【作者】 姚元锋；

【导师】 赵晓彦；

【作者基本信息】 西南交通大学 ， 地质工程， 2010， 硕士

【摘要】 全风化花岗岩边坡在我国南方分布较广,这种边坡“保留或部分继承了原岩的结构面等其它岩体特征且未经二次堆积,稳定特性明显区别于均质土边坡及岩质边坡”,边坡介质多具有较高的摩擦角,在抗滑桩支挡下会形成较明显的土拱效应。本文通过模型试验、数值模拟及理论分析方法研究该类边坡的土拱效应及其主要影响因素,得出了如下研究成果：(1)通过现场调研,将全风化花岗岩边坡按边坡的结构组合特征分成四种类型,总结了该类边坡破坏方式的几种不同方式。(2)提出研究土拱效应的常规物理模型试验方法并研制了试验仪器。通过模型试验研究和数值模拟相结合,得出了全风化花岗岩边坡的土拱效应特征及其影响因素。分析了土拱高度与桩间净距、桩宽、土体性质间的关系,认为土拱高度主要与桩间净距和土体内摩擦角有关；桩宽决定了拱体厚度,影响土拱拱体的强度,从而影响土拱效应；粘聚力对土拱高度影响不大,但影响土拱拱体强度,从而影响土拱效应的强弱。(3)引入勃郎特-维西克(Prandtl-Vesic)地基承载力理论,提出了土拱的形状及土拱高度计算方法。土拱形状可认为是等腰三角形,得出其函数方程,在此基础上进行了全风化花岗岩边坡桩间土拱高度的计算,经与模型试验得出的拱高相比,证明该计算方法是可行的。(4)依据试验结果指导全风化花岗岩边坡的桩与桩间结构物设计更多还原

【Abstract】 Completely weathered granite residual soil slope has a wide distribution in the south of China.This slope retains or partly inherits other rock features,eg structural plane of the original rock,etc and without a secondary deposit, and also has stability characteristics that is significantly different from the homogeneous soil slope and rock slope. And has a high friction angle, the structural engineering Supporting and Retaining in the anti-slide piles will form soil arching effects.This paper use model test, numerical simulation and theoretical analysis for study of soil arching effect of this slope and its main affecting factors research, results obtained are as followings:(1) Based on-site survey,the completely decomposed granite residual soil slope can be divided into four types according to the slope structure assemblage characteristics, and summed up several different failure mode of this soil cutting slope type.(2) Conventional physical model test method is proposed for soil arching effect study, and test instrument is developed. According to model experiments combined with numerical simulation study, the characteristics of completely decomposed granite residual soil slope arching effect and its impact factors is presented.Also the relationship between the soil arch height and pile spacing,pile width,soil properties is analyzed. The results indicated that soil arching height is maily affected by pile spacing and soil friction angle.while pile width determines the arch thickness which affecting the strength of soil-arch-arch body, thus affecting the strength of soil arching effect. Soil arching height is little affected by cohesion of the soil, but the soil-arch-arch body strength can be affected thus affecting the strength of soil arching effect.(3) Based on the Bo Prandtl-Vesic foundation bearing capacity theory,the calculation method of soil arching shape and arching height is proposed.lt is confirmed that soil arch can be considered as an isosceles triangle shape, and its functional equation is presented. The height of soil arching in Completely weathered granite residual soil slope is calculated with this theory.Compared with the model test result, it is concluded that this method is feasible.(4) Based on the experimental result,it can give euidance to the design of pile and structure between pile on the completely weathered granite slope.更多还原