Direct shear test on the interface between concrete and bedrock of dam foundation of a reservoir

The weak failure surface of the dam body and the bedrock cementation surface is one of the key points of dam safety research at home and abroad. The direct shear strength of the contact surface between the dam foundation concrete and the bedrock is used as the current research on whether the dam will "slip" along the contact surface. Based on this, many different methods are used at home and abroad to determine the direct shear strength. In this paper, through the excavation of the dam foundation rock and on-site rock structure samples, 5 sets of 25-point in-situ direct shear tests on the interface between concrete and bedrock were carried out on the medium-thick-thick feldspar quartz sandstone of the main rock mass of the dam foundation to determine the dam foundation. Mechanical parameters of rock mass. Based on the results of field experiments, some reference opinions for field direct shear tests and direct shear strength selection in engineering design are put forward, which also provide a basis for subsequent numerical simulation calculations.