Shear Behavior of Silty Clay–Concrete Interface Based on Large-Scale Direct Shear Test
Junchao Yang, Yuanyou Xia, Wudi Chen, Lei Zhang, Lihua Li
Abstract
This paper presents the results of an experimental study on saturated silty clay–concrete interface shear behavior, and a shear strength prediction model is established for the silty clay–concrete interface. Based on three-dimensional (3D) scanning data of actual concrete pile surfaces, regular and irregular concrete surfaces with different roughnesses are replicated in the laboratory tests. The interface shear strength is found to increase as the roughness coefficient of concrete increases; the shear process of a regular interface shows a strain softening feature, while that for an irregular interface shows strain hardening. The effect of a normal stress increase on the residual strength of a regular interface is more obvious. The modified Grasselli roughness evaluation method is reasonably effective in characterizing both regular and irregular contact surfaces. In the framework of this method, a prediction formula for the estimation of peak strength of a clay–concrete interface is proposed, which performs favorably well in comparison with test results obtained from this and previous studies.