论文部分内容阅读
基于三维变形体离散单元法,模拟堆石体的真三轴试验,研究堆石体在三向不等应力状态下的强度和变形特性。真三轴数值试验装置采用六刚性板加荷方式,等中主应力比路径加载。数值试验结果表明:真三轴数值试验能较好反映堆石体在三向不等应力状态下的应力和变形规律,数值模拟得到宏观应力变形特性与试验规律相似;等中主应力比参数(2 3 1 3b=(σσ)(σσ))的大小对堆石在三向应力状态下应力和强度特性有显著的影响,堆石体在3个加载方向的变形也随该参数的变化而变化,应力比参数b从0到1变化过程中中主应变方向先压缩后膨胀,小主应变方向一直处于压缩状态;堆石体的内摩擦角随着b值的增加而增大,基本符合Lade-Duncan破坏准则;在细观层面上,围压越高,b值越大,颗粒配位数越大;加载过程中,颗粒接触法向和法向接触力各向异性程度加强,各向异性主方向角由水平向转向大主应变方向,试样各向异性系数的演化规律和试样的宏观应力变形曲线相对应,试样的宏观力学特性与细观组构存在内在的关联。
Based on the three-dimensional deformation body discrete element method, the true triaxial test of the rockfill body is simulated to study the strength and deformation characteristics of the rockfill body in three-dimensional unequal stress state. True three-axis numerical test device using six rigid plate loading method, such as the main stress than the path of loading. The results of numerical experiments show that the true triaxial numerical test can better reflect the stress and deformation of rockfill in three-dimensional unequal stress state. The numerical simulation results show that the macro-stress deformation characteristics are similar to the experimental ones. 2 3 1 3b = (σσ) (σσ)) has a significant effect on the stress and strength properties of rockfill under three-dimensional stress conditions. The deformation of the rockfill in three loading directions also varies with the parameter , The stress ratio of the parameter b from 0 to 1 during the main strain direction of the first compression and expansion, the direction of the small main strain has been in compression; rockfill internal friction angle increases with the b value increases, basically in line with Lade -Duncan failure criterion; at the meso-level, the higher the confining pressure, the larger the value of b, the larger the coordination number of the particles; the greater the degree of anisotropy of the contact normal and normal contact force during the loading process, The main direction angle changes from horizontal direction to the main strain direction. The evolution law of the anisotropy coefficient of the specimen corresponds to the macroscopic stress-strain curve of the specimen. The macroscopic mechanical properties of the specimen are intrinsically related to the meso-structure.