初始静剪应力下土与结构接触面静力特性研究

EXPERIMENTAL STUDY ON 3D MONOTONIC BEHAVIOR OF A GRAVEL-STRUCTURE INTERFACE CONSIDERING INITIAL SHEAR STRESS

运用80t三维多功能土工试验机对粗粒土与结构接触面在一定初始静剪应力下的三维单调力学特性进行了试验研究。结果表明:接触面在不同剪切方向下均先剪缩后剪胀,剪胀主要在加载后期接触面接近和达到抗剪强度、切向位移较大时产生;接触面切向变形存在非共轴现象,切向位移增量方向随剪切的进行与切向应力逐渐靠近;切向位移间关系基本为直线,且其与初始静剪应力间的夹角和剪切方向角存在良好的数学关系;接触面抗剪强度包线基本为圆形,呈各向同性;剪切方向对接触面剪缩量、体变与切向位移关系、体变与切向应力关系及切向应力-应变关系有较大影响。

Using a large-scale professional apparatus, the 3D monotonic behavior of the interface considering initial shear stress is investigated, which is between a steel plate and gravelly soil widely, used in Geo-engineering. The test results show that： 1） the interface compresses at the start of shear application and then dilates when the shear stress is close to shear strength and the tangential displacement is large enough; 2） the non-coaxial behavior of the interface is obviously observed in tangential deformation when the initial shear stress is considered, and the non-coaxial angle decreases as the shear application continues; 3） the displacement relationship in x-direction and y-direction appears as a line, and the angle between the line and initial shear stress has a good relationship with the angle between shear direction versus initial shear stress; 4） the envelope of peak shear strength is nearly circular, revealing that the interface is isotropic in shear strength; 5） the angle between shear direction and initial shear stress impacts a significant influence on the compression, the normal and tangential displacement relationship and the shear stress-strain relationship of the interface.