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Application and abstraction of shaft drilling technique in coal mine construction in China. Technical note
57A have been mapped. 13 boreholes with total length 2110m were drilled along the headrace and diversion tunnel routes. Permeability tests were carried out in seven boreholes. RQD was evaluated on rock cores. Except in portal areas, rock was generally fresh to slightly weathered. Tunnel support was specified according to the Q system on the basis of qualities revealed. 941451 Observation of the underground structures of Alto Lindoso hydroelectric scheme Macedo, R; Monteiro, G; Sousa, L Proc ISRM Symposium: Eurock '92, Chester, 14-17 September 1992 P420-425. Publ London: Thomas Telford, 1992
The Alto Lindoso scheme is under construction on the Lima river in northern Portugal. The prevailing geology is Precambrian micaschist with granite intrusions. The proposed layout is illustrated and geological and geotechnical characterization described. Stress measurements and discontinuity mapping plus laboratory mechanical testing have been carried out and RMR calculated to assist in design. A monitoring system has been installed and results from this are compared to predictions from 3D boundary element analysis. 941452 Experience with anchored bolts in large permanent underground excavations Aziz, Z; Campbell, D D; Levay, J Proc International Symposium on Rock Support, Sudbury, 1619 June 1992 P467-472. Publ Rotterdam: A A Balkema, 1992
Part of the La Grande Project in the James Bay region of Quebec includes two 21m high, 16m arch width, 1330m long tailrace tunnels in gneissic granite. Resin grouted bolts of 5-7m length installed to a 2m grid were used as support. Considerable problems were encountered: inconsistent and deficient performance and installation difficulty at low temperature and under conditions of moderate inflow, and failure due to blasting effects, even at considerable distances from the blast. Quality control was difficult. It is recommended that long resingrouted bolts should not be used for permanent support in large underground structures, although short (It 3m) bolts can be used as primary support.
941454 Application and abstraction of shaft drilling technique in coal mine construction in China. Technical note Gu, D; Lin, B Min Engng V45, N8, Aug 1993, P1084-1086
An overview of the application of shaft drilling in coal mine development in China and its advantages is presented. The technical background, bit design, lining structures, and areas of future development in design of high capacity drill rigs, improved cutter life, and directional control are described.
General underground storage 941455 Protecting Stockholm's archipelago Darling, P Tunn Tunnlg V25, N6, June 1993, P19-21
In order to meet environmental regulations, it is necessary to extend the wastewater treatment plant serving Stockholm. The plant is in an underground cavern in massive granitic gneiss with no major discontinuities. Expansion is by deepening rather than lateral spreading and construction of new tanks is by drill and blast. Details are given of the drill rigs used and reasons for their selection and the different blast techniques adopted. Lining of the bottom of the tanks only was necessary, due to the excellent quality of the rock.
941456 Gas cavern excavation in South Korea Darling, P Tunn Tunnlg Pacific Rim Special Issue, Summer 1993, P27-29
A major project comprising a lkm long access tunnel, a 527m long water curtain tunnel, and 4 caverns at average depth 125m is described. Drill and blast construction was selected as the rock was too hard for roadheaders and radical project redesign would be required to enable use of a TBM. The access and water curtain tunnels are approaching completion. Equipment and techniques used for excavation and support are described. The four caverns will be excavated simultaneously.
Mines See also: 941048, 941293, 941304, 941317 941453 Mine pillar design in 1993: computers have become the opiate of the mining engineers Parker, J Min Engng V45, N7, July 1993, P714-717
Although numerical techniques are widely applied to design mine pillars, it is suggested that this approach deals with conditions which do not exist in real mines and that time, effort, and money may be wasted. A number of areas are examined: rock strength and its assessment, considering end conditions in the laboratory specimen and underground; the concepts of average pillar load and critical width; stress distributions experienced underground; and failure mechanisms and conditions in the laboratory and underground. The need to use engineering judgment in addition to computer based design is emphasised.
