Numerical Simulation Research Of Pre-Tensioned Bolts Reinforcing Roadway In Joint Rock Mass

The length, direction and angle of the joints exist in the rock mass are the critical factors to the rock mass condition. The rock engineering anchoring technique is great important in safety reinforcement. The principle research and design of the bolts support is not mature at present. The entire mechanical property of the joints rock mass after pre-tensioned bolts supporting should be studied basing on present theory foundation and applying to the rock mass engineering stability analysis.By means of FEA code ANSYS, build a deep joints rock mass roadway model, the strength criterion of the rock mass material is described by Drucker-Prager yield criterion, adopt contact unit to simulate a joint unit, the pre-tensioned bolts supporting joints coal roadway is researched. The pre-tensioned bolts supporting joints coal roadway is studied by different joints characteristic parameters (joint angle, joint length and joint space), different prestress and horizontal constant width joints roof. Made a systematic analysis to the simulation results and educe these conclusions:The reinforcement action of pre-tensioned bolts supporting joints rock mass mainly externalizes in creasing the interlayer-pressure and roadway roof pressure. The smaller the joint angle is; the closer the joint nears the middle of the roadway, the greater the compression stress increasing ratios of joint faces and stress relaxation areas are. The pre-tensioned bolts increase the joints pressure which is the mechanics of strengthening the joints roof. Thereby the joints sliding distance, the roof separation value and the roadway displacement is reduced. Pre-tensioned bolts support is an effective way to improve joint roof stability.