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Phenomena, prediction and control of rockbursts in China
165A
893473 Review of archival geophysics data to identify seafloor Iongwall subsidence profiles Aston, T R C; Lapierre, A; Stewart, J M Min Engr V148, N328, Jan 1989, P336-340 A long term program to monitor seafloor subsidence in the Sydney Basin, and develop effective prediction techniques and safe, site specific production guidelines is described. Geophysical data collected since 1978 were examined before an instrumental development and monitoring program was designed. Only 2 of 13 sections examined, both over double seam extraction, showed clear seafloor troughs. Depths were 25-30% greater than predicted. Potential errors and problems encountered during the analysis may account for lack of identified subsidence from single seam working, but it is thought possible to distinguish such subsidence using geophysical data.
893474 Prediction of ground movements above shallow tunnels Wong, R C K; Kaiser, P K Proc International Symposium on Prediction and Performance in Geotechnicai Engineering, Calgary, 17-19 June 1987 P329343. Publ Rotterdam: A A Balkema, 1987 A conceptual model is developed to determine the dependence between vertical settlement and tunnel support pressure. The relation is a constantly changing function reflecting behaviour from initial elastic response to the ultimate collapse state. The shape of the function depends on initial in situ stress, tunnel depth, soil properties and construction sequence. It is verified by comparisons with field results and numerical simulations, and used to evaluate conventional design methods.
893475 Phenomena, prediction and control of rockbursts in China Mei Jianyun; Lu Jiayou Proc 6th International Conference on Rock Atechanics, Montreal, 30 Aug-lO Sept 1987 V2, P1135-1140. Publ Rotterdam: A A Balkema. 1987 Rockburst in China in coal and metal mines, tunnels, and underground structures has been considered. Prediction methods to identify rockburst prone regions, core disking, classification by drilling yield testing, and acoustic emission monitoring are described. Control methods used include stress control by design or extraction measures, water jet injection, stress relief by blasting, drilling or extraction of protective seams, and remedial support.
893476 Forecasting and combating rockbursts: recent developments Petukhov, I M Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-10 Sept 1987 V2, P!207-1210. Publ Rotterdam: A A Balkema, 1987 Recent work carried out by the Working Group on Rockburst of the International Bureau for Strata Mechanics is summarised. Thrust type deformations as a cause of burst and rockburst classification are examined. Methods of forecasting rockburst prone regions and the degree and severity within a region, preventative methods, including selection of mining method, mine design, and stress relief, and protective measures are discussed.
893477 Excess Shear Stress (ESS): an engineering criterion for assessing unstable slip and associated rockburst hazards Ryder, J A Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-lO Sept 1987 V2, P1211-1215. Publ Rotterdam: A A Balkema, 1987 Seismic events in South African underground mines are strongly associated with discontinuities or abnormal tectonic stress fields. A simple model of rockburst events is developed using the concept of ESS, the net force available to power a shear type seismic event once rupture has commenced. ESS analysis, given realistic values of fault friction and stress conditions, can give reasonable assessment of the potential of rockburst hazards, and allow protective design of mining layouts and extraction sequences.
893478 Examination of fault-slip induced rockborsting at the Strathcona Mine Hart, R D; Board, M; Brady, B; O'Hearn, B; Allan, G Key Questions in Rock Mechanics: Proc 29th US Symposium, Minneapolis, 13-15 June 1988 P369-379. Publ Rotterdam: A A Balkema, 1988 Rockburst in the Sudbury, Ontario, nickel mine, where biasthole stoping is used, was found to be related to a slickensided dyke and fault structure intersecting a panel hangingwall. The problem of fault dyke slip associated with outburst was analysed using the three dimensional distinct element code, 3DEC. Mining conditions affecting fault slip were identified by comparing induced slip calculated with the model to microseismic data gathered before and after rockburst. Key factors are identified, and consequences of continued extraction examined. 893479 Preliminary studies of microseismic activity in an abandoned limestone mine Miller, A; Richards, J A; Browitt, C W A; McCann, D M Proe lnt Conference on Foundations and Tunnels, London, 2426 March 1987 V2, P50-59. Publ Edinburgh: Engineering Technics Press, 1987 Experimental work to assess the applicability of microseismic analysis to detect roof fall activity during collapse of limestone workings is presented. The initial emphasis was on the detection of failures in the rock mass prior to roof fall, but preliminary analysis and detailed structural geology showed that most boundary surfaces for roof fall were already present. The emphasis was changed to an extensive series of weight drop and induced roof fall experiments. Results presented show that the microseismic activity associated with roof collapse can be successfully monitored and interpreted. 893480 Evaluating and predicting ground settlements caused by tunnelling in London Clay O'Reilly, M P Proc Tunnelling '88, London, 18-21 April 1988 P231-241. Publ London: IMM, 1988 A load factor approach, taking into account support conditions around the tunnel face, is adopted to quantify tunnel stability, and relations between load factor and ground loss are used to give settlement prediction. Four factors are examined: bulk strength-depth relation for London Clay; tunnel face geometry; results of model testing in centrifuges; and existing relations between width of settlement trough and depth to tunnel axis. Measurements at tunnelling projects indicate the validity of this predictive method.
