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Mining subsidence forecasting by structural and geomechanical analysis
59A 941466 Statistical evaluation of hydrologic conditions in the vicinity of abandoned underground coal mines around Cannclburg, Indiana Harper, D; Olyphant, G A J Hydrol V146, N1/4, June 1993, P49-71 Statistical analysis of daily water level changes in an abandoned coal mine in Indiana has been carried out. Results indicate that changes in potentiometric level are significantly influenced by rainfall, independent of barometric pressure effects and changes in water level in an overlying aquifer. Rapid infiltration and percolation from the coalbed outcrop or rapid recharge through mining-associated pathways which bypass the lithified overburden are considered the most important factors affecting water depth.
941470 Computed subsidence of the central area of Shanghai Dassargues, A; Radu, J P; Charlier, R; Li, X L; Li, Q F lnt Assoc Engng Geol Bull N47, April 1993, P27-50 Results are shown from 3D finite element analysis using the code L A N G A M I N E of the subsidence of Shanghai. Mathematical concepts and data are described in companion papers (ibid, N47, 1993, P5-11 and PI3-26). Output is presented in the form of pore pressure contour maps at specific time steps, pore pressure-time graphs for particular nodes, and subsidencetime graphs for particular nodes. Subsidence in the future is predicted on the basis of assumed pumping and recharge and subsidence maps illustrated.
941467 Bozberg Tunnel: precision work in shield drivage and altering the support concept (In German and English) Tunnel N3, June 1993, P142.146
941471 Mining subsidence forecasting by structural and geomechanical analysis Bomboe, P; Marunteanu, C lnt Assoc Engng Geol Bull N47, April 1993, P71-77
The twin tubes of the Bozberg Tunnel on the N3 run through the Swiss Jura. The 11.87m diameter tunnels were driven using a purpose-built TBM. Part way into the drive, groundwater with unexpectedly high chloride and sulphate was encountered. This necessitated radical change in the concrete tunnel lining planned and remedial work on that already installed. Despite this hitch, advance rates of up to 16m per shift were achieved.
Mining-associated subsidence in the Petrila coalfield of Romania has been surveyed across selected topographic profiles since 1978. This comprehensive set of measurements plus good knowledge of lithologic and structural features allows medium term subsidence to be predicted with confidence. Simple numerical and analytical methods for subsidence prediction can be evaluated against the graph data available. Risks to surface structures can be assessed.
941468 Overcoming a collapse in the Karawanken Tunnel Maidl, B; Handke, D Tunn Tunnlg V25, N6, June 1993, P30-32 The Karawanken Tunnel between Italy and Slovenia was completed to schedule despite a major collapse. The 90 sq m section tunnel was driven through sedimentary rocks with shotcrete support as a crown and bench. A water-bearing fault zone was encountered in dolomitic rocks and, despite remedial dewatering, massive inflow and collapse ensued. Large, systematic drainage and injection measures were necessary to overcome the collapse. A bypass tunnel was driven from which dewatering and grouting of the collapsed zone could be carried out. Whether the failure should have been foreseen and if any preventive measures would succeed are discussed.
941472 Subsidence over producing oil and gas fields, and gas leakage to the surface Gurevich, A E; Chilingarian, G V Pet Sci Engng I/9, N3, June 1993, P239-250 Subsidence due to compaction of reservoir rocks as a result of fluid pressure reduction can enhance existing fractures and create new ones. Empirical approaches are applied to study this phenomenon because of the extreme complexity and the incompleteness of the information available. Published field observations on subsidence over producing reservoirs are reviewed. Current theories, causes and rates of subsidence, resulting stress and strain distributions, surface fissures, and the impact of subsidence on faults are examined. Future research is outlined. 63 refs
Surface subsidence, caving and rockbursts See also: 941173, 941174, 941240
941469 Simulation of ground loss in centrifuge model tests. Technical note Stone, K J L; Brown, T A Geotech Test J V16, N2, June 1993, P253-258 A simple, computer-controlled mechanical system to simulate ground loss at depth in centrifuge modelling is presented. Applications to study of mining-induced surface and subsurface subsidence and migration of boundaries into the overburden are illustrated. Other uses include investigation of local arching of groups of individual capped piles and differential soil movements adjacent to buried structures.
