近源堆沉积土石体细观结构与抗剪强度指标关联分析

细观结构是认知土石体力学行为本质的关键科学问题。本文通过引入物理学和数学等方法，借助颗粒物质力学理论，从几何排列与接触力的空间分布来定量刻画水平固结与山前坡地堆积两种典型环境下土石体的细观结构特征，并建立其与抗剪强度指标的关联。研究表明，（1）两种环境的土石体在细观结构上存在较大差异。在几何排列上，水平固结环境下的土石体具有长程无序和短程有序的特点，坡地堆沉积环境下的土石体表现出了无序的无定形结构；在接触力与单位接触向量的空间分布上，两者较为相似，绝大多数接触力以小于均值接触力的形式存在，其概率密度曲线P（f）呈幂函数衰减；90%以上接触方位角集中在40°~160°和220°~340°范围内。（2）基于径向分布函数、接触力概率密度和单位接触向量分别定义细观结构的特征量K_a，K_s和K_o，发现三个特征量的增大对内摩擦角呈线性促进作用，对黏聚力呈非线性削弱作用。

Correlation analysis of mesostructure and shear strength parameters of proximal deposit soil-rock mixture

The mesostructure is the key scientific problem in the mechanical characteristics of the soil-rock mixture.In this paper,by introducing physics,mathematics and other methods,with the help of granular matter mechanics theory,the mesostructure characteristics of soil-rock mixture are quantitatively described from the geometric arrangement and the spatial distribution of contact force under two typical environments,and establish its association with shear strength parameters is established.The results show that (1) There are significant differences on the mesostructure of the soil-rock mixture under the two environments.In the geometric arrangement,the soil-rock mixture under horizontal consolidation environment has long-range disorderly,but short-range orderly characteristics.The soil soil-rock mixture under the slope deposition environment shows a disorderly amorphous structure.The two are similar on the spatial distribution of contact force and unit contact vector.The majority of contact forces are less than the mean contact force,the probability density curve P(f) is a decreasing the power function.More than 90% contact azimuth is concentrated in the range of 40°~160° and 220°~340°.(2) Based on the radial distribution function,the contact force probability density and the unit contact vector,the characteristic quantities K_a,K_s and K_o have been defined.The influence of K_a,K_s and K_o on the internal friction angle shows a positive linear correlation,and the cohesion shows a decreasing trend of parabola with the increase of K_a,K_s and K_o.