Principles of the roof cut short-arm beam mining method (110 method) and its mining-induced stress distribution
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摘要
Since the 1960 s, mining science and technology in China has experienced two technical innovations, i.e.the ‘‘Masonry Beam Theory(MBT)" and ‘‘Transfer Rock Beam Theory(TRBT)". Based on those theories, the conventional mining method(being called the 121 mining method) was established, consisting of excavating two tunnels with a pillar left for mining a working panel. However, with increasing mining depth,engineering geological disasters in the underground caverns have been frequently encountered. In addition, the use of the coal-pillar mining results in a large amount of coal resources unexploited. In order to address the problems above, the ‘‘Roof Cut Short-Arm Beam Theory(RCSBT), being called the 110 mining method)" was proposed by He Manchao in 2008. The 110 mining method features the mining of one coal seam panel, excavating necessarily only one roadway tunnel and leaving no pillars. Realization of the 110 mining method includes the following steps:(1) directional pre-splitting roof cutting,(2) supporting the roof by using high Constant Resistance Large Deformation bolt/cable(CRLD), and(3) blocking gangue by hydraulic props. This paper presents an overview of the principles, techniques and application of the 110 mining method. Special emphasis is placed on the numerical simulation of the geostress distribution found in the mining panel using the 110 method compared to that of the 121 method. In addition, the stress distribution on the ‘‘short beam" left by the roof cutting when performing the 110 method was also investigated using both numerical simulation and theoretical formulation.
Since the 1960 s, mining science and technology in China has experienced two technical innovations, i.e.the ‘‘Masonry Beam Theory(MBT)" and ‘‘Transfer Rock Beam Theory(TRBT)". Based on those theories, the conventional mining method(being called the 121 mining method) was established, consisting of excavating two tunnels with a pillar left for mining a working panel. However, with increasing mining depth,engineering geological disasters in the underground caverns have been frequently encountered. In addition, the use of the coal-pillar mining results in a large amount of coal resources unexploited. In order to address the problems above, the ‘‘Roof Cut Short-Arm Beam Theory(RCSBT), being called the 110 mining method)" was proposed by He Manchao in 2008. The 110 mining method features the mining of one coal seam panel, excavating necessarily only one roadway tunnel and leaving no pillars. Realization of the 110 mining method includes the following steps:(1) directional pre-splitting roof cutting,(2) supporting the roof by using high Constant Resistance Large Deformation bolt/cable(CRLD), and(3) blocking gangue by hydraulic props. This paper presents an overview of the principles, techniques and application of the 110 mining method. Special emphasis is placed on the numerical simulation of the geostress distribution found in the mining panel using the 110 method compared to that of the 121 method. In addition, the stress distribution on the ‘‘short beam" left by the roof cutting when performing the 110 method was also investigated using both numerical simulation and theoretical formulation.
Since the 1960 s, mining science and technology in China has experienced two technical innovations, i.e.the ‘‘Masonry Beam Theory(MBT)" and ‘‘Transfer Rock Beam Theory(TRBT)". Based on those theories, the conventional mining method(being called the 121 mining method) was established, consisting of excavating two tunnels with a pillar left for mining a working panel. However, with increasing mining depth,engineering geological disasters in the underground caverns have been frequently encountered. In addition, the use of the coal-pillar mining results in a large amount of coal resources unexploited. In order to address the problems above, the ‘‘Roof Cut Short-Arm Beam Theory(RCSBT), being called the 110 mining method)" was proposed by He Manchao in 2008. The 110 mining method features the mining of one coal seam panel, excavating necessarily only one roadway tunnel and leaving no pillars. Realization of the 110 mining method includes the following steps:(1) directional pre-splitting roof cutting,(2) supporting the roof by using high Constant Resistance Large Deformation bolt/cable(CRLD), and(3) blocking gangue by hydraulic props. This paper presents an overview of the principles, techniques and application of the 110 mining method. Special emphasis is placed on the numerical simulation of the geostress distribution found in the mining panel using the 110 method compared to that of the 121 method. In addition, the stress distribution on the ‘‘short beam" left by the roof cutting when performing the 110 method was also investigated using both numerical simulation and theoretical formulation.
引文
[1]Qian MG.The equilibrium condition for overlying strata in the stope.J China Inst Min Technol 1981;2:31–40.
[2]Qian MG.The structural model of overlying strata in the stope and its application.J China Inst Min Technol 1982;2:1–11.
[3]Qian MG,Li HC.The movement of overlying strata in longwall mining and its effect on ground pressure.J China Coal Soc 1982;2:1–12.
[4]Song ZQ.Basic rules for stope overlying strata.J Shandong Inst Min Technol1979;1:12–25.
[5]Song ZQ.Rules for the stope bearing pressure and its application.J Shandong Inst Min Technol 1982;1:1–25.
[6]Song ZQ,Jiang YJ.Basic research on the AND method of control–designing in face.J Shandong Inst Min Technol 1986;3:1–13.
[7]He MC.Present situation and prospect of rock mechanics in deep mining engineering.In:Proceedings of the 8th conference of Chinese rock mechanics and engineering.Beijing;2004.p.88–94.
[8]He MC.Conception system and evaluation indexes for deep engineering.Chin J Rock Mech Eng 2005;24(16):2854–9.
[9]He MC,Xie HQ,Peng SP,Jiang YD.Study on rock mechanics in deep mining engineering.Chin J Rock Mech Eng 2005;24(16):2803–13.
