基于钻孔瓦斯流量和的压力测定有效抽采半径.pdfVIP

29 4 Vol.29 No.4 2012 07 Journal of Mining Safety Engineering July 2012 1673-3363-(2012)04-0596-051 1 2 1 2 1 230026 2 230022 0.74 MPa 30% 90 d 2.5 m TD 713 A Measurement of Effective Drainage Radius Based on Gas Flow and Pressure of Boreholes 1 2 1 2 YU Tao LU Ping SUN Jin-hua DENG Zhong 1State Key Laboratory of Fire ScienceUniversity of Science and Technology of ChinaHefeiAnhui 230026China 2Department of Safety EngineeringAnhui Institute of Architecture and IndustryHefeiAnhui 230022China Abstract In order to measure effective drainage radius exactly, we propose the method based on gas flow and pressure of boreholes. Under the index of remnant gas pressure less than 0.74 MPa and pre-drainage rate more than 30%, the computing formula is deduced based on the negative exponent attenuation law of gas flow, and the effective drainage radius is determined in combination with the variation of gas pressure. The method is applied in the arrangement of zonal pre-drainage boreholes. The effective drainage radius of different pre-drainage time and the utmost pre-drainage time are analyzed. Based on the premise that effective drainage radius reaches to 2.5 m in 90 pre-drainage days, the boreholes are designed to eliminate coal and gas outburst. The measurement method is demonstrated valid in outburst elimination by the examination of remnant gas pressure,pre-drainage rate and the zonal verification during the coal roadway driving. Key wo