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Resistance of passive inclined anchors in cohesionless medium
102A 9O230O Roof bolting - a sophisticated art Scott, J J
Direct rock support methods
Coal V26. N8, Aug 1989, P59-70 Roof bolts available today are reviewed. Bolts are classified as passive or active and point anchored or full contact. Post tensioned rebars, water inflated tubes (Swellex), friction rock stabilizers (split sets), headed rebars and combination bolts (resin-mechanical) are described. The 'super bolt', of very high strength for use in difficult ground conditions where heavy loading is expected, is also presented. Anchor stability and bolt selection are discussed. Rod or cable trusses are considered as alternatives to roof bolts.
902304 Development of a late-bearing packing material into an earlybearing one by addition of setting accelerators at the Haas Aden/Victoria 1/2 combined colliery (In German) Grosse, E; Tille, G; Schroer. D
Gluckauf V125, N19'20, Oct 1989, PIl98-1205 Tests demonstrated the feasibility of altering the time dependent behaviour of a packing material by use of additives in the mixing water. This allows existing face plant to be used to produce a late or early bearing material, depending on rock mechanical requirements. 902305 Re-use of roadways at Frickley Colliery Hall, A
902301 Resistance of passive inclined anchors in cohesionless medium Murray, E J; Geddes, J D
Geotechnique V39, N3, Sept 1988, P417-431 The passive resistances of strip and rectangular anchors in sand and loaded at angles between the horizontal and vertical are studied. Laboratory test results are compared with theoretical solutions based on upper and lower bound limit solutions of soil plasticity. Solutions in the latter case are not readily formulated. Upper bound solutions which take into account interface friction agree well with experimental results. Solutions also agree well with reported free surface stress characteristic and finite element solutions and experimental data of other workers.
902302 Oil-to-coal cavern conversion pins its success on rock bolts Hamrin, H Tunn Tunnlg V21. N7, July 1989, P18-21 Conversion of 30m high caverns which had s~ored crude oil for 20 years into coal bunkers required immediate roof support to ensure safe working conditions. Because of the oily conditions, shotcrete would not stick, and so water expandable (Swellex) bolts were installed from a floating working platform. Once safety was satisfied, the surface was cleaned using sand blasting, then shotcreted.
g i n Engr V149. N337, Oct 1989, P155-160 A new concept of working for retreat mining is proposed, reusing gate roads and thus removing the need to leave a support pillar between the faces, with consequent increase in extraction. Support chosen must resist the likely stress levels arising from passage of two face lines. It is proposed to use a dual adapted Markham shield with roof bolting facilities in conjuction with fibercrib and hardwood crib packing systems. Economics of such a system are compared to those of conventional practice.
Grouting See also." 902367 902306 Grouting of canaliculae in residual soils and behaviour of the foundations of Balbina dam de Mello, L G F S; Franco Filho, J M M; Alvise, C R
Proc 2nd International Conference on Geomecbanics in Tropical Soils, Singapore, 12-14 December 1988 VI, P385389. Publ Rotterdam: A A Balkema. 1988 The silty-clay residual soil foundations showed Iocalised high permeability due to tubular cavities (canaliculae). The use of grout was chosen to overcome the problem. Tube-a-manchette grouting was used, which applies pressure high enough to generate hydraulic fracturing with penetration and filling of canaliculae and voids intercepted by lenses of grout. Behaviour after dam construction and reservoir filling shows the success of the technique. 902307 Experimental research on grout type prestressed concrete lining at the pressure tunnel Zhao Chenghai; Wang Yong Nian
Shotcrete 902303 Shotcrete additives. Beefing up the mix Lock, J Tunn Tannlg V21, N7, July 1989, P57-58 Recent developments in additives have improved strength, application, uses and economics of shotcrete linings. Wet and dry systems are both considered. Accelerators, steel fibre reinforcement, silica fume (microsilica) additive, and glass or polymer fibre additions are described. A mix containing steel fibres and perlite has been developed for fireproofing polyethylene tunnel lining membranes.
Proe International Symposium Tunnelling for Water Resources and Power Projects, New Delhi, 19-23 January 1988 VI, P297-302. Publ New Delhi: Oxford and IBH Publishing Co, 1988 The use of high pressure grouting brings the tunnel lining and surrounding rock closer together, enabling them to bear any resulting pressure jointly. Experiments were undertaken at the Baishan HEP site to analyse effectiveness of the grouting. Two test tunnels were constructed. Effects of grout composition and its use under high pressure were studied,and tunnel pressurisation tests were undertaken. In the main tunnel, prestressed linings were monitored using strain, crack and pressure gauges. Results are discussed.
