Study On Anchor(Cables) Supporting Parameters Design In Large Span Open-off Rectangular Roadway

Coal mining technology in China increase rapidly, large and high longwall caving face equipments have been used. As a result of it is power increase and volume is bigger that mining and excavation equipment. In order to satisfy it is demand of ventilation and transportation of stoping and excavation during the mine production, roadway section size and span are increased significantly. While the existing theory of bolt and anchor reinforcement theory there are many defects in the anchoring support operation process of large span open-off and heavy section roadway, there are difficult in field application, which can’t meet the needs of the scientific management of bolt and anchor support. So it need to study bolt and anchor support parameters design method that suitable for large span open-off and heavy section roadway, further improve the supporting theory of bolt and anchor.The paper is equivalent the rectangular roadway to a flat ellipse based on the existing bolting theories. We studied the loose and destroy zone of the surrounding rock of rectangular roadway after analyzing the plastic zone of ellipse by applying the theory of elastic-plastic limited equilibrium, then we determined anchor(cables) supporting parameters. That provides a new design idea for determining supporting parameters of large span open-off rectangular roadway.The paper took YanAn city CheCun coal302large span open-off rectangular roadway for example to determine bolt and anchor supporting parameters for large span open-off rectangular roadway. We first analyzed the engineering characteristics of the large span roadway,then proposed equivalent ellipse method. And we compared the design parameters that equivalent ellipse method proposed in this paper and the existing caving arch method and equivalent circle method. On this basis we determined bolt and anchor supporting parameters. We used the parameters to analyze supporting effect by Flac3D numerical simulation software. On basis of it, the supporting parameters was used in roadway support construction; finally, we monitored anchor(cables) supporting effect; analyzed and evaluated monitoring data, then the result is fed back to design, to achieve the combination of theory and practice.From the results of the engineering practice, it is accurate that the plastic range of rectangular roadway through the equivalent ellipse method proposed in this paper. It is close to the actual situation that anchor(cables) supporting parameters of large span open-off rectangular roadway determined by equivalent ellipse method, obviously improve the support strength and effect. The method has high application value, and it’s very well solute CheCun coal ming302large span open-off rectangular roadway support problem. It is provide more Simple and practical methods for large span open-off roadway supporting.