Analysis of gateroad stability at two longwall mines based on field monitoring results and numerical model analysis
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摘要
Coal mine longwall gateroads are subject to changing loading conditions induced by the advancing longwall face. The ground response and support requirements are closely related to the magnitude and orientation of the stress changes, as well as the local geology. This paper presents the monitoring results of gateroad response and support performance at two longwall mines at a 180-m and 600-m depth of cover.At the first mine, a three-entry gateroad layout was used. The second mine used a four-entry, yieldabutment-yield gateroad pillar system. Local ground deformation and support response were monitored at both sites. The monitoring period started during the development stage and continued during first panel retreat and up to second panel retreat. The two data sets were used to compare the response of the entries in two very different geotechnical settings and different gateroad layouts. The monitoring results were used to validate numerical models that simulate the loading conditions and entry response for these widely differing conditions. The validated models were used to compare the load path and ground response at the two mines. This paper demonstrates the potential for numerical models to assist mine engineers in optimizing longwall layouts and gateroad support systems.
Coal mine longwall gateroads are subject to changing loading conditions induced by the advancing longwall face. The ground response and support requirements are closely related to the magnitude and orientation of the stress changes, as well as the local geology. This paper presents the monitoring results of gateroad response and support performance at two longwall mines at a 180-m and 600-m depth of cover.At the first mine, a three-entry gateroad layout was used. The second mine used a four-entry, yieldabutment-yield gateroad pillar system. Local ground deformation and support response were monitored at both sites. The monitoring period started during the development stage and continued during first panel retreat and up to second panel retreat. The two data sets were used to compare the response of the entries in two very different geotechnical settings and different gateroad layouts. The monitoring results were used to validate numerical models that simulate the loading conditions and entry response for these widely differing conditions. The validated models were used to compare the load path and ground response at the two mines. This paper demonstrates the potential for numerical models to assist mine engineers in optimizing longwall layouts and gateroad support systems.
Coal mine longwall gateroads are subject to changing loading conditions induced by the advancing longwall face. The ground response and support requirements are closely related to the magnitude and orientation of the stress changes, as well as the local geology. This paper presents the monitoring results of gateroad response and support performance at two longwall mines at a 180-m and 600-m depth of cover.At the first mine, a three-entry gateroad layout was used. The second mine used a four-entry, yieldabutment-yield gateroad pillar system. Local ground deformation and support response were monitored at both sites. The monitoring period started during the development stage and continued during first panel retreat and up to second panel retreat. The two data sets were used to compare the response of the entries in two very different geotechnical settings and different gateroad layouts. The monitoring results were used to validate numerical models that simulate the loading conditions and entry response for these widely differing conditions. The validated models were used to compare the load path and ground response at the two mines. This paper demonstrates the potential for numerical models to assist mine engineers in optimizing longwall layouts and gateroad support systems.
引文
[1]Esterhuizen GS,Mark C,Murphy MM.Numerical model calibration for simulating coal pillars,gob and overburden response.In:Proceedings of the29th international conference on ground control in mining;2010.p.1-12.
[2]Esterhuizen GS.A stability factor for supported mine entries based on numerical model analysis.In:Proceedings of 31st international conference on ground control in mining,Morgantown,USA;2012.9 p.
[3]Esterhuizen GS,Bajpayee TS,Ellenberger JL,Murphy MM.Practical estimation of rock properties for modeling bedded coal mine strata using the coal mine roof rating.In:Proceedings of the 47th US rock mechanics/geomechanics symposium.American Rock Mechanics Association;2013.p.1634-47.
[4]Tulu IB,Esterhuizen GS,Mohamed KM,Klemetti TM.Verification of a calibrated longwall model with field measurements.In:Proceedings of the51st US rock mechanics/geomechanics symposium,San Francisco,25-28 June2017.
[5]Gearhart D,Esterhuizen GS,Tulu IB.Changes in stress and displacement caused by longwall panel retreats.In:Proceedings of the 36th international conference on ground control in mining,ICGCM.SME,Morgantown,WV;2017.p.313-20.
[6]Esterhuizen GS,Gearhart D,Tulu IB.Analysis of monitored ground support and rock mass response in a longwall tailgate entry.In:Mishra B,Lawson H,Murphy M,Perry K,editors.Proceedings of the 36th international conference on ground control in mining,Morgantown,WV;2017.p.1-11.