Radioactive waste disposal See also: 941192
941457 International Stripe Project: an overview Fairhurst, C; Gera, F; Gnirk, P; Gray, M; Stillborg, B Tunalg Underground Space Teclmol I:8, N3, July 1993, P315343
The Stripa Project was set up to investigate certain aspects of the disposal of high level radioactive waste in granitic rocks. The history and organisation of the project are summarised. Particular aspects which have been addressed are site characterisation instruments and procedures, understanding of flow and transport in fractured crystalline rocks, and design of engineered barriers for waste isolation. The work concentrated on natural and engineered barriers is reviewed.
The Alto Lindoso scheme is under construction on the Lima river in northern Portugal. The prevailing geology is Precambrian micaschist with granite intrusions. The proposed layout is illustrated and geological and geotechnical characterization described. Stress measurements and discontinuity mapping plus laboratory mechanical testing have been carried out and RMR calculated to assist in design. A monitoring system has been installed and results from this are compared to predictions from 3D boundary element analysis. 941452 Experience with anchored bolts in large permanent underground excavations Aziz, Z; Campbell, D D; Levay, J Proc International Symposium on Rock Support, Sudbury, 1619 June 1992 P467-472. Publ Rotterdam: A A Balkema, 1992
Part of the La Grande Project in the James Bay region of Quebec includes two 21m high, 16m arch width, 1330m long tailrace tunnels in gneissic granite. Resin grouted bolts of 5-7m length installed to a 2m grid were used as support. Considerable problems were encountered: inconsistent and deficient performance and installation difficulty at low temperature and under conditions of moderate inflow, and failure due to blasting effects, even at considerable distances from the blast. Quality control was difficult. It is recommended that long resingrouted bolts should not be used for permanent support in large underground structures, although short (It 3m) bolts can be used as primary support.
941454 Application and abstraction of shaft drilling technique in coal mine construction in China. Technical note Gu, D; Lin, B Min Engng V45, N8, Aug 1993, P1084-1086
An overview of the application of shaft drilling in coal mine development in China and its advantages is presented. The technical background, bit design, lining structures, and areas of future development in design of high capacity drill rigs, improved cutter life, and directional control are described.
General underground storage 941455 Protecting Stockholm's archipelago Darling, P Tunn Tunnlg V25, N6, June 1993, P19-21
In order to meet environmental regulations, it is necessary to extend the wastewater treatment plant serving Stockholm. The plant is in an underground cavern in massive granitic gneiss with no major discontinuities. Expansion is by deepening rather than lateral spreading and construction of new tanks is by drill and blast. Details are given of the drill rigs used and reasons for their selection and the different blast techniques adopted. Lining of the bottom of the tanks only was necessary, due to the excellent quality of the rock.
941456 Gas cavern excavation in South Korea Darling, P Tunn Tunnlg Pacific Rim Special Issue, Summer 1993, P27-29
A major project comprising a lkm long access tunnel, a 527m long water curtain tunnel, and 4 caverns at average depth 125m is described. Drill and blast construction was selected as the rock was too hard for roadheaders and radical project redesign would be required to enable use of a TBM. The access and water curtain tunnels are approaching completion. Equipment and techniques used for excavation and support are described. The four caverns will be excavated simultaneously.
Mines See also: 941048, 941293, 941304, 941317 941453 Mine pillar design in 1993: computers have become the opiate of the mining engineers Parker, J Min Engng V45, N7, July 1993, P714-717
Although numerical techniques are widely applied to design mine pillars, it is suggested that this approach deals with conditions which do not exist in real mines and that time, effort, and money may be wasted. A number of areas are examined: rock strength and its assessment, considering end conditions in the laboratory specimen and underground; the concepts of average pillar load and critical width; stress distributions experienced underground; and failure mechanisms and conditions in the laboratory and underground. The need to use engineering judgment in addition to computer based design is emphasised.
Radioactive waste disposal See also: 941192
941457 International Stripe Project: an overview Fairhurst, C; Gera, F; Gnirk, P; Gray, M; Stillborg, B Tunalg Underground Space Teclmol I:8, N3, July 1993, P315343
The Stripa Project was set up to investigate certain aspects of the disposal of high level radioactive waste in granitic rocks. The history and organisation of the project are summarised. Particular aspects which have been addressed are site characterisation instruments and procedures, understanding of flow and transport in fractured crystalline rocks, and design of engineered barriers for waste isolation. The work concentrated on natural and engineered barriers is reviewed.