Numerical and model experimental application study on the anchoring mechanism of tensile and compression composite anchor rods
In view of the limitation of the supporting effect of the full-length grouting anchor in the deep tunnel,in order to effectively control the deformation of the surrounding rock of the tunnel and enhance the bearing capacity of the anchor,this paper uses the finite element numeri-cal simulation method to study the interface failure characteristics and mechanical transmission mechanism of the tension-compression composite anchor support structure under the pull-out load the reinforcement of the rock tunnel,and applies the anchor to the overload model test to explore the supporting performance of the anchor.The results show that the mechanical evolution of the contact interface between anchorage body and surrounding rock has experienced the progressive failure process of elastic stage,plastic softening stage and slip stage.The transfer of shear force at the interface also appears at the bearing plate from the small drawing load,and transfers to both sides of the anchorage section with the increase of the drawing load,showing a bimodal trend.According to the shear stress distribution law of the bolt interface,the shear stress distri-bution model of composite bolt at low load and high load drawing is put forward.This model is u-niversal.The indoor overloading model test shows that the supporting effect of composite bolt is better than that of ordinary bolt.This study can value for the application of composite bolt in un-derground engineering such as deep tunnel.
tension-compression composite anchorprogressive failureinterface mechanical evo-lutionnumerical simulationmodel test