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Contrasting tunnelling techniques through Penmaenbach Headland
98A the field to be explained, and forms a basis for the interpretation of field results taking stress relaxation and redistribution into account.
892377 Passive earth pressure on axisymmetric curved structures Reddy, A S; Dutt, H H Proe Eighth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Kyoto, 20-24 July 1987 V1, P8992. Publ Japan: Japanese Society for Soil Mechanics and Foundation Engineering, 1987 Passive earth pressures on axisymmetric circular, elliptic and parabolic curved underground structures are analysed using the method of characteristics. Results show the pressures increase with increased curvature of the structure.
Underground excavation failure mechanisms 892378 Designing unlined pressure tunnels in jointed rock Lu Ming; Brown, E T lot Water Power Dam Constr V40, Nil, Not, 1988, P37-41 A survey of failure mechanisms and design criteria for unlined pressure tunnels has demonstrated the need for a more rational and comprehensive approach to design analysis. A numerical method has been developed which analyses the combined effects of discontinuities and stresses using a finite element/joint element approach. The method is applied to several simple cases showing 3 fundamental modes of failure: hydraulic jacking of joints, hydraulic shearing of joints and uplift of the ground surface.
892379 Contribution of rock mechanics to the understanding of dynamic phenomena in mines (In French) Josien, J P; Piguet, J P; Revalor, R Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-iO Sept 1987 V2, P999-1004. Publ Rotterdam." A A Balkema, 1987 Research on sudden and violent rupture of the rock mass around mine openings is presented. Dynamic phenomena observed are described. Natural and mining environmental causes of such failures and rupture mechanisms are discussed. Knowledge of and understanding of these processes is indispensible for their prediction, prevention, and remedial measures.
892380 Pillar foundation failure studies at a deep South African gold mine Hagan, T O Proc 2nd International Symposium of Rockhursts and Seismicity in Mines, Minneapolis, 8-10 June 1988 P51-61. Publ Minneapolis." University of Minnesota. 1988 Pillar foundation failure, leading to increased seismicity and rockbursting, at Western Deep Levels gold mine was investigated using macroseismic and microseismic data. drill core logs showing extent and nature of the failed zone and mapping. The data indicate a wedge-type failure mechanism where the solid pillar core punches into the failed foundation rocks causing displacements on the downdip side below the pillar.
Tunnels See also.- 892223 892381 Observations and measurements during the consofidation and repair work of a railway tunnel with a masonry lining (In Italian) Bar/a, G, Restelli, A B; Jarre, P Gallerie I/9. N27, 1988. P20-28 The monitoring system used during soil reinforcement and repair work on a tunnel lining, and the observations and measurements made are described, Flat jack tests in the lining assessed state of stress, showing deformation was enough to necessitate reinforcement. The reinforcement consisted of consolidated arches, each of 12 micropiles, injected with a cement mixture. Convergence measurements were carried out. Deformation observed after completion of repair was uniformly distributed. A cross section of the tunnel was instrumented with strain gauges at the micropiles to monitor traction due to injection pressure. The tensile force in the micropiles exhibited a peak-residual behaviour, and measured values agree well with numerical predictions. 892382 Circular tunnel with concrete lining: an analytical approximate solution (In Italian) Fanelli, M; Motta, A Gallerie V9. N27, 1988, P31-42 The case of a circular tunnel in a rock mass with a nonhydrostatic local stress state and a concrete lining of uniform thickness is considered. The lining is assumed to take the load without allowing free movement of the cavity, and an analytical solution developed using the technique of functions of complex variables, The solution is found to depend on 3 nondimensional parameters: ratio of elastic modulus of rock and concrete,ratio of the radius of excavation to lining thickness and ratio of the 2 principal stresses in the rock prior to excavation. Functions of the solution are presented in a series of diagrams. Auth. 892383 Tunnels with shotcrete flexible lining: considerations on methods of execution and on the characteristics of materials with special reference to international standards (In Italian) de Lieto, L Gallerie V9, N27. 1988, P46-56 The effects of various parameters on and development of stresses on a flexible pre-lining of shotcrete in a tunnel, directly subjected to the action of loads and effective local stresses, are considered. It is shown that elastic modulus and strength of the lining material are important, and depend on characteristics of mix and shotcreting techniques used, as well as the position of the surface on which the concrete is sprayed. A study of experimental documentation and international standards is included. 892384 Contrasting tunnelling techniques through Penmaeobach Headland Goldsby, l F Highways Transp 1/35, NIl. Nov 1988. P45-51 The tunnel through Penmaenbach headland was divided into 3 sections for construction. The west portal was driven through hard rock after removal of an extensive talus slope. The main tunnel was constructed using drill and blast with shotcrete and
~(~ 1989 Pergamon Press plc, Reproduction not permitted
99A rock bolt support. The low vibration blasting technique, necessary due to proximity to another tunnel, is described. The east portal was constructed in soft glacial deposits using a labour intensive arch support system.
