Research On Load-bearing Mechanism And Stability Of Tension Anchoring System

The pre-tensioning anchoring technology is a new two-point pre-tensioning structure developed on the basis of pre-tensioning concrete technology and the principle of wedge anchors.This paper focuses on the energy storage mechanism and stability of the tension anchoring system,using theoretical analysis,numerical simulation,engineering practice methods,first designed a lock that matches the tension pre-tensioned anchor rod,and improved the tension jack and hold The lock agitator is conducive to the on-site implementation of the tension anchoring system.Secondly,from the perspective of energy conversion,the essential energy changes of the rock mass between loading and unloading are analyzed,and the energy storage mechanism of the tension anchoring system is studied.Industrial test for application.The main research contents are as follows:(1)The lock structure of the tension anchor is designed,which is different from the general nut fastening anchor.The anchor is tensioned by a tension jack.At the end of the tension,the inner wall of the anchor is tapered by the elastic force of the anchor.The anchor ring and the round table clamp are clamped in the direction of the rock body,and the tensile force is directly converted into prestress without loss of preload,which avoids the problems of uneven force and low torque efficiency caused by nut tightening.At the same time,the tension jack and the lock-type mixer are improved to make it compatible with the tension anchor system.(2)The variation of the energy in the rock body with the input of external energy is studied,and the curve of the energy change in the rock body when the loading-unloading process is repeated is established.It is divided into three parts to accumulate energy and increase energy dissipation.Three stages with energy release.Through the discrete element method numerical simulation software UDEC,three uniaxial compression models were established for the original rock mass,the rock mass installed with ordinary bolts and the high pretension bolts.The comparative analysis shows that the high pretension bolts can store energy in rock It has a promoting effect and can increase the internal energy storage of the rock system.(3)Establish a UDEC comparison model of the test roadway,and compare the deformation of the low pretension bolt roadway,medium pretension bolt roadway and the roadway with high pretension bolt installed,and pass the maximum principal stress and the minimum principal stress Stress,y-direction displacement,crack development and other aspects further describe the protective effect of high pretension bolts on rock mass deformation and failure.(4)Carry out industrial tests and propose a new support scheme for tensioned pretension bolts.Through on-site monitoring,use roof separation indicators to install and install tunnels with tensioned pretension bolts The comparative observation of the roadway of ordinary bolts is carried out to monitor the displacement of the roof,and it is finally concluded that the tensioned pretension bolts have good wall rock control capabilities.