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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。
The three-dimensional deformed body discrete element method can automatically retrieve the contact relation and discretizes the finite difference meshes of irregularly shaped coarse-grained soil particles and structures. Therefore, it has the inherent advantage of simulating the discrete-continuous coupling problem. Using random simulation technology to generate three-dimensional samples of coarse-grained soil, numerical experiments on the interface characteristics between coarse grained soil and structure were conducted based on the discrete element of the deformed body. The mechanical properties of the interface between the coarse grained soil and the coarse grained soil were compared. The mechanical properties of the contact surface under single-shear and direct-shear conditions were analyzed, and the numerical results were analyzed from the macro and micro aspects. The results show that the numerical test can well reflect the mechanical properties of the interface between the coarse grained soil and the structure, and the shear stress-relative shear displacement curve is similar to the experimental results. The influence of the contact surface roughness on the strength and deformation characteristics of the contact surface Large, the mechanism is that the shear disturbance on the specimen is different; shear stress and relative shear displacement under the direct shear and single shear state are hyperbola, the initial shear stiffness of single shear test is lower than the direct shear test, Two kinds of tests to get the contact surface shear strength index is relatively close.