941473 Monitoring of the operational and geomechanical mining conditions in a Iongwall face situated in a difficult rockburst prone area - a case study Blaha, F; Zak, J Proc ISRM Symposium: Eurock'92, Chester, 14-17 September 1992 P438-444. Publ London: Thomas Tel.[brd, 1992 Rockburst is a severe problem in Czechoslovakia's OstravaKarvina coalfield, due to the great depths and changing stratigraphic conditions. The specification, application, and analysis of data from the basic operational, geomechanicak and geophysical monitoring systems used to ensure safety are described. Typical instrument layout is illustrated. Prediction of potential large rockburst events is possible, allowing remedial and preventive measures to be taken.
941470 Computed subsidence of the central area of Shanghai Dassargues, A; Radu, J P; Charlier, R; Li, X L; Li, Q F lnt Assoc Engng Geol Bull N47, April 1993, P27-50 Results are shown from 3D finite element analysis using the code L A N G A M I N E of the subsidence of Shanghai. Mathematical concepts and data are described in companion papers (ibid, N47, 1993, P5-11 and PI3-26). Output is presented in the form of pore pressure contour maps at specific time steps, pore pressure-time graphs for particular nodes, and subsidencetime graphs for particular nodes. Subsidence in the future is predicted on the basis of assumed pumping and recharge and subsidence maps illustrated.
941467 Bozberg Tunnel: precision work in shield drivage and altering the support concept (In German and English) Tunnel N3, June 1993, P142.146
941471 Mining subsidence forecasting by structural and geomechanical analysis Bomboe, P; Marunteanu, C lnt Assoc Engng Geol Bull N47, April 1993, P71-77
The twin tubes of the Bozberg Tunnel on the N3 run through the Swiss Jura. The 11.87m diameter tunnels were driven using a purpose-built TBM. Part way into the drive, groundwater with unexpectedly high chloride and sulphate was encountered. This necessitated radical change in the concrete tunnel lining planned and remedial work on that already installed. Despite this hitch, advance rates of up to 16m per shift were achieved.
Mining-associated subsidence in the Petrila coalfield of Romania has been surveyed across selected topographic profiles since 1978. This comprehensive set of measurements plus good knowledge of lithologic and structural features allows medium term subsidence to be predicted with confidence. Simple numerical and analytical methods for subsidence prediction can be evaluated against the graph data available. Risks to surface structures can be assessed.
941468 Overcoming a collapse in the Karawanken Tunnel Maidl, B; Handke, D Tunn Tunnlg V25, N6, June 1993, P30-32 The Karawanken Tunnel between Italy and Slovenia was completed to schedule despite a major collapse. The 90 sq m section tunnel was driven through sedimentary rocks with shotcrete support as a crown and bench. A water-bearing fault zone was encountered in dolomitic rocks and, despite remedial dewatering, massive inflow and collapse ensued. Large, systematic drainage and injection measures were necessary to overcome the collapse. A bypass tunnel was driven from which dewatering and grouting of the collapsed zone could be carried out. Whether the failure should have been foreseen and if any preventive measures would succeed are discussed.
941472 Subsidence over producing oil and gas fields, and gas leakage to the surface Gurevich, A E; Chilingarian, G V Pet Sci Engng I/9, N3, June 1993, P239-250 Subsidence due to compaction of reservoir rocks as a result of fluid pressure reduction can enhance existing fractures and create new ones. Empirical approaches are applied to study this phenomenon because of the extreme complexity and the incompleteness of the information available. Published field observations on subsidence over producing reservoirs are reviewed. Current theories, causes and rates of subsidence, resulting stress and strain distributions, surface fissures, and the impact of subsidence on faults are examined. Future research is outlined. 63 refs
Surface subsidence, caving and rockbursts See also: 941173, 941174, 941240
941469 Simulation of ground loss in centrifuge model tests. Technical note Stone, K J L; Brown, T A Geotech Test J V16, N2, June 1993, P253-258 A simple, computer-controlled mechanical system to simulate ground loss at depth in centrifuge modelling is presented. Applications to study of mining-induced surface and subsurface subsidence and migration of boundaries into the overburden are illustrated. Other uses include investigation of local arching of groups of individual capped piles and differential soil movements adjacent to buried structures.
941473 Monitoring of the operational and geomechanical mining conditions in a Iongwall face situated in a difficult rockburst prone area - a case study Blaha, F; Zak, J Proc ISRM Symposium: Eurock'92, Chester, 14-17 September 1992 P438-444. Publ London: Thomas Tel.[brd, 1992 Rockburst is a severe problem in Czechoslovakia's OstravaKarvina coalfield, due to the great depths and changing stratigraphic conditions. The specification, application, and analysis of data from the basic operational, geomechanicak and geophysical monitoring systems used to ensure safety are described. Typical instrument layout is illustrated. Prediction of potential large rockburst events is possible, allowing remedial and preventive measures to be taken.