【作者】 邓俊晔；

【导师】 徐卫亚；

【作者基本信息】 河海大学 ， 防灾减灾工程及防护工程， 2006， 硕士

【摘要】 工程中的有限元计算能反映边坡的变形特征、应力状态和破坏机理,但是尚不能给出一个直观的安全系数。刚体极限平衡分析方法,虽然能够得到直观的安全系数和危险滑弧位置,但是在破坏机理研究上有一定的局限。迫切需要发展一种将有限元计算结果同极限平衡分析方法相结合的极限平衡有限元方法。本文基于这种思路,引入图论和网络模型的方法解决边坡滑弧的搜索问题,实现了危险滑弧的自动搜索,计算其最小安全系数。讨论了边坡安全系数在不同材料模型下的定义与具体计算的问题,得到安全系数的一个新的计算方法。应用这种搜索边坡滑动面的方法讨论了不同参数对边坡滑动面位置及安全系数的影响。最后将这种方法应用在白鹤滩与洛古水电站边坡工程。具体研究工作如下: (1)、采用数学上的图论的方法解决边坡极限平衡有限元问题。在对图论中的相关内容做了大量的研究后,认为图论中解决最短路问题的Dijkstra算法能应用于进行边坡极限平衡有限元分析; (2)、将边坡极限平衡有限元分析中的有限元计算得到的应力结果转化为图论语言,并针对以安全系数为目标函数的边坡极限平衡有限元滑弧优化,修改Dijkstra算法,并对修改后的Dijkstra算法优化得到的边坡极限平衡有限元滑弧及其安全系数的充分性作了严格的数学证明; (3)、引入相关的力学原理,对修改后的Dijkstra算法进行了优化,使得修改后的Dijkstra算法更符合边坡的力学原理,计算效率得到了提高,并编制了相应的计算程序及其前后处理程序; (4)、应用编制的Dijkstra极限平衡有限元分析程序,进行了边坡极限平衡有限元的算例分析,对参数做了敏感性分析。在证明了Dijkstra算法的正确性的同时,得到了安全系数和滑弧位置随内摩擦角、内凝聚力、泊松比、弹性模量的变化趋势(变化曲线); (5)、针对洛古水电站坝址坝肩边坡剖面进行了极限平衡有限元分析,讨论了Dijkstra算法在进行逆坡向滑弧搜索的可行性,得到逆坡向发展的滑弧,特别是断层控制。的逆坡向滑弧是以拉应力控制的,并对这类以拉应力控制的滑弧的搜索提出了相应的处理方法;更多还原

【Abstract】 The FEM computation of engineering can reflect the characteristic of deformation, stress state and destroy mechanism of slope, but can not get an intuitionistic safety factory. Method of rigid limit equilibrium analysis, has a certain extent of localization in the investigation of destroy mechanism, though it can get an intuitionistic safety factory and the position of dangerous slide surface. So their needs a limit equilibrium FEM method impendence which combine the FEM compute result with the limit equilibrium analysis method. Base on this idea, introduced method of graph theory and grid model to solve the problem of search for dangerous slide surface, come true the auto search of dangerous slide surface, compute of the minimum of safety factory. The problem of definition of slope safety factory in different material model and the computation have been discussed, and then get a new method of compute safety factory. Application this method of search slide surface of slope, the different slope parameters to effect of the position of dangerous slide surface and safety factory have been discussed. In the end, this method application in the Bai-he Tan and the Luo-gu hydro-power slope engineering. The embody investigation works as follows:(1) Use the Graph theory method in mathematics to solve the problem of limit equilibrium FEM computation of slope. After doing a lot of investigation work on the correlative content of graph theory, make sure that the Dijkstra algorithm which used in solves the shortest path problem of Graph theory can analysis the slope stability problem;(2) Convert the FEM computes result in slope stability FEM of limit equilibrium analysis to the language of Graph theory, and aim to the function of safety factory on the optimize of slope limit equilibrium FEM analysis, and revise of the Dijkstra algorithm, and then do sufficiency theory prove on the slide surface and safety factory of slope limit equilibrium FEM analysis which get by the revised Dijkstra algorithm;(3) Introduce some correlation mechanics common sense to optimize the Dijkstra algorithm, to make the revised Dijkstra algorithm more accord to the slope mechanics theory, and also to improve the compute efficiency. Then edit the compute program and the fore-and-aft disposal procedure;(4) Use the Dijkstra limit equilibrium FEM analysis procedure, author have do the FEM of limit equilibrium analysis of a simple example slope, to prove the correction of the Dijkstra algorithm and do the parameters sensitivity of the simple slope, and get the varied curves of the relationship of the safety factory and the slide surface to the inner friction angle, cohesion, poison ratio and elasticity modulus;(5) According to the Luogu hydro-power dam site slope, doing the FEM of limitequilibrium analysis, and discuss the feasible of Dijkstra algorithm to search of the converse slide surface, then get of the converse slide surface, especially to the converse slide surface which controlled by the tension stress. And give off the disposal method to search of the converse slide surface which controlled by the tension stress.(6) Application the Dijkstra FEM of limit equilibrium analysis soft, author finished the plane FEM of limit equilibrium analysis of the slope stability of infall high slope in Baihe-Tan. To compare with the limit equilibrium method, get the consistent result: the destroy models of high slope in Baihe-Tan are deep-seated destroy, the infall slope is satisfy to the demand of the stability criterion in nature status, but the safety degree is not too ample;the safety factory is increase after excavation, if consider the excavation effect on the material parameter, the safety factory has a little decrease, but the slope is also in steady status;更多还原