【作者】 熊凯；

【导师】 凌道盛； 陈云敏；

【作者基本信息】 浙江大学 ， 岩土工程， 2006， 硕士

【摘要】 边坡工程是工程中最常见的工程形式,边坡工程中遇到的滑坡问题是全球三大地质灾害之一,严重危害人类的生命财产安全。随着我国经济建设的高速发展,边坡失稳问题日益突出,对边坡稳定问题的研究具有重要意义。 本文首先对目前常用的边坡稳定安全系数的分析方法:极限平衡法、有限元强度折减法、极限分析方法进行了简单的归纳和总结,详细分析了分别基于纯转动(Chen,1975)和纯平动(Michalowski,1995)运动场的边坡稳定安全系数的塑性极限分析上限解法。在此基础上提出了满足塑性流动法则,平动加转动的运动场及相应的边坡稳定安全系数计算方法。纯平动和纯转动运动场是本文提出的运动模式的二个特例。 本文分别假设滑动面为圆弧、对数螺旋线和任意形状滑动面,采用改进的蒙特卡洛法(李育超等,2005)搜索最危险的滑动面,并编制了相应的分析程序。通过大量的数值分析得到如下结论:(1) 对于给定的滑动面,转动速度分量对条间能量耗散有很大的影响,不同的转动速度对应不同的安全系数,最可能的转动速度使得该滑动面对应的稳定安全系数最小。(2) 与纯平动运动场相比,对于给定滑动面,本文提出的平动加转动的运动场能给出更小、更接近真值的安全系数上限解,两者的相对差别甚至可以高达20%。(3) 对于均质边坡,最危险的滑动面并非总是如Chen提出的对数螺旋线,特别是当土体的粘聚力较小时。(4) 基于相关联流动法则,采用土体内摩擦角计算出的安全系数比基于非相关联流动法则,采用剪胀角计算出的安全系数要偏大。 最后,本文对七子山垃圾填埋场扩建工程进行了稳定分析,指出当垃圾填埋体沿基底或者衬垫滑动时主要是发生平动破坏。更多还原

【Abstract】 Slope is one of the most familiar engineering. The slide slope is one of the three geologic disasters which may cause much property loss and also many deaths. As the fast development of the economy construction, the study on the stability of slope is of great significance.Firstly, this thesis introduces the most popular methods of the stability analysis of slope, including the Limit equilibrium approach, the finite element approach and limit analysis approach. Based on the rotation kinematical field and translation kinematical field, a particular study on the upper bound limit analysis of slope stability is made. A kinematical field considering both translation and rotation is proposed. And the rotation and translation kinematical field are just two particular examples of its.Assuming the critical slide surface are circle arc, logarithmic spiral and other arbitrary form, the thesis uses the improved Monte Carlo method to search the critical slide surface, and use the three kinematical approaches mentioned above to calculate the factor of safety. Based on a great number of numeric examples, the following conclusions can be made. (1) For a fixed slide surface, the angle velocity has great effect on the energy dissipation between the labor blocks. And the most possible angle velocity makes the minimum safety factor. (2)Comparing to the translation kinematical field, the approach proposed in the thesis can give a less value of safety factor which is more closed to the true value. (3)The critical surface is not always the one proposed by Chen for a homogeneous slope. (4)The safety factor is higher when non-associate flow rule is used. At last, the safety factor of a landfill is analysed.更多还原