data of slope seepage and stability at home and abroad. Taking the K1193 landslide in Changji section of Hangzhou and Rui Expressway as the engineering background, an improved mobile displacement method is proposed by considering the seepage law. In order to evaluate the stability of red sandstone slope with weak intercalation, a group of orthogonal tests are designed to study the landslide mechanism of this type of slope and the influence of various factors of weak intercalation on slope stability. A drainage treatment method for this type of slope is proposed based on the investigation and test results. The main contents of the work are as follows:. 1) the percolation law of weak intercalation is studied. It is considered that the pore water pressure in weak intercalation decreases linearly when the water pressure head is larger than the thickness of weak intercalation. On the basis of this law, the dynamic displacement method is improved, and the slope stability criterion considering the seepage law of weak intercalation is derived. (2) according to the principle of similarity and orthogonal test, a group of slope model tests of red sandstone with weak intercalation are carried out. The independent variables are buried depth, inclination angle, cohesion and initial water content of soft intercalation. The variation law of seepage field and slope stability of weak intercalation is studied. The results show that the seepage field of weak intercalation is greatly affected by buried depth and inclination angle, and the slope stability is directly proportional to the buried depth and cohesive force of weak intercalation, and is inversely proportional to its dip angle. When the initial moisture content is the optimum moisture content of the weak intercalation, the slope stability is the highest. 3) the failure load obtained from the test can be equivalent to a certain depth of the depth of the fissure water depth (failure value). The stability of the actual slope can be judged by comparing the crack water depth with the failure under the specific working conditions. The result is in agreement with that of the present paper. The theoretical values of the proposed slope stability criterion are basically consistent, which shows that the theoretical criterion can be used to evaluate the stability of the red sandstone slope with weak intercalation. 4) from the point of view of drainage, this paper puts forward the drainage treatment method of district water interception and centralized drainage, and carries out drainage reinforcement test. The slope stability before and after drainage treatment is analyzed by using the slope stability criterion derived from theory. The energy coefficient is increased from 0.94 to 1.19, which shows that this method has better control effect.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U418.54

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