The Mathematical Model And The Visualization Of The Pressure Relief And Drainage Drilling In The Cross Adit Coal Uncovering And Subvertical Coal Uncovering

Coal and gas outburst is a kind of complex mine dynamic phenomena, which can often bring serious impact and destruction to the work of the coal mine when it happened. Most coal and gas outburst happen at cross adit coal uncovering in coal mine, so coal uncovering outburst is one of the main outburst model. Under the current technology level of development in our country, drainage of coal gas by cross-seam drilling is main local outburst prevention measures of coal uncovering in coal mine, the implementation of these measures has prevented and controlled coal and gas outburst effectively. But in actual, the bases of choice of drilling layout parameters are not uniform, there is no complete accurate theoretical formula to support the layout parameters and often combined with different experience of designers, this reduces the effectiveness of the pressure relief and drainage drilling and led to the increase of the cost. And with no completely implementation of the computer calculation automatically for drilling layout parameters, it takes too long time in actual calculation and sometime exists error. Besides, all of the current working drawings of pressure relief and drainage drilling are two-dimensional, they can not show visual graphs of drilling layout of coal uncovering directly.Therefore, the paper aims at accuracy and speediness to calculate the pressure relief and drainage drilling parameters for cross adit coal uncovering and subvertical coal uncovering and plot related visual graphs conveniently, and also optimize the drillings’number. And all of these work are under different position of roadway and coal seam. Firstly, the mathematical model of cross adit coal uncovering is built by calculation methods of vector angle, plane equation, etc in analytic geometry. Secondly, the visual model of3D roadway,3D drilling and3D coal seam are created by AddRegion, AddExtrudeSolidAlongpath, Rotate3D and other methods in AutoCAD. Finally, we program and design the user interface by means of VBA so that design parameters are worked out and visual graphs are plotted automatically by inputting different basic parameters in the interface after running the program on the computer. The model can work out the length of drillings at the front or the back of coal seam, the dip angle of drillings, the row and column spacing of drillings at working face, the number of all drillings, and other design parameters under different conditions of dip angle and bearing of coal seam, the dip angle of roadway, the seam thickness and so on. At the same time, the concluded visual graphs and layout parameters are exported to Excel form, and they are very close to the actual condition, which can guide the layout work of pressure relief and drainage drilling for cross adit coal uncovering and subvertical coal uncovering directly and be used as a reference for designers of gas drainage drilling.