【作者】 刘秀军；

【导师】 贺建清； 徐望国；

【作者基本信息】 湖南科技大学 ， 土木工程， 2011， 硕士

【摘要】 在山区修建高等级公路,不可避免地会遇到大量高填方路堤、斜坡地基路堤,有时也会遇到软土地基路堤。上述三种工况中,任何一种工况下的路堤都是极易发生破坏的,如果这三种工况集于一身,那么路堤破坏的可能性就不言而喻,因而及时精确地对路堤的破坏型式及其稳定性进行分析,进而采取相应的支护手段也变得尤为重要。本文以郴宁高速公路K183+440^K183+680段软基斜坡高填方路堤为依托工程,在收集前人研究资料和现场实地勘察、监测的基础上,对软基地段斜坡高填路堤破坏型式进行了分析。通过理论分析和数值模拟相结合的方法,对软基地段斜坡高填路堤稳定性进行了研究。本文所作的主要工作如下:（1）基于现有极限平衡法,利用经典土压力理论设定合理土条推力线范围,根据静力平衡及力矩平衡条件建立以条块界面安全系数F_v为变量的线性超定方程组。依据极大值原理及条块界面安全系数不小于条块安全系数的合理性条件:F_v≥F_s,推导出了基于最小二乘原理的边坡稳定性分析方法。（2）基于现有极限分析上限法,构建了边坡圆弧滑动径向条分破坏模式,解决了协调速度场难以建立的问题。采用塑性力学极限分析原理,结合强度储备安全系数定义法,推导出了均质土坡稳定性径向条分极限上限法。（3）依据监测数据及路堤断面设计型式分析了路堤破坏型式,在此基础上使用各种传统稳定性分析方法及本文改进法,对路堤各典型断面的稳定性进行分析。（4）根据依托工程地形地貌条件、地质结构特征,应用地质目标计算机辅助设计软件（GOCAD）建立了依托工程的三维地质模型,并采用FLAC^3D软件模拟分析了依托工程路堤分层填筑过程中在自重作用下的变形规律及稳定性。更多还原

【Abstract】 A large number of high filled embankments or embankments on slope ground, sometimes embankments on soft-soil ground, will be inevitably encountered in highway construction in mountainous areas. Every type of the embankment mentioned above is liable to lose its stability. If an embankment is constructed in situation in which the previous three conditions are all satisfied, the probability of its failure will be evidently increased. Therefore, it is very important to study the failure patterns and stability of this embankment timely and accurately in order to adopt corresponding support measures.In this paper, depending on the project of high filled embankment on slope and soft-soil foundation in the Chen-Ning highway from K183+440 to K183+680, the destruction pattern was analyzed on the basis of collecting previous researches, investigating and monitoring in the field. Combining theoretical analysis with numerical simulation, the stability of this embankment was also studied. Main achievements are concluded as follows:（1）After reviewing recent limit equilibrium methods, the classical earth pressure theory was utilized for setting the reasonable thrust line position of soil slice. The over determined linear equations including F_v as variable were established by the condition of static equilibrium and torque equilibrium, where F_v is the safety factor of the slice interface. According to maximum principle and the reasonable conditions: F_v≥F_s, a method of slope stability analysis which is based on the least squares theory was proposed in this paper.（2）After reviewing recent limit analysis law, a circular sliding failure mode of slope employing radial slice method was built to slove the key problem that the coordination velocity field is difficult to establish. Based on the limit analysis theory of plasticity, the upper limit method of radial slice analysis of homogeneous slope was derived according to the definition of strength safety coefficient in this paper. （3）According to monitoring data and the designed section type, the failure pattern of this high filled embankment on slope and soft-soil foundation was analyzed. And then, the safety factors of each typical section were analyzed by employing the traditional analysis methods and the modified methods proposed in this paper.（4）According to the terrain conditions and geological structure features of this high filled embankment on slope and soft-soil foundation, a three-dimensional geological model was set up by the geological object computer aided design software （GOCAD）. FLAC^3D program was used to analyze the deformation and stability of this embankment under its self-weight when layer by layer filled.更多还原