论文部分内容阅读
土石混合体具有强烈的非均质性、非均匀性、非连续性和环境依赖性,从土石混合体的非线性角度出发,采用分形几何理论对土石混合体的细观结构特性进行描述,明确土石混合体重塑样的备制工艺,重点探讨土石混合体单轴压缩条件下应力–应变特征以及与特征强度值之间的联系。得出以下几点结论:(1)含石量作为研究土石混合体力学特性的重要指标,与土石混合体的粒度分维数密切相关,二者满足幂函数关系;(2)根据试样的单轴压缩曲线结合数值计算结果,将土石混合体峰前应力–应变曲线分为接触压密阶段、弹性阶段、慢裂阶段、快裂阶段,峰后表现为应变软化特征;(3)随着试样含石量的增大,土石混合体的单轴抗压强度在含石量为50%时最大,轴向应变随含石量的增大而增加,土石混合体的径向变形更为敏感;(4)数值试验结合土石混合体的室内压缩试验,定义土石混合体土石结合裂缝开裂应力,并用LSR法计算开裂应力值,开裂应力、扩容应力和峰值应力呈线性函数关系。土石混合体具有细观结构的层次性和相似性,应用分形几何学的有关理论研究土石混合体的结构力学特征不失为一个好的思路,可以更好地了解土石混合体这类地质材料的细观结构和力学性质。
The rock-soil mixture has strong heterogeneity, inhomogeneity, discontinuity and environmental dependence. According to the nonlinearity of the rock-soil mixture, the fractal geometry theory is used to describe the microstructure characteristics of the rock-soil mixture. The preparation process of the soil-rock mixture remodeling sample focuses on the stress-strain characteristics and the relationship between the stress and strain and the characteristic intensity under the uniaxial compression of soil-rock mixture. The conclusions are as follows: (1) The stone content is an important index to study the mechanical properties of soil-rock mixture, which is closely related to the particle size fractal dimension of the soil-rock mixture. Both of them satisfy the power function relationship. (2) Uniaxial compression curve and numerical calculation results, the pre-peak stress-strain curve of rock-soil mixture is divided into contact compacting stage, elastic stage, slow cracking stage and rapid cracking stage, and the peak appears as strain softening characteristic; (3) The uniaxial compressive strength of rock-soil mixture is the largest when the content of rock is 50%, and the axial strain increases with the increase of rock content. The radial deformation of rock-soil mixture is more (4) Numerical test Combined with the indoor compression test of soil-rock mixture, the cracking stress of soil-rock mixture combined with soil-rock mixture is defined. The cracking stress, cracking stress, expansion stress and peak stress are calculated by LSR. The mixture of soil and stone has the structure and similarity of mesostructures. It is a good idea to study the structural mechanics characteristics of soil-rock mixture based on the theory of fractal geometry, which can better understand the meso-structure of such geological materials Structure and mechanical properties.