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运用80 t大型三维接触面试验机,对单剪条件下粗粒土与钢板接触面静动力学规律进行了研究。随单调剪切的进行,接触面土体变形由靠近结构面区域逐渐向远处传递和发展,并集中于剪切区域内,接触面厚度约为(6~7)D50;接触面达到强度时对应的滑动位移约为0.5D50,之后滑动位移发展变快,破坏发生在接触界面处;法向应力对接触面厚度、土体变形沿试样深度分布形式影响较小,主要影响土体变形大小。循环剪切时接触面厚度未继续扩展;土体变形及变形位移幅值随循环剪切逐渐减小,并向初始剪切方向偏移,出现了异向性;接触面在不断剪切硬化,主要由结构面附近土体硬化所致;接触面强度是否达到主要取决于滑动位移,并在达到后逐渐减小,减小程度达16%,且正反向剪切时强度呈现异向性;接触面剪切体变、切向应力与3种位移(切向位移、变形位移、滑动位移)的关系稍有差别。
The 80 t large three-dimensional contact surface testing machine was used to study the static and dynamic laws of the interface between coarse-grained soil and steel under single-shear conditions. With the monotonous shearing, the soil deformation of the contact surface gradually passes from the area close to the structural plane to the distant place and is concentrated in the shearing area. The contact surface thickness is about (6-7) D50. When the contact surface reaches the strength The corresponding sliding displacement is about 0.5D50, and then the sliding displacement develops faster and the failure occurs at the contact interface. The thickness of the normal stress on the contact surface and the soil deformation have a smaller effect on the depth distribution of the specimen, which mainly affects the deformation of the soil body . The thickness of the contact surface did not continue to expand when the cyclic shear was applied. The amplitude of deformation and deformation displacement of soil decreased with the cyclic shear and shifted to the initial shear direction. The anisotropy appeared. The contact surface was continuously sheared and hardened, It is mainly caused by the hardening of soil near the structural surface. Whether the strength of the contact surface mainly depends on the sliding displacement and decreases gradually after it reaches the degree of decrease is up to 16%, and the strength is opposite when shearing forward and backward; There is a slight difference between shear deformation of the contact surface, tangential stress and the three displacements (tangential displacement, deformation displacement, sliding displacement).