- Email: [email protected]
Longwall mining in South Africa
140A
UNDERGROUND EXCAVATIONS:CONSTRUCTION
953265 An effective repair system for lining concrete or power cable tunnels J. Yahagi, Y. Tuburaya & A. Nagata, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Balkema), 1994, pp 629-634. In Japan, power cables are encased in cylindrical or boxshaped reinforced concrete tunnels with cross-sectional openings of 3 to 20 m 2. At present, the space inside these tunnels, except for passageways, is congested with cables and supporting struts. When a concrete shell deteriorates as a result of chloride contamination, these cables must be removed so that ~ work can be carried out safely and efficiently. However, transferring the cables is a difficult and arduous process, and a method that allows tunnels to be repaired without transferring cables has long been awaited. Repairing a deteriorated concrete structure mainly consists of chipping off the deteriorated part and tilling it with new material. This paper discusses research into a method of automating the tilling and finishing work. (Authors) 953266 Coming to grips with bearing failures M. G. Bennett & H. Kohler, Tunnels & Tunnelling, 26(10), 1994, pp 23-24. Discusses some of the causes and design solutions to bearing and gearing failures in tunnel boring machines. Particular design considerations for seating and lubrication systems and ring gears are outlined. (J.M.McLaughlin)
Mines 953267 Peabody ed A. P. Sanda, Coal, 99(10), 1994, pp 44-56. The Peabody Group of companies comprise the largest coal operating group in the US. It also has interests in Mexico, South America and Australia. This article is part one of two describing the companies corporate profile covering competition, mining methods, remediation and safety aspects. (S.E.Long) 953268 Longwnil mining in South Africa B. Reid, Coal, 99(10), 1994, pp 82-83. About two-thirds of South African coal production comes from 12 large mines. Of these only four companies use longwall technology as the geology does not often lend itself to this type of mining. There has also always been no shortage of cheap labour so room and pillar methods have been preferred. This survey of longwall faces shows that most of the equipment in use is relatively old technology and where increases in productivity are required, upgrades of existing equipment will be necessary to remain competitive. (S.E.Long)
Radioactive waste disposal 953269 Underground disposal of radioactive waste by United Kingdom Nirex, Ltd C. S. Mogg & B. J. Breen, Transactions - Institution of Mining & Metallurgy, Section A, 103(May-Aug), 1994, pp A97-AI03. United Kingdom Nirex, Ltd. (Nirex), is responsible for developing and managing a facility for the safe disposal at depth of intermediate-level and some low-level radioactive waste. The company is concentrating its efforts on a proposed site at Seilafieid in Cumbria. Considerable borehole investi-
gation work has been completed. Borehole studies are supplemented by seismic surveys, other geophysical sensing and geological mapping. Site characterization now needs to focus on the rock mass itself. To achieve this Nirex announced plans in 1992 to advance geological investigations by means of an underground 'Rock Characterisation Facility'. The facility would give access to depths of about 800 m below ordance datum in the strong, low-permeability basement rocks of the Borrowdale Volcanic Group. The approach to development work on repository design and Nirex's future programme are outlined. (from Authors)
Underground construction methods 953270 New tunneling technique, PASS method Y. Tsuchiya, S. Kenmochi, T. Hara & K. Nakayama, in: Tunnelling and ground conditions. Proc. congress, Cairo. 1994, ed M.E.A. Salam, (Balkema), 1994, pp 451-455. A new technique, the 'Pre Arch Shell Support Method', which involves construction of an arched pre-lining ahead of the tunnel face prior to excavation, in order to stabilize the face and restrict surface settlement to an absolute minimum in unconsolidated shallow tunnels in the city regions, has been developed. After field experimentation and testing, this method was employed on an actual city tunnel project. The results are summarized below: 1) It was possible to drive the tunnel safely since the cutting face was in a stable condition under the umbrella of the pre-lining. 2) Houses along the tunnel route were not affected by the tunnel construction. (Authors) 953271 Design improvement of reaction force in Fronte-Jncidng method K. Ikuta, S. Furuyama, I. Abe & H. Yoshida, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Baikema), 1994, pp 347-354. At railway sites, there are many kinds ofmethods to construct underpasses under busy railway lines. In the case of FronteJacking Method, which is a non open cutting method, protective work for tracks called Pipe Roof Method is generally done to keep train services safe. In this work, steel pipes (about 60 crn in diameter) were put side by side horizontally to make them into a roof or hat-like shape. This bears the overhead load and acts as lagging. After this protective work, a prestressing steel strand and Frunte-jacks were used to haul an under-pass structure constru.cted by surface work and put it in the prescribed position. This report makes clear that Pipe Roofs for reaction forces of haulage can be fully expected as tractive reaction force from the result of measurement, and can reduce the construction cost. (from Authors) 953272 Smnil-diameter automatic shield tunnel cnst-in-place lining method realizes long-distance tunnel construction - development of ACE MOLE 1200-M2 construction method Y. Kimura & T. Saito, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Balkema), 1994, pp 377-384. At NTT (Nippon Telegraph and Telephone Corporation), smaller diameter tunnels have been required since the adoption of optical fiber telecommunication cables. An automatic shield tunnel cast-in-place lining method has been developed, instead of the conventional segment assembling type, that uses high-early-strength resin mortar as its lining material and allows lining work in the presence of water. NTT has established the automatic shield tunneling system 'ACE MOLE 1200-M2 construction method' that can select free alignment according to the alignment of a road and the
