降雨对矿区膨胀性软岩边坡的稳定性影响分析

发布时间：2018-04-28 19:12

本文选题：露天煤矿 + 边坡稳定性　；参考：《昆明理工大学》2015年硕士论文

【摘要】：露天煤矿生产过程中边坡的稳定和安全直接关系到矿山企业生命和财产安全,是保证矿山正常生产的先决条件。边坡失稳的原因是多方面的,水是诱发滑坡破坏最主要的外因。本文以某露天矿大量工程地质勘察资料和边坡岩体特性分析为基础,进行了北帮高边坡滑坡破坏机理研究,并运用饱和-非饱和渗流理论和降雨入渗理论,通过SEEP/W数值模拟软件对膨胀性软岩边坡在降雨入渗条件下渗流场分析,然后将计算出来的瞬态渗流场结果与极限平衡法相结合,对边坡稳定性进行分析研究,探讨了不同因素对稳定性的影响。最后针对北帮边坡滑移变形特点简要提出边坡治理措施。本文主要从以下几个方面开展研究。1、以达西定律为基础,分析饱和—非饱和渗流微分方程以及饱和—非饱和渗流方程计算定解条件,以此作为后续有限元降雨入渗数值模拟的计算基础。2、通过分析露天煤矿所处工程地质条件、水文地质条件、结合岩样的室内力学试验和野外现场试验的成果,探讨边坡变形特征和破坏机理。揭示北帮膨胀性软岩边坡的变形破坏遵循“胀缩开裂—浸水软化—滑移”的循环规律。3、用有限元数值模拟软件,在渗流分析中考虑裂隙和不考虑裂隙两种情况下降雨渗流场对比分析,结果表明不考虑膨胀性软岩裂隙影响,大雨3天后,降雨作用下,孔隙水压力在2米以下基本不受影响,由此可见北帮膨胀性软岩边坡降雨渗流分析考虑裂隙存在对于边坡稳定的影响更为合理。4、利用SEEP/W有限元分析软件对边坡进行渗流场分析,并把分析结果与极限平衡法结合,研究了降雨强度、降雨历时和渗透系数大小对于膨胀性软岩边坡稳定性影响的程度,得出了降雨强度、降雨历时及渗透系数大小对边坡安全系数的影响规律。
[Abstract]:The stability and safety of slope in opencast coal mine production process is directly related to the safety of life and property of mining enterprises and is the prerequisite to ensure the normal production of mines. There are many reasons for slope instability, and water is the main external cause of landslide failure. Based on a large amount of engineering geological survey data and analysis of slope rock mass characteristics of a certain opencast mine, the failure mechanism of high slope landslide in the north slope is studied in this paper, and the theory of saturated-unsaturated seepage flow and rainfall infiltration theory are used. The seepage field of expansive soft rock slope under the condition of rainfall infiltration is analyzed by SEEP/W numerical simulation software, and the stability of the slope is analyzed by combining the calculated transient seepage field results with the limit equilibrium method. The influence of different factors on stability is discussed. Finally, according to the slip deformation characteristics of north slope, the slope treatment measures are put forward briefly. Based on Darcy's law, the differential equation of saturated-unsaturated seepage and the conditions for calculating the definite solution of saturated-unsaturated seepage equation are analyzed in this paper. This is the basis of numerical simulation of rainfall infiltration by finite element method. By analyzing the engineering geological conditions and hydrogeological conditions of open pit coal mines, combined with the results of indoor mechanical tests and field tests of rock samples, The deformation characteristics and failure mechanism of slope are discussed. It is revealed that the deformation and failure of the expansive soft rock slope of the north slope follow the cyclic law of "dilatation and shrinkage cracking, water immersion softening and slip", and the finite element numerical simulation software is used to simulate the deformation and failure of the slope. The comparative analysis of rainfall seepage field under the condition of fissure and no consideration of fissure in seepage analysis shows that the influence of expansive soft rock fissure is not considered. After 3 days of heavy rain, the pore water pressure under rainfall is basically unaffected. Therefore, it is more reasonable to consider the influence of cracks on slope stability by rainfall seepage analysis of expansive soft rock slope of north slope. The seepage field of slope is analyzed by SEEP/W finite element analysis software, and the analysis results are combined with limit equilibrium method. The influence of rainfall intensity, rainfall duration and permeability coefficient on the stability of expansive soft rock slope is studied, and the influence law of rainfall intensity, rainfall duration and permeability coefficient on slope safety factor is obtained.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD824.7

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