[7]Itasca Consulting Group.FLAC3D fast lagrangian analysis of continua in 3dimensions.Minneapolis,MN:Itasca Consulting Group;2014.
[8]Tulu IB,Esterhuizen GS,Gearhart D,Klemetti TM,Mohamed KM,Su DWH.Analysis of global and local stress changes in a longwall gateroad.In:Proceedings of the 36th international conference on ground control in mining;2017.p.100-10.
[9]Molinda GM,Mark C.Coal mine roof rating(CMRR):a practical rock mass classification for coal mines.Pittsburgh,PA:U.S.Department of the Interior,Bureau of Mines,IC 9387;1994,83p.
[10]Kaiser PK,Amann F,Steiner W.How highly stressed brittle rock failure impacts tunnel design.In:Proceedings of Eurock 2010;2010.p.27-38.
[11]Esterhuizen GS,Tulu IB,Bajpayee TS.Application of a brittle failure model to assess roof stability in coal mine entries.In:Proceedings 51st US rock mechanics/geomechanics symposium,American Rock Mechanics Association;2017,Paper No.17-444.
[12]Hoek E,Brown ET.Underground Excavations in Rock.London:Institution of Mining and Metallurgy;1980.p.525.
[13]Su DWH,Hasenfus GJ.Regional horizontal stress and its effect on longwall mining in the Northern Appalachian coal field.In:Proceedings of the 14th international conference on ground control in mining;1995.p.39-45.
[2]Esterhuizen GS.A stability factor for supported mine entries based on numerical model analysis.In:Proceedings of 31st international conference on ground control in mining,Morgantown,USA;2012.9 p.
[3]Esterhuizen GS,Bajpayee TS,Ellenberger JL,Murphy MM.Practical estimation of rock properties for modeling bedded coal mine strata using the coal mine roof rating.In:Proceedings of the 47th US rock mechanics/geomechanics symposium.American Rock Mechanics Association;2013.p.1634-47.
[4]Tulu IB,Esterhuizen GS,Mohamed KM,Klemetti TM.Verification of a calibrated longwall model with field measurements.In:Proceedings of the51st US rock mechanics/geomechanics symposium,San Francisco,25-28 June2017.
[5]Gearhart D,Esterhuizen GS,Tulu IB.Changes in stress and displacement caused by longwall panel retreats.In:Proceedings of the 36th international conference on ground control in mining,ICGCM.SME,Morgantown,WV;2017.p.313-20.
[6]Esterhuizen GS,Gearhart D,Tulu IB.Analysis of monitored ground support and rock mass response in a longwall tailgate entry.In:Mishra B,Lawson H,Murphy M,Perry K,editors.Proceedings of the 36th international conference on ground control in mining,Morgantown,WV;2017.p.1-11.
[7]Itasca Consulting Group.FLAC3D fast lagrangian analysis of continua in 3dimensions.Minneapolis,MN:Itasca Consulting Group;2014.
[8]Tulu IB,Esterhuizen GS,Gearhart D,Klemetti TM,Mohamed KM,Su DWH.Analysis of global and local stress changes in a longwall gateroad.In:Proceedings of the 36th international conference on ground control in mining;2017.p.100-10.
[9]Molinda GM,Mark C.Coal mine roof rating(CMRR):a practical rock mass classification for coal mines.Pittsburgh,PA:U.S.Department of the Interior,Bureau of Mines,IC 9387;1994,83p.
[10]Kaiser PK,Amann F,Steiner W.How highly stressed brittle rock failure impacts tunnel design.In:Proceedings of Eurock 2010;2010.p.27-38.
[11]Esterhuizen GS,Tulu IB,Bajpayee TS.Application of a brittle failure model to assess roof stability in coal mine entries.In:Proceedings 51st US rock mechanics/geomechanics symposium,American Rock Mechanics Association;2017,Paper No.17-444.
[12]Hoek E,Brown ET.Underground Excavations in Rock.London:Institution of Mining and Metallurgy;1980.p.525.
[13]Su DWH,Hasenfus GJ.Regional horizontal stress and its effect on longwall mining in the Northern Appalachian coal field.In:Proceedings of the 14th international conference on ground control in mining;1995.p.39-45.