Development and Application of Cooperative Reinforced Cyclic Shearing Device for Rock Mass Structural Plane

In order to study the mechanical properties of rock mass structural planes under cyclic action, a cooperative reinforced cyclic shear configuration is proposed on the basis of investigation of existing cyclic shear equipment. The main functions, equipment composition and technical indicators of the developed multifunctional cyclic shearing device for rock mass structural planes were introduced in detail, and a series of rock mass structural plane tests were carried out. The cyclic shearing device mainly includes three parts: test device, power system, control and acquisition system. The maximum normal compressive stress is up to 60 MPa; the maximum cyclic shear stress is up to 100 MPa. The maximum size of sample can be 150 mm×150 mm×150 mm; The equipment takes more into account the research needs of cyclic shear test of structural plane. The device is designed for various mechanical tests of rock mass structural plane, including uniaxial compression test, the normal cyclic loading and unloading test, the monotonic shear test under various control modes. More importantly, the variable path cyclic shear test of structural plane can be carry out by the equipment. The experimental data are collected smoothly and the curve is smooth, which proves the effectiveness and accuracy of the developed equipment. The cyclic shear tests of rock mass structural plane under multi-factor variables are carried out by using the device. The results show that: The mechanical properties of cyclic shear of the structural plane are closely related to the normal stress, the roughness of the structural plane, the cyclic shear rate and the cycle number. Combined with a three-dimensional scanner, the three-dimensional texture scanning of the sample before and after the test is carried out. Then their three-dimensional digital terrain was established. Finally, the progressive failure process and failure modes of the structural plane in the cyclic shear were studied. The relevant research results will provide technical support for the study of the mechanical failure mechanism and constitutive model of the rock structural surface under the action of cyclic loading.