【作者】 王建强；

【导师】 陈庆寿；

【作者基本信息】 中国地质大学（北京） ， 岩土工程， 2010， 博士

【摘要】 边坡问题是与地震及火山并列的危害人类生命财产安全的三大地质灾害之一。边坡稳定性研究发展到今天,经历了一个逐步由定性向半定量、定量、不确定分析方法逐步发展完善和丰富的过程。由于边坡发生的地质条件复杂、作用因素众多且具有不确定性,边(滑)坡的发生机理还不能完全掌握,任何一种边坡稳定性评价方法都很难全面、准确、客观的评价坡体的变形演化过程,所以边(滑)坡的稳定性研究仍需不断的探索和总结。本文将以保腾高速公路龙江特大桥桥基区高边坡为研究背景,以边坡的地质结构条件、岩土体物理力学参数和边坡形成演化资料为基础,首先,利用颗粒流方法,模拟了岩质和土质边坡的形成演化机理,分析了各种影响因素在边坡稳定性中的作用,深化了对边坡的破坏机理和影响因素的认识;其次,在充分收集和整理了目前国内外边坡稳定性评价方法的基础上,对同一复杂高边坡,采用定性分析方法、极限平衡法(GLE通用条分法)、有限差分强度折减法和历史地形演化评价法等多种稳定性评价方法,从不同的角度综合评价边坡稳定性,并分析总结了各种评价方法的适应性。颗粒流方法研究表明:对于岩质边坡而言粘聚力对边坡稳定性的影响大于内摩擦角,岩质边坡的破坏往往是受临空面、结构面和软弱层组合控制,同时卸荷裂隙和节理对破坏模式也起到一定控制作用;松散层边坡的破坏与其颗粒形态、粒径大小有密切联系,颗粒组越大则整体稳定相对提高,局部稳定变差,颗粒越小、级配连续,则局部稳定好,整体稳定性受物理力学性质控制。对边坡的不同评价区域,进行了三维FLAC拉格朗日有限差分计算与二维极限平衡数值计算。三维FLAC拉格朗日有限差分计算,可以得到评价区域的滑体范围与相应的安全系数,滑体范围可以展现滑体在空间的分布与尺寸,滑体的主滑方向。二维极限平衡分析可以搜索得到多个滑面及其相应的安全系数,可以对不同部位的滑坡体进行最危险滑面的搜索,也可以指定滑动面计算相应的安全系数。三维拉格朗日有限差分计算安全系数与二维极限平衡计算得到的安全系数变化规律相似,坡体各部位三维计算的整体安全系数要比二维计算结果偏大;历史地形演化法评价的边坡稳定区块与其它评价方法结论一致。本文以定性分析为基础,利用三维FLAC拉格朗日有限差分法和二维极限平衡法计算结果,结合历史地形演化的稳定性分析方法,综合得到边坡的安全系数和相关极限状态下的滑体范围,多种评价方法综合客观的反映了边坡稳定性现状,为边坡加固和处理提供了科学合理的依据。希望本文的工作,对于深入、科学的认识该区边坡有所裨益,也希望本文的边坡稳定性研究方法能为类似复杂高边坡的研究有借鉴意义。更多还原

【Abstract】 Slopes, earthquake and volcano are three major geological disasters, which do great harm to people’s lives, property and safety. To this day, the studies of the stability have experienced a period of from qualitative analysis, half-quantitative analysis, quantitative analysis to uncertain analysis. Because of the complexities of geological condition, and other uncertain influence factors, it is difficult for us to grasp the theory of slopes completely. No method can valuate the slope’s deformation procedure completely, accurately and objectively, so the slope stability still need deep exploration and .studies.In this essay, the research background is set in the high slopes of Long Jiang grand bridge foundation area which is on the Baoshan-Tengchong Highway, and it is based on the slope geological structure condition, the physical and mechanical parameters of rock and soil and the formation and evolution of the slope. First, the method of particle flow, are used to simulate the evolution mechanism of rock and soil slope and to analyze different kinds of influence factors in the slope stability. According to these analysis, the slope damage mechanism are disclosed. Second, by virtue of sufficient collection of domestic and foreign assess methods of slope stability. different kinds of stability methods of qualitative analysis, such as limit equilibrium(GLE general slice method), finite element strength reduction and historical topography and so on, are used to analyze a certain complex high slope, and to evaluate slope stability from different points of view and to analyze different compatibilities of those mehtods.The research by particle flow method shows: for rock slopes, the influence of cohesion on slope stability is more severe than that of internal friction angle. The stability of rock slope is controlled by the combination of free faces, structural planes and soft layers, so are the unloading fractures and joints; the damage of loose rock slope has close connection with its particle shape and size, the bigger of the particle group, the higher of the whole stability, the less of the part stability; if the particles are smaller and its gradation is continuous, the local stability will be greater, and the whole stability will be controlled by rock and soil physical and mechanical properties.For stability evaluations of different slope areas, ,the methods of 3D FLAC Lagrangian finite difference and Two-dimensional limit equilibrium are used. By 3D FLAC Lagrangian finite difference, the range of landslide and corresponding safety factor can be acquired. The landslide range can show the landslide’s space distribution ,its size and its main sliding direction. The method of 2D limit equilibrium can be used on several sliding surfaces for finding out the corresponding safety factors, and this method can be used for acquirement of the most dangerous slide surface by its application on the different parts of the landslide, and it also can be used for a specified sliding surface. The differences of safety factor between the two methods are similar, but the safety factor by Lagrangian finite difference is larger than that of Two-dimensional limit equilibrium. The result from historical topographic evolution method is consistent with other evaluation methods.In this essay, on the basis of three qualitative analysis methods, which are Three-dimensional Lagrangian finite difference, Two-dimensional limit equilibrium, and the stability method of historical topographic evolution, the slope’s safety factor and the landslide range can be acquired. Diversified evaluation methods can show the present situation of the slope stability objectively , and they provides the scientific basis for the slope reinforcement.It is hoped that the essay is helpful to the study on the slopes, and the methods in the essay could be a good reference to the complex high slopes similar to Long Jiang bridge..更多还原