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NATM challenge at the Montemor Tunnel
326A
EXCAVATIONS:MINES & QUARRIES
967292
More private road tunnelling M. Page, Tunnels & Tunnelling, 27(12), 1995, p 21. A brief overview of tunnelling activity in France and the country’s position in the European TBM market. France and the UK share 34% of the TBM market between them. In France there is a trend towards more private funding, particularly for road tunnel schemes. More large transport tunnels are planned as road and rail links between France and neighbouring countries are improved. Several large tunnel projects are briefly reviewed. (T.M.McLaughlin) 967293 Coping with sticky ground in Lille M. Page, Tunnels & Tunnelling, 27(12), 1995, pp 26-27. This article describes tunnelling operations and equipment being used on the Lille Metro Tunnel Extension in France. Emphasis is on geology, ground conditions encountered, and excavation progress. The ground consists of layers of silt, sand and gravel which overlay sticky Louvil Clay. A Five Cail Babcock (FCB) slurry shield with air bubble control is being used. The tunnel has gradients of 7% in sections. During the first drive where the TBM had become wholly submerged in the clay, some sticking and clogging problems were experienced. For further drives, the tunnel profile was modified to allow working in 20% silt and 80% clay to minimise these problems. Compensation works were not required, and maximum settlements in the tunnel vicinity were 8 mm, and averaged 3 mm. (J.M.McLaughlin) 967294 Lyons boast France’s first BOT contract ANON, Tunnels & Tunnelling, 27(12), 1995, pp 22-23. This large tunnel project is looked at in detail. This is the first build, operate, transfer (BOT) tunnel project awarded in France. The tunnel consists of two parallel tubes each 3220 m long and 11.4 m in diameter. They will be driven by earth pressure balance machines and lined with bolted precast concrete segments. The geology, EPB machines and tunneling progress are detailed. (J.M.McLaughlin) 967295 NATM challenge at the Montemor Tunnel S. Wallis, Tunnels & TunnelZing, 27(12), 1995, pp 32-34. This article describes ground conditions and excavation of the 720 m long Montemor highway tunnel which forms part of the new toll ring road around Lisbon, Portugal. Given the complex geology and limited cover, the tunnel was to be excavated mainly by road header using NATM principles. Deformation monitoring and instrumentation is detailed. Two tunnel collapses, occurring in quick succession, were traced to a leaking pressurised water pipe. Repair works are detailed. (J.M.McLaughlin) 967296 Displacement monitoring on the Mum Metro R. Kulesza, Ching Wu, D. Koutsoftas & D. Sutter, Tunnels & Tunnelling, 28(3), 1996, pp 32-34. Muni Metro Tumback is an extension southwards of the existing MUNI light rail subway and includes an underground turnback facility to improve subway system operation. This article reviews the background behind the project and details the instrumentation used to monitor displacements. Remotely accessed electrolytic tilt meters allowed 24 hour monitoring of the vertical displacement of the tunnels. (C.Paice)
Mines and quarries 967297 Significance of selective mineral exploitation for economical and environmentally beneficial underground ore mining W. Knissel, J. Hilger & M. Fahlbusch, Mineral Resources Engineering, 4(2), 1995, PP 165-174.
