Experimental Study on Shear Characteristics of Structural Plane with Different Fluctuation Characteristics

With the increasing scale and depth of underground engineering, geological environment that engineering is faced with becoming more complex. As weak position rock mass, structural surface has a particularly great influence on mechanical characteristics mass. In order to obtain shear strength characteristic plane analyze morphological parameters such as undulating angle bulge degree shearing, taking medium-low permeability tight sandstone research object, four kinds samples different angles (10, 20, 30 40°) were prepared Python high-precision engraving machine. Direct tests under normal stresses (2, 4, 6 8 MPa) rates (0.6, 1.2 2.4 mm/min) performed, properties analyzed. The surfaces before after shearing scanned using three-dimensional scanner, so evaluate roughness determine from various factors characteristics. test results showed for same angle, peak stress increased approximately linearly an increase in at 0.6 mm/min rate increment speed 0.82, while negatively correlated value 4 MPa stress. larger was, greater (the decreased by 2.31 40° angle). When fixed, corresponding gradually maximum was 5.04 rate. An analysis when (40°) (6 larger, damage became obvious, point closer tooth valley position, bite force friction better utilized. lower (0.6 mm/min), visible, increasingly sufficient, also greater.