【作者】 卢晓春；

【导师】 田斌；

【作者基本信息】 三峡大学 ， 水工结构工程， 2008， 硕士

【摘要】 随着我国国民经济的快速发展和国家对基础设施建设投入的不断加大,铁路、交通、能源、矿山、水利水电等工程领域不可避免的逐步形成了大量的岩质高边坡工程,这些边坡工程中一般都存在着岩体稳定性问题,有些问题已成为工程建设进度与安全的重要制约因素。自然状态下的岩体经过漫长的地质年代作用后,一般处于稳定的平衡状态。由于工程建设的需要,岩质边坡需要进行开挖、地应力释放、原有的应力平衡状态打破、边坡岩体应力场重分布。而这种应力场的重分布要靠边坡岩体自身来承担。对于开挖边坡而言,要分析其稳定性需选用与其吻合的力学参数和分析方法。本文的研究目的是解决有限元数值方法在分析岩质边坡稳定性中的几个非线性问题。其中关键问题包括:岩体松弛区划分及各松弛区参数的确定;开挖等效荷载的分析及讨论;开挖引起渗流场的变化及其力学效应等。本文以解决上述关键问题为主线,开展了以下工作:(1)基于AutoCAD的有限元前后处理开发的研究,主要包括使用超单元法自动剖分网格,并采用AD算法对划分后的网格结点编号进行优化等;(2)编制了可以考虑拉剪破坏和压剪破坏的平面非线性有限元程序,并对程序编制中存在的非线性问题进行了探讨,并给出了相应的解决办法;(3)基于岩体的声波测试、岩体力学实验及岩体质量评价等手段,对岩质边坡的松弛区范围和相应区域的力学参数的确定进行了研究;(4)讨论了开挖等效荷载产生的原因及计算方法;(5)讨论了开挖引起的渗流场的变化及其力学效应的研究,并给出了相应的解决办法。更多还原

【Abstract】 With the rapid development of national economy and increment of financial aids provided by government in infrastructural facilities construction, lots of high rock slope engineering problems are encountered inevitably in the fields such as railway , transportation, energy, mine, water conservancy and hydroelectric power engineering. The slope stability of rock mass has become an important and restrictive factor in construction process and security of engineering.Rock mass in nature generally is in a stable equilibrium state after suffering lengthy process of geological age. During engineering construction, the rock slope must be excavated, which releases of geological stress, and disrupts the stable equilibrium state, and makes the stress field of slope rock mass be redistributed. Such redistribution of stress field is assumed by slope rock mass itself; that is to say, slope is in an unloading mechanical state after excavation. For this type of slope rock mass excavated , corresponding mechanical model, model parameters and analysis procedure should be selected to analyze its stability.This paper aims at solving some nonlinear problems in analysis of rock slope stability by finite element method. Some key issues are researched, such as dividing the unloading zones of rock mass, the parameters of unloading fractured rock mass excavated, the computation of excavation load, and the stability of slope on the unsteady seepage owing to the excavation.The main research works of this paper are list as follows:(1) Preprocessing and post-processing of the Finite Element based on the AutoCAD are researched, an automatic mesh generation method (super-element method) and an algorithm for optimizing the node number are introduced;(2) A two dimensional nonlinear finite element program considering the compression-shear and tension-shear is written, some nonlinear questions of finite element method are listed and solved;(3) By means of acoustic wave test and in-situ deformation test of rock masses, the excavation-disturbed zone and the mechanical parameters for disturbed zone rock masses are studied;(4) This paper discusses the cause of excavation load, and gives the computation metod of excavation load; (5) The stability of slope on the unsteady seepage owing to the excavation is discussed, and then the solution is given.更多还原