中文摘要：

采用改进的DRS-I型高压直剪仪进行了砂砾与不同形貌尺度的粗糙钢板结构面接触剪切试验，获得不同压力、形貌尺度条件下的剪切试验结果，分析了中、高压下的不同结构面形貌尺度与砂土颗粒平均粒径比值R（R=H／d50，相对形貌尺度）对接触面剪切特性的影响。结构面相对形貌尺度R直接影响接触面剪切过程中的力学与体变特性，中压与高压下分别呈现不同的影响规律且存在各自的峰值相对形貌尺度Rmax与稳定相对形貌尺度Rst。达到峰值相对形貌尺度之前，尺的增大使得接触面剪切耗能随之增加，而剪切体变在中压、高压下分别随之增加和降低；稳定相对形貌尺度之后，接触面剪切耗能与剪切体变达到稳定状态，随R的增大呈微小变化，变化幅值较小。上述规律与接触面附近一定区域的颗粒变位及破碎等机制密切相关，获得成果将为研究不同法向压力下受形貌尺度影响的结构面相对粗糙度问题提供新思路，对于研究不同法向压力下粗粒土与粗糙结构面的接触面力学与变形机制有一定借鉴意义。

英文摘要：

By modified DRS-I high pressure direct shear test apparatus, interface shear tests of gravel and different structural planes under medium and high pressures are carried out. With different structural planes having different peak-valley distances H, relative scale R is defined as the ratio of H to average particle size （ R = H / dso ）. Effects of relative scale R on mechanical and deformation characteristics of interface shear process under medium and high pressures are studied. The test results show that the relative scale R affects the interface shear energy consumption and shear volume deformation directly; and influential rules are different between medium pressure and high pressure. Whether under medium or high pressure, there exist limited and critical R respectively described as Rm~ and Rst Before Rm~, the increase of R results in monotonous change of interface shear energy consumption and shear volume deformation. After R~a~, the increase of R will cause shear energy consumption and shear volume deformation meeting a critical state, and the corresponding relative scale is Rst. For above rules closely relate to particle displacement and grain breakage, the limited and critical values of R give new thoughts to research the roughness which affected by relative scale of particles and structural planes under different pressures; and it also has some significance for describing the mechanics and deformation mechanism of interface under different pressures.