Structure surface normally owns highly directional properties caused by the properties of the material and the manufacturing process. Proper understanding of soil–structure interface behavior must recognize the structure surface’s highly directional properties and take into consideration its interactions with particulate material. To investigate the mechanical behavior of granular soil–structure interface under multi–directional shear tests, a shear orientation is defined to be an angle $\theta$ between the shear direction and the principal rough direction of the directional surface. Using the discrete element method, a series of 3D numerical interface shear tests was conducted, under seven shear orientations ($\theta$ = 0°, 10°, 30°, 45°, 60°, 75°, and 90°). The consistent response of macroscale shear behavior at the interface, loaded by various shear orientations, are presented from the perspectives of the resultant average shear stresses in $x$– and $y$– directions and soil volumetric strain. A determination of the thickness of the localized shear band in each specimen is followed by the discussion of particle displacement vector distribution. Furthermore, the evolutions of microscale properties inside and outside the localized shear band, such as the coordination number and material fabric provide a physical meaning or an explanation for the consistent macroscale shear behavior of granular soil–structure interface at a microscale level. The findings emphasize the importance of measuring the horizontal load in $x$– and $y$– directions when conducting experimental interface shear tests on rough surface with highly directional properties, because the resultant resistance corresponds to the true resistance of the granular assembly.

由于材料的特性和制造过程，结构表面通常具有高度的定向特性。对土壤-结构界面行为的正确理解必须认识到结构表面的高度定向性，并考虑其与颗粒材料的相互作用。为了研究多向剪切试验下颗粒状土-结构界面的力学行为，将剪切方向定义为一个角度$\theta$在剪切方向和定向表面的主要粗糙方向之间。使用离散元方法，在七个剪切方向下进行了一系列3D数值界面剪切测试（$\theta$ = 0°，10°，30°，45°，60°，75°和90°）。从产生的平均剪应力的角度给出了界面上宏观剪应力行为的一致响应，并加载了不同的剪应力。$X$–和 $ÿ$–方向和土壤体积应变。在确定每个试样中局部剪切带的厚度之后，讨论颗粒位移矢量分布。此外，局部剪切带内部和外部的微观尺度特性的演变，例如配位数和材料结构，为微观尺度的颗粒状土壤-结构界面的一致宏观尺度剪切行为提供了物理意义或解释。研究结果强调了测量水平荷载的重要性。$X$–和 $ÿ$–在具有高方向性的粗糙表面上进行实验性界面剪切测试时的方向，因为所得的电阻对应于颗粒组件的真实电阻。