© 1990 Pergamon Press plc. Reproduction not permitted
Direct rock support methods
Coal V26. N8, Aug 1989, P59-70 Roof bolts available today are reviewed. Bolts are classified as passive or active and point anchored or full contact. Post tensioned rebars, water inflated tubes (Swellex), friction rock stabilizers (split sets), headed rebars and combination bolts (resin-mechanical) are described. The 'super bolt', of very high strength for use in difficult ground conditions where heavy loading is expected, is also presented. Anchor stability and bolt selection are discussed. Rod or cable trusses are considered as alternatives to roof bolts.
902304 Development of a late-bearing packing material into an earlybearing one by addition of setting accelerators at the Haas Aden/Victoria 1/2 combined colliery (In German) Grosse, E; Tille, G; Schroer. D
Gluckauf V125, N19'20, Oct 1989, PIl98-1205 Tests demonstrated the feasibility of altering the time dependent behaviour of a packing material by use of additives in the mixing water. This allows existing face plant to be used to produce a late or early bearing material, depending on rock mechanical requirements. 902305 Re-use of roadways at Frickley Colliery Hall, A
902301 Resistance of passive inclined anchors in cohesionless medium Murray, E J; Geddes, J D
Geotechnique V39, N3, Sept 1988, P417-431 The passive resistances of strip and rectangular anchors in sand and loaded at angles between the horizontal and vertical are studied. Laboratory test results are compared with theoretical solutions based on upper and lower bound limit solutions of soil plasticity. Solutions in the latter case are not readily formulated. Upper bound solutions which take into account interface friction agree well with experimental results. Solutions also agree well with reported free surface stress characteristic and finite element solutions and experimental data of other workers.
902302 Oil-to-coal cavern conversion pins its success on rock bolts Hamrin, H Tunn Tunnlg V21. N7, July 1989, P18-21 Conversion of 30m high caverns which had s~ored crude oil for 20 years into coal bunkers required immediate roof support to ensure safe working conditions. Because of the oily conditions, shotcrete would not stick, and so water expandable (Swellex) bolts were installed from a floating working platform. Once safety was satisfied, the surface was cleaned using sand blasting, then shotcreted.
g i n Engr V149. N337, Oct 1989, P155-160 A new concept of working for retreat mining is proposed, reusing gate roads and thus removing the need to leave a support pillar between the faces, with consequent increase in extraction. Support chosen must resist the likely stress levels arising from passage of two face lines. It is proposed to use a dual adapted Markham shield with roof bolting facilities in conjuction with fibercrib and hardwood crib packing systems. Economics of such a system are compared to those of conventional practice.
Grouting See also." 902367 902306 Grouting of canaliculae in residual soils and behaviour of the foundations of Balbina dam de Mello, L G F S; Franco Filho, J M M; Alvise, C R
Proc 2nd International Conference on Geomecbanics in Tropical Soils, Singapore, 12-14 December 1988 VI, P385389. Publ Rotterdam: A A Balkema. 1988 The silty-clay residual soil foundations showed Iocalised high permeability due to tubular cavities (canaliculae). The use of grout was chosen to overcome the problem. Tube-a-manchette grouting was used, which applies pressure high enough to generate hydraulic fracturing with penetration and filling of canaliculae and voids intercepted by lenses of grout. Behaviour after dam construction and reservoir filling shows the success of the technique. 902307 Experimental research on grout type prestressed concrete lining at the pressure tunnel Zhao Chenghai; Wang Yong Nian
Shotcrete 902303 Shotcrete additives. Beefing up the mix Lock, J Tunn Tannlg V21, N7, July 1989, P57-58 Recent developments in additives have improved strength, application, uses and economics of shotcrete linings. Wet and dry systems are both considered. Accelerators, steel fibre reinforcement, silica fume (microsilica) additive, and glass or polymer fibre additions are described. A mix containing steel fibres and perlite has been developed for fireproofing polyethylene tunnel lining membranes.
Proe International Symposium Tunnelling for Water Resources and Power Projects, New Delhi, 19-23 January 1988 VI, P297-302. Publ New Delhi: Oxford and IBH Publishing Co, 1988 The use of high pressure grouting brings the tunnel lining and surrounding rock closer together, enabling them to bear any resulting pressure jointly. Experiments were undertaken at the Baishan HEP site to analyse effectiveness of the grouting. Two test tunnels were constructed. Effects of grout composition and its use under high pressure were studied,and tunnel pressurisation tests were undertaken. In the main tunnel, prestressed linings were monitored using strain, crack and pressure gauges. Results are discussed.
© 1990 Pergamon Press plc. Reproduction not permitted