Analysis on mechanical performance and supporting function of rock bolt plates

The loading states,stress distribution,deformation and supporting effects of bolt plates were studied by the combination method of laboratory tests,numerical modeling and field monitoring.The gauged plates were designed and manufactured in the laboratory,the relation between deformation,stresses of domed plates and loads under different supporting states were measured,and the loads,at which the plates start to yield,were obtained.By means of finite element method,the stress distribution features of domed plates under the supporting states of face contact,four sides,four points and three points were analyzed.The numerical model with single bolt anchored in the center of surrounding rock,which can simulate the stress field caused by bolt pretension,was built.The affects of plates to the stress field caused by bolt pretension,stress distribution in the plates,and the supporting effects of the plates to surrounding rock were discussed.The gauged plates were applied,and the stresses in the plates were monitored in underground extraction entries in the Tunliu Coal Mine,the Lu'an coal mining district.The stress distribution features and variation laws in the plates in the stages of bolt pretension,driving affect and stabilization were preliminarily analyzed.