[10]Zhai XX,Zhou Y.Research on the filling body for gob-side gateway and its interaction with roof strata.Coal Mine Des 1999;8:6–8.
[11]Li HM.Roof strata control design for gob-side gateway.Chin J Rock Mech Eng2000;19(5):651–4.
[12]Liu Y,Shi PW.Existing problem on long wall remaining coal pillars support mining.J China Coal Soc 2007;32(6):565–9.
[13]Fei XM.The status-quo of support technology on gob-side entry retaining laneway and existing problem discussion.China Sci Technol Inform2008;3:31–2.
[14]He MC,Zhang GF,Qi G,Li Q,Jia QZ,Zhou J.Stability control of surrounding rocks in deep entry of Jiahe coal mine.J Min Saf Eng 2007;24(1):27–31.
[15]Zhang GF,He MC,Yu XP,Huang ZG.Research on the technique of no-pillar mining with gob-side entry formed by advanced roof caving in the protective seam in Baijiao coal mine.J Min Saf Eng 2011;28(4):511–6.
[16]Liu XQ,Zhang GF.Technology of roof cutting pressure relief gob-side entry retaining in soft fractured stratum.Coal Sci Technol 2013;S2:133–4.
[17]Song RQ,Xie JP.The application of pre-splitting roof cutting and pressure releasing technology at working face and gob-side gateway maintaining.Coal Sci Technol Mag 2012;3:52–4.
[18]Wang JG,Wang G.Discussion on gateway retained along goaf technology with roof breaking and pressure releasing.Coal Eng 2012;1:24–6.
[19]Sun XM,Liu X,Liang GF.Key parameters of gob-side entry retaining formed by roof cut and pressure releasing in thin coal seams.Chin J Rock Mech Eng2014;33(7):1449–56.
[20]He MC.Latest progress of soft rock mechanics and engineering in China.J Rock Mech Geotech Eng 2014;6(3):165–79.
[21]He MC,Gong WL,Wang J,Qi P,Tao ZG,Du S,et al.Development of a novel energy-absorbing bolt with extraordinarily large elongation and constant resistance.Int J Rock Mech Min Sci 2014;67:29–42.
[2]Qian MG.The structural model of overlying strata in the stope and its application.J China Inst Min Technol 1982;2:1–11.
[3]Qian MG,Li HC.The movement of overlying strata in longwall mining and its effect on ground pressure.J China Coal Soc 1982;2:1–12.
[4]Song ZQ.Basic rules for stope overlying strata.J Shandong Inst Min Technol1979;1:12–25.
[5]Song ZQ.Rules for the stope bearing pressure and its application.J Shandong Inst Min Technol 1982;1:1–25.
[6]Song ZQ,Jiang YJ.Basic research on the AND method of control–designing in face.J Shandong Inst Min Technol 1986;3:1–13.
[7]He MC.Present situation and prospect of rock mechanics in deep mining engineering.In:Proceedings of the 8th conference of Chinese rock mechanics and engineering.Beijing;2004.p.88–94.
[8]He MC.Conception system and evaluation indexes for deep engineering.Chin J Rock Mech Eng 2005;24(16):2854–9.
[9]He MC,Xie HQ,Peng SP,Jiang YD.Study on rock mechanics in deep mining engineering.Chin J Rock Mech Eng 2005;24(16):2803–13.
[10]Zhai XX,Zhou Y.Research on the filling body for gob-side gateway and its interaction with roof strata.Coal Mine Des 1999;8:6–8.
[11]Li HM.Roof strata control design for gob-side gateway.Chin J Rock Mech Eng2000;19(5):651–4.
[12]Liu Y,Shi PW.Existing problem on long wall remaining coal pillars support mining.J China Coal Soc 2007;32(6):565–9.
[13]Fei XM.The status-quo of support technology on gob-side entry retaining laneway and existing problem discussion.China Sci Technol Inform2008;3:31–2.
[14]He MC,Zhang GF,Qi G,Li Q,Jia QZ,Zhou J.Stability control of surrounding rocks in deep entry of Jiahe coal mine.J Min Saf Eng 2007;24(1):27–31.
[15]Zhang GF,He MC,Yu XP,Huang ZG.Research on the technique of no-pillar mining with gob-side entry formed by advanced roof caving in the protective seam in Baijiao coal mine.J Min Saf Eng 2011;28(4):511–6.
[16]Liu XQ,Zhang GF.Technology of roof cutting pressure relief gob-side entry retaining in soft fractured stratum.Coal Sci Technol 2013;S2:133–4.
[17]Song RQ,Xie JP.The application of pre-splitting roof cutting and pressure releasing technology at working face and gob-side gateway maintaining.Coal Sci Technol Mag 2012;3:52–4.
[18]Wang JG,Wang G.Discussion on gateway retained along goaf technology with roof breaking and pressure releasing.Coal Eng 2012;1:24–6.
[19]Sun XM,Liu X,Liang GF.Key parameters of gob-side entry retaining formed by roof cut and pressure releasing in thin coal seams.Chin J Rock Mech Eng2014;33(7):1449–56.
[20]He MC.Latest progress of soft rock mechanics and engineering in China.J Rock Mech Geotech Eng 2014;6(3):165–79.
[21]He MC,Gong WL,Wang J,Qi P,Tao ZG,Du S,et al.Development of a novel energy-absorbing bolt with extraordinarily large elongation and constant resistance.Int J Rock Mech Min Sci 2014;67:29–42.