Study On The Mechanical Properties Of Bolted Joint And Its Slope Stability

With the development of infrastructure, jointed slope stability becomes a problem in the increasing slope engineering. To solve this problem, anchor reinforcement technology is widely used as the most common means. However, because of the complexity and diversity of geological body, the current bolting theory still has some deficiencies in engineering practice. Therefore, it is very significant to continue studying the theory about the reinforcement effect of bolts.On the theory that jointed slope stability and strength are usually dependent on the behaviors of joint surface, this paper studies on the joint surface from the macroscopic and microscopic view. From the macroscopic view, the impact of its traits on jointed slope failure types is analyzed. From the microscopic view, mechanical properties of the weak joint surface are studied. Based on the principle of geological progressive failure, a calculation model of progressive failure for flat joint surface is established to describe joint shear properties reasonably. Strength formula of bolted joint surface is also proposed by considering anchored reinforcement. It is reflected that shear bolt support theory is suitable to describe the support mecha nism of bolt jointed slope, which means that anchored reinforcement on jointed slope could be equivalent to “cohesion” of joint plane. The conclusion is applied to stability analysis of anchor plane in jointed slope in order to obtain calculation formula o f stability coefficient which includes anchor shear effect. The formula could also quantitatively reflect anchor reinforcement from safety factor. Jointed rock slopes under the conditions of non-support or bolt support are simulated with the FEM software ANSYS. By comparing displacement, stress and stability coefficient, the result shows reinforcement effect of anchor on jointed slope, and verifies feasibility and applicability of the formula of stability. Finally, two designs of full resin bolt to support jointed rock slopes are used in an engineering example, it turns out that the one which considers the combined effect of axial and tangential is more reasonable and perhaps save steel consumption.