892385 Guidelines for design of tunnels Duddeck, H (ed)
Tunnlg Underground Space Technol II3, N3, 1988, P237-249 The second report by the ITA Working Group on General Approaches to the Design of Tunnels. The general approach requires participation of geological, geotechnical, excavation, structural design, and legal disciplines. Elements of a structural model are outlined, and approaches based on ground conditions and tunnelling methods considered. Site investigation, monitoring, and design and safety criteria are next examined. Alternative tunnel design models, including continuum or discontinuum and bedded beam models, and empirical approaches and design guidelines are described. The information presented is gathered from many projects.
highly permeable alluvial soils. The four fullface soft ground TBMs used, which achieved impressive production rates, are described.
892389 Excavating the Lubuge power tunnel Guo Zongyan; Wan Shengpei Tunn Tunnlg V20, NIO, Oct 1988. P44-46
Excavation of a power tunnel for the Lugube HEP station through hard, generally intact rock is described. The tunnel was excavated using drill and blast, with 2 workfaces operational simultaneously. Two sets of 3-boom drill jumbos were employed, since there was a relatively narrow working face, and short cycle construction method and smooth blasting were used.
892390 Tunnelling for the new German railway system Stegemann, K D
Worm Tunnlg VI, N3, Sept 1988, P188-200 892386 Computer-aided tunneling system (CATS) aids in planning and building an urban underground reservoir project Kikutani, K: Nishio, M; Kanai, M
Tunnlg Underground Space Technol V3, N3. 1988, P263-276 The first phase of the 1880m long, 10m final diameter tunnel near Osaka, Japan. was excavated in diluvial material with high pore pressure, beneath an urban area, using an 11.22m diameter slurry shield. The CATS system was used to acquire and analyse data concerning the cutting face, slurry content and transportation, changes in tunnelling environment and tunnelling direction. It allowed continuous updating of tunnelling conditions and planning to avoid potential pitfalls. Equipment, control, backfilling of the lining, and tunnelling records are illustrated.
892387 Undersea tunnels in Norway: a state-of-the-art review Nilsen, B; Maage, M; Dahlor, T S; Hammer, T A; Smeplass, S Tunn Tunnlg V20. Ng, Sept 1988, P18-22
Ten major undersea tunnels have been constructed in Norway through a variety of rock types, from gneiss to schists and shales. Prior to tunnel construction, investigations using existing information, engineering geological mapping, acoustic profiles, seismic refraction profiles and drilling were undertaken. All the tunnels were excavated using drill and blast, with continuous probing due to uncertainty over rock conditions. Rock support was required, especially in zones of weakness where actively swelling clays occurred, and consisted of bolts, shotcrete, cast concrete,grout, insulated aluminium sheets and ethafoam. Performance of support is discussed.
Preconstruction investigations and excavation techniques for 3 tunnels in a limestone/dolomite/claystone formation are presented. Initially, core drilling, laboratory tests and seismic profiling were used to determine geology and hydrogeology of the area. Design of the tunnels was considered, leading to construction using mainly drill and blast, and shotcrete support with an inner shell of watertight concrete. Geotechnical monitoring consisted of automatic convergence measuring bolts to provide absolute deformation. Quality assurance employed is described.
892391 Realistic design of shallow tunnels in soils and rocks (In German) Laue, G; Schultz, H; Klonne, H Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-lO Sept 1987 V2, P1067-1070. Publ
Rotterdam: A A Balkema. 1987 Bochum subway tunnels have been constructed according to NATM principles for many years. The primary shotcrcte and secondary concrete lining form a compound structure. Results of long term monitoring of stresses and displacements in an instrumented cross section and additional laboratory tests are presented and used as a basis for design improvements and cost lowering.
892392 Large-scale model studies of a rockbolted tunnel Miller, W O; St John, C M Key Questions in Rock Mechanics: Proc 29th US Symposium,
Minneapolis, 13-15 June 1988 P213-236. Publ Rotterdam: A A Balkema, 1988 892388 Soft ground TBMs set a cracking pace in Caracas Wallis, S Tunn Tunnlg V20. N9. Sept 1988. P25-28
Tunnelling for the Caracas metro was problematic due to varied geological conditions, with good quality impermeable clay changing rapidly in places to wet running sands and
A large loading frame was developed to allow study of extensive plastic deformation around a tunnel before edge effects become significant. Large blocks may be subjected to true triaxial stress. Proving tests for the frame and a series of tests on model rockbolted tunnel sections were conducted, using a grout based rock simulant, to evaluate influence of rockbolt length. Results suggest less tunnel closure for shorter bolts.