UNDERGROUND EXCAVATIONS:CONSTRUCTION
953265 An effective repair system for lining concrete or power cable tunnels J. Yahagi, Y. Tuburaya & A. Nagata, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Balkema), 1994, pp 629-634. In Japan, power cables are encased in cylindrical or boxshaped reinforced concrete tunnels with cross-sectional openings of 3 to 20 m 2. At present, the space inside these tunnels, except for passageways, is congested with cables and supporting struts. When a concrete shell deteriorates as a result of chloride contamination, these cables must be removed so that ~ work can be carried out safely and efficiently. However, transferring the cables is a difficult and arduous process, and a method that allows tunnels to be repaired without transferring cables has long been awaited. Repairing a deteriorated concrete structure mainly consists of chipping off the deteriorated part and tilling it with new material. This paper discusses research into a method of automating the tilling and finishing work. (Authors) 953266 Coming to grips with bearing failures M. G. Bennett & H. Kohler, Tunnels & Tunnelling, 26(10), 1994, pp 23-24. Discusses some of the causes and design solutions to bearing and gearing failures in tunnel boring machines. Particular design considerations for seating and lubrication systems and ring gears are outlined. (J.M.McLaughlin)
Mines 953267 Peabody ed A. P. Sanda, Coal, 99(10), 1994, pp 44-56. The Peabody Group of companies comprise the largest coal operating group in the US. It also has interests in Mexico, South America and Australia. This article is part one of two describing the companies corporate profile covering competition, mining methods, remediation and safety aspects. (S.E.Long) 953268 Longwnil mining in South Africa B. Reid, Coal, 99(10), 1994, pp 82-83. About two-thirds of South African coal production comes from 12 large mines. Of these only four companies use longwall technology as the geology does not often lend itself to this type of mining. There has also always been no shortage of cheap labour so room and pillar methods have been preferred. This survey of longwall faces shows that most of the equipment in use is relatively old technology and where increases in productivity are required, upgrades of existing equipment will be necessary to remain competitive. (S.E.Long)
Radioactive waste disposal 953269 Underground disposal of radioactive waste by United Kingdom Nirex, Ltd C. S. Mogg & B. J. Breen, Transactions - Institution of Mining & Metallurgy, Section A, 103(May-Aug), 1994, pp A97-AI03. United Kingdom Nirex, Ltd. (Nirex), is responsible for developing and managing a facility for the safe disposal at depth of intermediate-level and some low-level radioactive waste. The company is concentrating its efforts on a proposed site at Seilafieid in Cumbria. Considerable borehole investi-
gation work has been completed. Borehole studies are supplemented by seismic surveys, other geophysical sensing and geological mapping. Site characterization now needs to focus on the rock mass itself. To achieve this Nirex announced plans in 1992 to advance geological investigations by means of an underground 'Rock Characterisation Facility'. The facility would give access to depths of about 800 m below ordance datum in the strong, low-permeability basement rocks of the Borrowdale Volcanic Group. The approach to development work on repository design and Nirex's future programme are outlined. (from Authors)
Underground construction methods 953270 New tunneling technique, PASS method Y. Tsuchiya, S. Kenmochi, T. Hara & K. Nakayama, in: Tunnelling and ground conditions. Proc. congress, Cairo. 1994, ed M.E.A. Salam, (Balkema), 1994, pp 451-455. A new technique, the 'Pre Arch Shell Support Method', which involves construction of an arched pre-lining ahead of the tunnel face prior to excavation, in order to stabilize the face and restrict surface settlement to an absolute minimum in unconsolidated shallow tunnels in the city regions, has been developed. After field experimentation and testing, this method was employed on an actual city tunnel project. The results are summarized below: 1) It was possible to drive the tunnel safely since the cutting face was in a stable condition under the umbrella of the pre-lining. 2) Houses along the tunnel route were not affected by the tunnel construction. (Authors) 953271 Design improvement of reaction force in Fronte-Jncidng method K. Ikuta, S. Furuyama, I. Abe & H. Yoshida, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Baikema), 1994, pp 347-354. At railway sites, there are many kinds ofmethods to construct underpasses under busy railway lines. In the case of FronteJacking Method, which is a non open cutting method, protective work for tracks called Pipe Roof Method is generally done to keep train services safe. In this work, steel pipes (about 60 crn in diameter) were put side by side horizontally to make them into a roof or hat-like shape. This bears the overhead load and acts as lagging. After this protective work, a prestressing steel strand and Frunte-jacks were used to haul an under-pass structure constru.cted by surface work and put it in the prescribed position. This report makes clear that Pipe Roofs for reaction forces of haulage can be fully expected as tractive reaction force from the result of measurement, and can reduce the construction cost. (from Authors) 953272 Smnil-diameter automatic shield tunnel cnst-in-place lining method realizes long-distance tunnel construction - development of ACE MOLE 1200-M2 construction method Y. Kimura & T. Saito, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Balkema), 1994, pp 377-384. At NTT (Nippon Telegraph and Telephone Corporation), smaller diameter tunnels have been required since the adoption of optical fiber telecommunication cables. An automatic shield tunnel cast-in-place lining method has been developed, instead of the conventional segment assembling type, that uses high-early-strength resin mortar as its lining material and allows lining work in the presence of water. NTT has established the automatic shield tunneling system 'ACE MOLE 1200-M2 construction method' that can select free alignment according to the alignment of a road and the