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岩石、结构性土、含水合物深海沉积土(能源土)等岩土材料均可视为由颗粒骨架和粒间胶结物共同构成的胶结型材料。简单实用的微观粒间接触模型是采用离散元数值方法分析胶结体系宏微观力学特性的基础。针对有一定厚度的粒间胶结形式,将胶结物简化为存在于颗粒之间有一定厚度的短圆柱。通过对胶结物内部应力分布进行适当简化推导了三维粒间接触模型,包括法向、切向、弯曲和扭转四个方向的相互作用规律。最终所得模型结合了理论推导和既有室内胶结接触力学试验成果,考虑粒间胶结物的法向压碎过程,能描述切向、弯曲和扭转单独作用的破坏过程以及剪弯扭共同作用下的破坏准则。模型形式简单,易于引入离散元程序。
Geotechnical materials such as rocks, structural soils and deep-sea hydrate-bearing sediments (energy soils) can all be considered as cemented materials composed of grain skeletons and intergranular cements. The simple and practical microscopic intergranular contact model is the basis of analyzing the macroscopical and mechanical properties of the cemented system by discrete element numerical method. For a certain thickness of the intergranular cementing form, the cement is reduced to a short cylinder with a certain thickness existing between the particles. The three-dimensional particle-to-particle contact model is derived by properly simplifying the internal stress distribution of the cements, including the law of interaction in the four directions of normal, tangential, bending and torsion. The resulting model combines the theoretical derivation with the existing laboratory cementing contact mechanics test results, considering the normal crushing process of the intergranular cement, describing the failure process of tangential, bending and torsion alone and the combined effect of shear bending and torsion Disruption guidelines. Model form is simple, easy to introduce discrete element program.