【作者】 王睿；

【导师】 朱彦鹏；

【作者基本信息】 兰州理工大学 ， 结构工程， 2010， 硕士

【摘要】 支挡结构作为一种结构物,其类型各式各样,其适用条件取决于支挡位置的地形、工程地质条件、水文地质条件、建筑材料、支挡结构的用途、施工方法、技术经济条件和当地工程经验的积累等因素。重力式挡土墙支护在我国早已被广泛应用于边坡与基坑的支护中,并显示出了较大的优越性和适应性。然而目前在重力式挡土墙支护的动力设计分析中采用拟静力法,没有考虑土、挡土墙及动力荷载的物理力学指标的随机性,导致在工程中某些挡土墙结构按拟静力法估计的安全系数是足够的,而投入使用后却很快发生了破坏。如果将考虑参数随机性的动力可靠度分析方法引入挡土墙支护的设计分析中,则可以减少很多破坏的发生。对于将动力可靠度方法引入挡土墙支护的设计计算中,国内外部分学者已经做了一些工作,本文在前人工作的基础上又进行了以下几方面的研究：(1)分析了影响挡土墙支护结构动力可靠度的随机变量,认为土的内摩擦角、重度、粘聚力,挡土墙的弹性模量、泊松比等均是服从正态分布的随机变量；根据动力可靠度理论,对挡土墙的动力破坏建立功能函数,并利用结构可靠度分析一次二阶矩法中的验算点法计算出失效模式的可靠度指标。(2)由于挡土墙和土体结构在地震作用下的相互作用关系非常复杂,建立确定的功能函数十分困难,所以本文采用了广泛应用的响应面法建立挡墙土体结构的隐式功能函数,对功能函数进行显式拟合。(3)利用最小二乘法得出功能函数中的回归系数,进而得到结构的极限状态方程。(4)利用编程软件matlab进行动力可靠度的编程,最终通过迭代求出结构的可靠度指标。(5)通过具体工程实例,计算得出结构在地震作用下的动力可靠度指标,进而得到沿墙高各节点的动力可靠度变化规律,从而为工程设计提供了参考。更多还原

【Abstract】 The gravity retaining wall supporting has been widely used in slope and excavation support in our country, and the gravity retaining wall supporting shows a greater superiority and adaptability. However, the gravity retaining wall supporting use of dynamic design analysis method to be static, without consideration of soil, retaining walls and the dynamic load of physical and mechanical indexes of randomness,then that lead to some retaining wall estimate by pseudo-static method, the safety factor is adequate, but the gravity retaining wall was put into use and the damage occurred quickly. If you introduce the parameters of random dynamic reliability analysis method to the design of retaining walls supporting, you can reduce the occurrence of damage. A dynamic reliability method inducts into the retaining wall designing and calculation of supporting.At home and abroad, some scholars have been done some work, this article makes a study to base on the previous work,as follow:(1)This text analyze the impact of the dynamic reliability of retaining wall with random variables, that conside the soil angle of internal friction, heavy, cohesive force, the elastic modulus, Poisson’s ratio normally distributed fliers random variable; According to dynamic reliability theory, and establishment of a function function, and use design point method in the first order second moment theory to calculate the reliability index failure mode.(2) The retaining walls and soil structure interaction under earthquake relations are very complex,performance function was so difficult to established, so in this text, the widely used response surface method was used to establish the implicit performance function of the soil and retaining wall structure, then fit an explicit performance function.(3)Using the least square method to get the regression coefficients in the performance function, and then get the limit state equation of the structure.(4) Using the software matlab to programming, the structure reliability index was obtained through the iterative finally.(5)Through specific examples, calculated the structure under earthquake dynamic reliability index, and then get the reliability index evolution of all the nodes along the wall altitude variation, and provides a reference design for the project.更多还原