中文摘要：

三维变形体离散元法能够自动检索接触关系,并对具有不规则形状的粗粒土颗粒和结构物进行有限差分网格离散,因此,具有模拟离散-连续耦合问题的先天优势。采用随机模拟技术生成粗粒土三维数值试样,基于变形体离散元进行粗粒土与结构接触面特性的数值试验,研究了不同接触面粗糙程度的接触面力学特性,对比了粗粒土与结构物在单剪和直剪状态下的接触面力学特性,从宏观和细观两个层面分析了数值试验结果。结果表明,数值试验能较好地反映粗粒土与结构接触面的力学特性,其剪应力-相对剪切位移曲线与试验结果规律相似;接触面粗糙程度对接触面的强度和变形特性影响较大,其机制在于剪切对试样的扰动程度不同;直剪和单剪状态下试样剪应力-相对剪切位移均为双曲线,单剪试验的初始剪切刚度低于直剪试验,两种试验得到接触面抗剪强度指标比较接近。

英文摘要：

Three-dimensional deformable discrete element method is an appropriate numerical method for studying mechanical behavior of discontinues geo-material.The ability of automatic contact detection and discretization of particle and structure by finite difference grids,makes it had inherent advantages in simulation discrete-continuum coupling problem.The deformable discrete element method is employed to study the mechanical behavior of soil-structure interaction problem,in which the coarse-grained soil is modeled by random simulation technique.The mechanical behavior of interface between soil-structure is compared under direct shear and simple shear conditions.The numerical simulation results are investigated from macroscopic and mesoscopic levels,respectively.The results show that the numerical simulation can reflect the mechanical behavior of soil-structure interface;the curves of shear stress-relative shear displacement have a good agreement with the experimental results;the interface roughness has a great impact on the strength and deformation properties,due to the disturbance of particle induced by shear.The shear stress-relative shear displacement relationships of simple shear and direct shear are both hyperbolic.The initial stiffness of simple shear is smaller than that of direct shear;and the shear strength of two are similar.