In-situ soil deposits often have an initial shear stress that significantly affects their subsequent cyclic behavior and liquefaction susceptibility. This is closely related to the internal structure of the soil but is very difficult to study thoroughly through conventional laboratory tests. In this study, a numerical procedure that can impose arbitrary two-dimensional stress or strain paths was developed using the discrete element method (DEM); this procedure was then used in simulations to investigate the behavior of granular polygonal samples under an undrained cyclic simple shear with various densities and stress conditions. Two types of cyclic responses could be identified from the simulation results: “cyclic liquefaction” and “residual deformation failure.” It was found that the initial static shear could either enhance or weaken the cyclic resistance of sand to liquefaction failure, depending on the extent of the shear stress reversal. The internal structure of the granular materials was quantified using a contact-normal-based fabric tensor that could describe their load-bearing characteristics in response to the external applied stress. The norm and principal direction of the fabric tensor both exhibited drastically different evolution patterns under varying loading conditions. This can provide further insights into the underlying failure mechanism of granular soils.

原位土壤沉积物通常具有初始剪切应力，这会显着影响其随后的循环行为和液化敏感性。这与土壤的内部结构密切相关，但是很难通过常规实验室测试来全面研究。在这项研究中，使用离散元方法（DEM）提出了可以施加任意二维应力或应变路径的数值程序。然后将该程序用于模拟，以研究具有各种密度和应力条件的不排水循环简单剪切作用下的粒状多边形样品的行为。从模拟结果中可以识别出两种类型的循环响应：“循环液化”和“残余变形破坏”。人们发现，初始静态剪切力可能会增强或减弱砂土对液化破坏的循环阻力，具体取决于剪切应力反转的程度。粒状材料的内部结构使用基于接触法线的织物张量进行量化，该张量可以描述其响应于外部施加应力的承载特性。在变化的负载条件下，织物张量的范数和主方向都表现出截然不同的演变模式。这可以进一步了解颗粒状土壤的潜在破坏机理。粒状材料的内部结构使用基于接触法线的织物张量进行量化，该张量可以描述其响应于外部施加应力的承载特性。在变化的负载条件下，织物张量的范数和主方向都表现出截然不同的演变模式。这可以进一步了解颗粒状土壤的潜在破坏机理。粒状材料的内部结构使用基于接触法线的织物张量进行量化，该张量可以描述其响应于外部施加应力的承载特性。在变化的负载条件下，织物张量的范数和主方向都表现出截然不同的演变模式。这可以进一步了解颗粒状土壤的潜在破坏机理。