Research On End Anchoring-grouting Prestressed Anchor Support Technology

As a result of the mining depth increasing, orebody extraction becomes more difficult. Stope and tunnel support are paid more attention to in mine to ensure security. End anchoring-grouting prestressed anchor are widely used in mine support as its easy construction and active support. To further understand the anchoring characteristics of end anchoring-grouting prestressed anchor, a series of important conclusions were obtained by means of theoretical analysis, on-situ monitoring and numerical simulation, with the project background of V# ore safe stoping in xincheng gold mining. Research contents and conclusions are as follows:(1) Based on the theory of extrusion and reinforcement, the equations of the anchorage range were obtained by the research of end anchoring-grouting prestressed anchor. The related properties of anchorage range equations were analysed, thus to obtain the optimum anchor space and the anchorage outer zone corresponding to the variety of working conditions which are commonly used in mines. Based on the study of block theory, the stability of roof in xincheng gold mine was analysed, which showed that the key blocks were on the verge of stable after bolt support.(2) Monitoring scheme was designed for the supporting roof in stope, based on the test of stope 63762 in xincheng gold mine. The data of roof rock movement and axial force of anchor were achieved. The laws of roof rock movement and anchor axial force changing with time and space were obtained by analysing and computing the monitoring data. The prediction models were established by time series, which showed that the existing support way can effectively control mass displacement and ensure the safety and reliability of the stope roof.(3) The approximate experimental simulation and on-situ exploitation simulation of end anchoring-grouting prestressed anchor were done by FLAC3D. Simulation results were analysed, and simulation results and monitoring data were compared. The results show that:a reinforced plate was formed on the free face by blot supporting with reasonable parameters; in the high sub-stope mining, not only the safety of the roof, but also edges rock falling should be considered.