By means of model calculations the significance of selective mineral exploitation to the economics of underground metal mining is discussed. An analysis of the economic impact showed that to obtain the maximum net present value, an optimum combination of mining losses and dilution is required. A higher market price results in a lowering of permissible losses. In this case, permissible values of dilution are not influenced. In metal mining operations, optimum rates of dilution are low. This emphasizes the increasing significance of mining with backfill. Backfilling contributes to the disposal of mine wastes and other industrial residues. Results of backfilling is a diminution of dumps and tailing ponds on the surface and a reduction of subsidence damages. Effects of backfilling are the reduction of dilution and the diminution of mine waste disposal on the surface. (Authors) 967298 Mine development modeling at Mina Santa Rosa in Panama M. D. Johnson, D. Bikerman & M. Russell, Mining Engineering, 48(4), 1996, pp 51-57. Mina Santa Rosa, in west central Panama, is the first largescale gold mine in Panama and will soon be the largest singlemine gold producer in central America. Economically viable reserves were calculated for the deposits by using the geologic models in ore reserve computation. Among the parameters used were faults, contacts, preferential direction of structure and rock densities. Recent remodeling was enhanced by the ability to rapidly produce vertical and horizontal drill sections in any orientation. The use of a computer-stored database will also enable future geologic evolution of the current model to be quickly incorporated into the actual operation. The definitive word in model validity is mining and mining has just begun at Santa Rosa. This article discusses the creation of a mine model. (from Authors) 967299 3-D tomographic imaging of anomalous conditions in a deep silver mine M. J. Friedel, M. J. Jackson, D. F. Scott, T. J. Williams & y2S Olson, Journal of AppIied Geophysics, 34(l), 1995, pp Mining-induced stress-field changes pose both safety and economic hazards. In an effort aimed at developing technology for mitigating such hazards, the Bureau of Mines together with Hecla Mining Company conducted an active 3D seismic tomographic investigation of anomalous rockmass conditions in a large underground, high-grade, remnant ore pillar, at the Lucky Friday mine near Mullan, ID. The resulting velocity structure appears extremely heterogeneous and well correlated with mechanical models indicating the transfer of stress in direct response to mining. Regions of anomalous ground were identified using threshold probabilities. (Authors) 967300
Computer program aids design of post-mine topography M. J. Russell, Coal International, 244(2), 1996, pp 69-70. The author demonstrates how a computer program was used to design post-mine topography at an American opencast coal mine using traditional cut/till cross-sectional analysis. (Author) 967301 Britain’s highest longwall face enters production ANON, Coal International, 244(2), 1996, pp 60,83. This feature shows how Coventry Colliery, operated by Coal Investments, Limited, has started up a 5.12 m thick longwall face, part of a multi-million pound investment package to redevelop the mine. (Author) 967302 The Harworth tower - a symbol of underground environmental changes P. Shead, Mining Technology, 78(894), 1996, pp 39-45.
EXCAVATIONS:MINES & QUARRIES
967292
More private road tunnelling M. Page, Tunnels & Tunnelling, 27(12), 1995, p 21. A brief overview of tunnelling activity in France and the country’s position in the European TBM market. France and the UK share 34% of the TBM market between them. In France there is a trend towards more private funding, particularly for road tunnel schemes. More large transport tunnels are planned as road and rail links between France and neighbouring countries are improved. Several large tunnel projects are briefly reviewed. (T.M.McLaughlin) 967293 Coping with sticky ground in Lille M. Page, Tunnels & Tunnelling, 27(12), 1995, pp 26-27. This article describes tunnelling operations and equipment being used on the Lille Metro Tunnel Extension in France. Emphasis is on geology, ground conditions encountered, and excavation progress. The ground consists of layers of silt, sand and gravel which overlay sticky Louvil Clay. A Five Cail Babcock (FCB) slurry shield with air bubble control is being used. The tunnel has gradients of 7% in sections. During the first drive where the TBM had become wholly submerged in the clay, some sticking and clogging problems were experienced. For further drives, the tunnel profile was modified to allow working in 20% silt and 80% clay to minimise these problems. Compensation works were not required, and maximum settlements in the tunnel vicinity were 8 mm, and averaged 3 mm. (J.M.McLaughlin) 967294 Lyons boast France’s first BOT contract ANON, Tunnels & Tunnelling, 27(12), 1995, pp 22-23. This large tunnel project is looked at in detail. This is the first build, operate, transfer (BOT) tunnel project awarded in France. The tunnel consists of two parallel tubes each 3220 m long and 11.4 m in diameter. They will be driven by earth pressure balance machines and lined with bolted precast concrete segments. The geology, EPB machines and tunneling progress are detailed. (J.M.McLaughlin) 967295 NATM challenge at the Montemor Tunnel S. Wallis, Tunnels & TunnelZing, 27(12), 1995, pp 32-34. This article describes ground conditions and excavation of the 720 m long Montemor highway tunnel which forms part of the new toll ring road around Lisbon, Portugal. Given the complex geology and limited cover, the tunnel was to be excavated mainly by road header using NATM principles. Deformation monitoring and instrumentation is detailed. Two tunnel collapses, occurring in quick succession, were traced to a leaking pressurised water pipe. Repair works are detailed. (J.M.McLaughlin) 967296 Displacement monitoring on the Mum Metro R. Kulesza, Ching Wu, D. Koutsoftas & D. Sutter, Tunnels & Tunnelling, 28(3), 1996, pp 32-34. Muni Metro Tumback is an extension southwards of the existing MUNI light rail subway and includes an underground turnback facility to improve subway system operation. This article reviews the background behind the project and details the instrumentation used to monitor displacements. Remotely accessed electrolytic tilt meters allowed 24 hour monitoring of the vertical displacement of the tunnels. (C.Paice)
Mines and quarries 967297 Significance of selective mineral exploitation for economical and environmentally beneficial underground ore mining W. Knissel, J. Hilger & M. Fahlbusch, Mineral Resources Engineering, 4(2), 1995, PP 165-174.
