Shear Failure Characteristics Of Grouting Joints In Rock Mass

In order to ensure the safety of the construction process,the natural rock body with cracks will be reinforced as necessary.Grouting is one of the common methods.The injected slurry solidifies to form a filling,and the presence of the filling material affects the joint rock.The mechanical properties have a greater influence.Therefore,it is very important to study the influence of the strength and thickness of the filling on the mechanical properties of jointed rock mass.The main research contents of this article are as follows:(1)Four cement mortar materials with different strengths and gradient changes were prepared by using cement mortar materials through ratio test,and the ratio of cement mortar with similar mechanical properties to shale was determined,and this ratio cement mortar was used to make joint rock The remaining three strength cement mortar materials are used as grouting fillers.By changing the strength of cement mortar,the thickness of the filling and the angle of fluctuation of the joint,the influence of these conditions on the failure mode and mechanical properties of the sawtooth joint surface was studied.(2)According to the geometry of the joint surface,establish a two-dimensional mechanical model of the grouting filling sawtooth joint surface,and analyze the expression of the ultimate shear stress under different failure modes of the rock mass grouting joint.The effects of the strength and filling degree of the cement mortar on the shear strength of the grouting joints in the rock mass are theoretically analyzed.(3)Based on the laboratory shear test,a numerical simulation model was established using the particle flow program-PFC2 D to perform a numerical simulation shear test on the specimen.Under different normal stresses,the effects of grouting filling degree,grouting filling cement mortar strength and jagged joint fluctuation angle on rock mass grouting joint failure mechanism and crack propagation path were analyzed.