Shear behavior of two-order morphology in rock joints

Two-order morphology of rock joints named as waviness and unevenness can be separated by morphology classification method, which plays a decisive role in the evolution of shear stress during the shear test. The joint morphology is obtained by using 3D printing and 3D laser scanning techniques and the joint model samples in two-order morphology are produced by cement mortar. Then, shear tests are performed under different normal loads. Results shows that the waviness is dominant in the total morphology during the shear test, and the shear contribution of unevenness mainly occurs in the climbing phase of shearing process. Comparing the failure modes of two-order morphology, waviness mainly embodies shear dilation characteristics and unevenness mainly shows shear wear characteristics. Based on this, a quantitative parameter is proposed to represent the ratio of the peak shear strength of the two-order morphology to that of total morphology. The functional relationship between the peak shear strength of total and two-order morphologies is determined, providing a theoretical method for further in-depth study on the shear strength of the interaction with two-order morphology of rock joints.