1989 Pergamon Press plc. Reproduction not permitted
892377 Passive earth pressure on axisymmetric curved structures Reddy, A S; Dutt, H H Proe Eighth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Kyoto, 20-24 July 1987 V1, P8992. Publ Japan: Japanese Society for Soil Mechanics and Foundation Engineering, 1987 Passive earth pressures on axisymmetric circular, elliptic and parabolic curved underground structures are analysed using the method of characteristics. Results show the pressures increase with increased curvature of the structure.
Underground excavation failure mechanisms 892378 Designing unlined pressure tunnels in jointed rock Lu Ming; Brown, E T lot Water Power Dam Constr V40, Nil, Not, 1988, P37-41 A survey of failure mechanisms and design criteria for unlined pressure tunnels has demonstrated the need for a more rational and comprehensive approach to design analysis. A numerical method has been developed which analyses the combined effects of discontinuities and stresses using a finite element/joint element approach. The method is applied to several simple cases showing 3 fundamental modes of failure: hydraulic jacking of joints, hydraulic shearing of joints and uplift of the ground surface.
892379 Contribution of rock mechanics to the understanding of dynamic phenomena in mines (In French) Josien, J P; Piguet, J P; Revalor, R Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-iO Sept 1987 V2, P999-1004. Publ Rotterdam." A A Balkema, 1987 Research on sudden and violent rupture of the rock mass around mine openings is presented. Dynamic phenomena observed are described. Natural and mining environmental causes of such failures and rupture mechanisms are discussed. Knowledge of and understanding of these processes is indispensible for their prediction, prevention, and remedial measures.
892380 Pillar foundation failure studies at a deep South African gold mine Hagan, T O Proc 2nd International Symposium of Rockhursts and Seismicity in Mines, Minneapolis, 8-10 June 1988 P51-61. Publ Minneapolis." University of Minnesota. 1988 Pillar foundation failure, leading to increased seismicity and rockbursting, at Western Deep Levels gold mine was investigated using macroseismic and microseismic data. drill core logs showing extent and nature of the failed zone and mapping. The data indicate a wedge-type failure mechanism where the solid pillar core punches into the failed foundation rocks causing displacements on the downdip side below the pillar.
Tunnels See also.- 892223 892381 Observations and measurements during the consofidation and repair work of a railway tunnel with a masonry lining (In Italian) Bar/a, G, Restelli, A B; Jarre, P Gallerie I/9. N27, 1988. P20-28 The monitoring system used during soil reinforcement and repair work on a tunnel lining, and the observations and measurements made are described, Flat jack tests in the lining assessed state of stress, showing deformation was enough to necessitate reinforcement. The reinforcement consisted of consolidated arches, each of 12 micropiles, injected with a cement mixture. Convergence measurements were carried out. Deformation observed after completion of repair was uniformly distributed. A cross section of the tunnel was instrumented with strain gauges at the micropiles to monitor traction due to injection pressure. The tensile force in the micropiles exhibited a peak-residual behaviour, and measured values agree well with numerical predictions. 892382 Circular tunnel with concrete lining: an analytical approximate solution (In Italian) Fanelli, M; Motta, A Gallerie V9. N27, 1988, P31-42 The case of a circular tunnel in a rock mass with a nonhydrostatic local stress state and a concrete lining of uniform thickness is considered. The lining is assumed to take the load without allowing free movement of the cavity, and an analytical solution developed using the technique of functions of complex variables, The solution is found to depend on 3 nondimensional parameters: ratio of elastic modulus of rock and concrete,ratio of the radius of excavation to lining thickness and ratio of the 2 principal stresses in the rock prior to excavation. Functions of the solution are presented in a series of diagrams. Auth. 892383 Tunnels with shotcrete flexible lining: considerations on methods of execution and on the characteristics of materials with special reference to international standards (In Italian) de Lieto, L Gallerie V9, N27. 1988, P46-56 The effects of various parameters on and development of stresses on a flexible pre-lining of shotcrete in a tunnel, directly subjected to the action of loads and effective local stresses, are considered. It is shown that elastic modulus and strength of the lining material are important, and depend on characteristics of mix and shotcreting techniques used, as well as the position of the surface on which the concrete is sprayed. A study of experimental documentation and international standards is included. 892384 Contrasting tunnelling techniques through Penmaeobach Headland Goldsby, l F Highways Transp 1/35, NIl. Nov 1988. P45-51 The tunnel through Penmaenbach headland was divided into 3 sections for construction. The west portal was driven through hard rock after removal of an extensive talus slope. The main tunnel was constructed using drill and blast with shotcrete and
~(~ 1989 Pergamon Press plc, Reproduction not permitted
99A rock bolt support. The low vibration blasting technique, necessary due to proximity to another tunnel, is described. The east portal was constructed in soft glacial deposits using a labour intensive arch support system.
