Research On Disaster Prevention And Control Technology For Speedy Drivage Of Coal Drift In High Stress And High Outburst Area

The first coal face in Shoushan No.l mine locates in high stress and high outburst area. Coal drift in this area has the characteristics of large mining depth, high ground stress, high gas content and high outburst danger, so its driving speed is most slow, and the work of excavation replacement and safety production has been affected seriously by it, it is necessary to explore an effective technology suitable for preventing and controlling disaster during the driving process of coal drift in high stress and high outburst area. Therefore, disaster prevention and control technology for speedy drivage of coal drift in high stress and high outburst area is studied roundly by means of theoretic analysis, numerical simulation, laboratory experiment and industrial test in this paper.The main research contents of this paper are as follows:1. Based on test results of physical-mechanical properties of rock, surrounding rock mass mechanics properties of gateway are researched by adopting Hoek-Brown strength failure criterion and W. Dershowits empirical method; Based on geomechanics theory, surrounding rock control features of gateway are analyzed.2. Under the guidance of the bolting surrounding strength reforcement theory and bolt & anchor intensive support theory, support system of gateway in high stress and high outburst area is founded according to surrounding rock control features; then numerical simulation study of effect on surrounding rock deformation of high stress coal drift by different support parameters and form is carried out by discrete element code UDEC, and the first-rank coordination support system of bolt and cable is founded ultimately.3. Based on gas geology theory, geological structure form and its influence on gas existence are analyzed; Based on gas prevention and control theory, the general outburst prevention system is founded, whose core is presplitting blasting technology using borehole through layer of high level suction roadway.4. Type approval test is carried out in Shoushan No.l mine, test results indicate that disaster prevention and control technology can prevent roof accident and outburst accident effectively, and drive speed of coal drift increases greatly, safety and speedy drivage of coal drift in high stress and high outburst area is able to realize.The main innovations of this paper are as follows:1. According to surrounding rock control features of gateway, support system is founded which includes coordination support technology using bolt & cable which has high prestress and high intensity, and section set in advance. The system is applied successfully, displacement of roadway's sides reduces 41.9%, sinking displacement of roof reduces 52.4%, and surrounding rock deformation in high stress and high outburst area is controlled efficiently.2. Aim at the situation that return airway and its high level suction roadway influence each other, uncovered roof is most fragmentized, and support conditions are very difficult, study on the change law of surrounding rock stress between above-mentioned roadway is carried out by using explicit finite difference program FLAC. Research results indicate that surrounding rock stress superposes badly when horizontal range of the two roadway is 10 m. Therefore, roadway layout is changed, support conditions and roof integrality become well when horizontal range of the two roadway is 15 m.3. The general outburst prevention system is founded, whose core is presplitting blasting technology using borehole through layer of high level suction roadway, beyond that, geological borehole for advanced detection, advancing hole used for gas exhaust, borehole through layer of high level suction roadway for forepumping, and gas automatic monitoring system are included. Experiment results indicate that the system can prevent and control coal and gas outburst in high stress and high outburst area.4.-Research findings of this paper is applied successfully, monthly mean drive speed of return airway improves 91.5% than previous speed, and haulage roadway improves 59.5%. drive speed record of coal drift in high stress and high outburst area in Pingdingshan mining area is set up.