关键词: 接触面, 粗粒土, 循环特性, 初始静剪应力, 直剪试验

Abstract: Applied with a new professional apparatus, the 3D cycle mechanical behavior of a gravel-structure interface is investigated considering initial static shear stress. The tangential displacement in the direction of initial static shear stress is obviously observed due to the cyclic shear application; it has a linear relationship with its perpendicular shear distance. The angle between the line and the initial static shear stress behaves in quadratic polynomial manner with initial static shear stress level. The magnitude of initial static shear stress has little influence on the shear strength and the relation pattern between tangential shear stress and strain, but has significant effect on the peak perpendicular shear stress, volumetric change and the relationship between volumetric change and tangential displacement of the interface. As the initial static shear stress increases, the peak perpendicular shear stress and the corresponding tangential displacement of the interface decrease, the interface becomes more hardened due to cyclic shear application, and dilates more at the beginning of shear application while less during subsequent cyclic shearing.

Key words: interface, gravelly soil, cycle mechanical behavior, initial static shear stress, direct shear test