1989 Pergamon Press plc. Reproduction not permitted
893473 Review of archival geophysics data to identify seafloor Iongwall subsidence profiles Aston, T R C; Lapierre, A; Stewart, J M Min Engr V148, N328, Jan 1989, P336-340 A long term program to monitor seafloor subsidence in the Sydney Basin, and develop effective prediction techniques and safe, site specific production guidelines is described. Geophysical data collected since 1978 were examined before an instrumental development and monitoring program was designed. Only 2 of 13 sections examined, both over double seam extraction, showed clear seafloor troughs. Depths were 25-30% greater than predicted. Potential errors and problems encountered during the analysis may account for lack of identified subsidence from single seam working, but it is thought possible to distinguish such subsidence using geophysical data.
893474 Prediction of ground movements above shallow tunnels Wong, R C K; Kaiser, P K Proc International Symposium on Prediction and Performance in Geotechnicai Engineering, Calgary, 17-19 June 1987 P329343. Publ Rotterdam: A A Balkema, 1987 A conceptual model is developed to determine the dependence between vertical settlement and tunnel support pressure. The relation is a constantly changing function reflecting behaviour from initial elastic response to the ultimate collapse state. The shape of the function depends on initial in situ stress, tunnel depth, soil properties and construction sequence. It is verified by comparisons with field results and numerical simulations, and used to evaluate conventional design methods.
893475 Phenomena, prediction and control of rockbursts in China Mei Jianyun; Lu Jiayou Proc 6th International Conference on Rock Atechanics, Montreal, 30 Aug-lO Sept 1987 V2, P1135-1140. Publ Rotterdam: A A Balkema. 1987 Rockburst in China in coal and metal mines, tunnels, and underground structures has been considered. Prediction methods to identify rockburst prone regions, core disking, classification by drilling yield testing, and acoustic emission monitoring are described. Control methods used include stress control by design or extraction measures, water jet injection, stress relief by blasting, drilling or extraction of protective seams, and remedial support.
893476 Forecasting and combating rockbursts: recent developments Petukhov, I M Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-10 Sept 1987 V2, P!207-1210. Publ Rotterdam: A A Balkema, 1987 Recent work carried out by the Working Group on Rockburst of the International Bureau for Strata Mechanics is summarised. Thrust type deformations as a cause of burst and rockburst classification are examined. Methods of forecasting rockburst prone regions and the degree and severity within a region, preventative methods, including selection of mining method, mine design, and stress relief, and protective measures are discussed.
893477 Excess Shear Stress (ESS): an engineering criterion for assessing unstable slip and associated rockburst hazards Ryder, J A Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-lO Sept 1987 V2, P1211-1215. Publ Rotterdam: A A Balkema, 1987 Seismic events in South African underground mines are strongly associated with discontinuities or abnormal tectonic stress fields. A simple model of rockburst events is developed using the concept of ESS, the net force available to power a shear type seismic event once rupture has commenced. ESS analysis, given realistic values of fault friction and stress conditions, can give reasonable assessment of the potential of rockburst hazards, and allow protective design of mining layouts and extraction sequences.
893478 Examination of fault-slip induced rockborsting at the Strathcona Mine Hart, R D; Board, M; Brady, B; O'Hearn, B; Allan, G Key Questions in Rock Mechanics: Proc 29th US Symposium, Minneapolis, 13-15 June 1988 P369-379. Publ Rotterdam: A A Balkema, 1988 Rockburst in the Sudbury, Ontario, nickel mine, where biasthole stoping is used, was found to be related to a slickensided dyke and fault structure intersecting a panel hangingwall. The problem of fault dyke slip associated with outburst was analysed using the three dimensional distinct element code, 3DEC. Mining conditions affecting fault slip were identified by comparing induced slip calculated with the model to microseismic data gathered before and after rockburst. Key factors are identified, and consequences of continued extraction examined. 893479 Preliminary studies of microseismic activity in an abandoned limestone mine Miller, A; Richards, J A; Browitt, C W A; McCann, D M Proe lnt Conference on Foundations and Tunnels, London, 2426 March 1987 V2, P50-59. Publ Edinburgh: Engineering Technics Press, 1987 Experimental work to assess the applicability of microseismic analysis to detect roof fall activity during collapse of limestone workings is presented. The initial emphasis was on the detection of failures in the rock mass prior to roof fall, but preliminary analysis and detailed structural geology showed that most boundary surfaces for roof fall were already present. The emphasis was changed to an extensive series of weight drop and induced roof fall experiments. Results presented show that the microseismic activity associated with roof collapse can be successfully monitored and interpreted. 893480 Evaluating and predicting ground settlements caused by tunnelling in London Clay O'Reilly, M P Proc Tunnelling '88, London, 18-21 April 1988 P231-241. Publ London: IMM, 1988 A load factor approach, taking into account support conditions around the tunnel face, is adopted to quantify tunnel stability, and relations between load factor and ground loss are used to give settlement prediction. Four factors are examined: bulk strength-depth relation for London Clay; tunnel face geometry; results of model testing in centrifuges; and existing relations between width of settlement trough and depth to tunnel axis. Measurements at tunnelling projects indicate the validity of this predictive method.
1989 Pergamon Press plc. Reproduction not permitted