892385 Guidelines for design of tunnels Duddeck, H (ed)
Tunnlg Underground Space Technol II3, N3, 1988, P237-249 The second report by the ITA Working Group on General Approaches to the Design of Tunnels. The general approach requires participation of geological, geotechnical, excavation, structural design, and legal disciplines. Elements of a structural model are outlined, and approaches based on ground conditions and tunnelling methods considered. Site investigation, monitoring, and design and safety criteria are next examined. Alternative tunnel design models, including continuum or discontinuum and bedded beam models, and empirical approaches and design guidelines are described. The information presented is gathered from many projects.
highly permeable alluvial soils. The four fullface soft ground TBMs used, which achieved impressive production rates, are described.
892389 Excavating the Lubuge power tunnel Guo Zongyan; Wan Shengpei Tunn Tunnlg V20, NIO, Oct 1988. P44-46
Excavation of a power tunnel for the Lugube HEP station through hard, generally intact rock is described. The tunnel was excavated using drill and blast, with 2 workfaces operational simultaneously. Two sets of 3-boom drill jumbos were employed, since there was a relatively narrow working face, and short cycle construction method and smooth blasting were used.
892390 Tunnelling for the new German railway system Stegemann, K D
Worm Tunnlg VI, N3, Sept 1988, P188-200 892386 Computer-aided tunneling system (CATS) aids in planning and building an urban underground reservoir project Kikutani, K: Nishio, M; Kanai, M
Tunnlg Underground Space Technol V3, N3. 1988, P263-276 The first phase of the 1880m long, 10m final diameter tunnel near Osaka, Japan. was excavated in diluvial material with high pore pressure, beneath an urban area, using an 11.22m diameter slurry shield. The CATS system was used to acquire and analyse data concerning the cutting face, slurry content and transportation, changes in tunnelling environment and tunnelling direction. It allowed continuous updating of tunnelling conditions and planning to avoid potential pitfalls. Equipment, control, backfilling of the lining, and tunnelling records are illustrated.
892387 Undersea tunnels in Norway: a state-of-the-art review Nilsen, B; Maage, M; Dahlor, T S; Hammer, T A; Smeplass, S Tunn Tunnlg V20. Ng, Sept 1988, P18-22
Ten major undersea tunnels have been constructed in Norway through a variety of rock types, from gneiss to schists and shales. Prior to tunnel construction, investigations using existing information, engineering geological mapping, acoustic profiles, seismic refraction profiles and drilling were undertaken. All the tunnels were excavated using drill and blast, with continuous probing due to uncertainty over rock conditions. Rock support was required, especially in zones of weakness where actively swelling clays occurred, and consisted of bolts, shotcrete, cast concrete,grout, insulated aluminium sheets and ethafoam. Performance of support is discussed.
Preconstruction investigations and excavation techniques for 3 tunnels in a limestone/dolomite/claystone formation are presented. Initially, core drilling, laboratory tests and seismic profiling were used to determine geology and hydrogeology of the area. Design of the tunnels was considered, leading to construction using mainly drill and blast, and shotcrete support with an inner shell of watertight concrete. Geotechnical monitoring consisted of automatic convergence measuring bolts to provide absolute deformation. Quality assurance employed is described.
892391 Realistic design of shallow tunnels in soils and rocks (In German) Laue, G; Schultz, H; Klonne, H Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-lO Sept 1987 V2, P1067-1070. Publ
Rotterdam: A A Balkema. 1987 Bochum subway tunnels have been constructed according to NATM principles for many years. The primary shotcrcte and secondary concrete lining form a compound structure. Results of long term monitoring of stresses and displacements in an instrumented cross section and additional laboratory tests are presented and used as a basis for design improvements and cost lowering.
892392 Large-scale model studies of a rockbolted tunnel Miller, W O; St John, C M Key Questions in Rock Mechanics: Proc 29th US Symposium,
Minneapolis, 13-15 June 1988 P213-236. Publ Rotterdam: A A Balkema, 1988 892388 Soft ground TBMs set a cracking pace in Caracas Wallis, S Tunn Tunnlg V20. N9. Sept 1988. P25-28
Tunnelling for the Caracas metro was problematic due to varied geological conditions, with good quality impermeable clay changing rapidly in places to wet running sands and
A large loading frame was developed to allow study of extensive plastic deformation around a tunnel before edge effects become significant. Large blocks may be subjected to true triaxial stress. Proving tests for the frame and a series of tests on model rockbolted tunnel sections were conducted, using a grout based rock simulant, to evaluate influence of rockbolt length. Results suggest less tunnel closure for shorter bolts.
1989 Pergamon Press plc. Reproduction not permitted