By means of model calculations the significance of selective mineral exploitation to the economics of underground metal mining is discussed. An analysis of the economic impact showed that to obtain the maximum net present value, an optimum combination of mining losses and dilution is required. A higher market price results in a lowering of permissible losses. In this case, permissible values of dilution are not influenced. In metal mining operations, optimum rates of dilution are low. This emphasizes the increasing significance of mining with backfill. Backfilling contributes to the disposal of mine wastes and other industrial residues. Results of backfilling is a diminution of dumps and tailing ponds on the surface and a reduction of subsidence damages. Effects of backfilling are the reduction of dilution and the diminution of mine waste disposal on the surface. (Authors) 967298 Mine development modeling at Mina Santa Rosa in Panama M. D. Johnson, D. Bikerman & M. Russell, Mining Engineering, 48(4), 1996, pp 51-57. Mina Santa Rosa, in west central Panama, is the first largescale gold mine in Panama and will soon be the largest singlemine gold producer in central America. Economically viable reserves were calculated for the deposits by using the geologic models in ore reserve computation. Among the parameters used were faults, contacts, preferential direction of structure and rock densities. Recent remodeling was enhanced by the ability to rapidly produce vertical and horizontal drill sections in any orientation. The use of a computer-stored database will also enable future geologic evolution of the current model to be quickly incorporated into the actual operation. The definitive word in model validity is mining and mining has just begun at Santa Rosa. This article discusses the creation of a mine model. (from Authors) 967299 3-D tomographic imaging of anomalous conditions in a deep silver mine M. J. Friedel, M. J. Jackson, D. F. Scott, T. J. Williams & y2S Olson, Journal of AppIied Geophysics, 34(l), 1995, pp Mining-induced stress-field changes pose both safety and economic hazards. In an effort aimed at developing technology for mitigating such hazards, the Bureau of Mines together with Hecla Mining Company conducted an active 3D seismic tomographic investigation of anomalous rockmass conditions in a large underground, high-grade, remnant ore pillar, at the Lucky Friday mine near Mullan, ID. The resulting velocity structure appears extremely heterogeneous and well correlated with mechanical models indicating the transfer of stress in direct response to mining. Regions of anomalous ground were identified using threshold probabilities. (Authors) 967300
Computer program aids design of post-mine topography M. J. Russell, Coal International, 244(2), 1996, pp 69-70. The author demonstrates how a computer program was used to design post-mine topography at an American opencast coal mine using traditional cut/till cross-sectional analysis. (Author) 967301 Britain’s highest longwall face enters production ANON, Coal International, 244(2), 1996, pp 60,83. This feature shows how Coventry Colliery, operated by Coal Investments, Limited, has started up a 5.12 m thick longwall face, part of a multi-million pound investment package to redevelop the mine. (Author) 967302 The Harworth tower - a symbol of underground environmental changes P. Shead, Mining Technology, 78(894), 1996, pp 39-45.