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Rockmass characterisation for hydraulic tunnels in fractured rocks, Indira Sarovar (Bodhghat) Hydroelectric Project, Madhya Pradesh, India
282A 895430 Study on unlined pressure tunnels in stratified or jointed rock masses Li Chang; Gu Zhao-Qi; Chen Min-Zhong Proc Symposium on Rock Mechanics and Power Plants, Madrid, 12-16 September 1988 Vl, P359-366. Publ Rotterdam: A A Balkema. 1988
895434 Tunnelling through squeezing ground - s o m e e x p e r i e n c e s Sudhindra, C; Sharma, V M Proc International Symposium Tunnelling for Water Resources and Power Projects, New Della', 19-23 January 1988 VI, PIOI-I05. Pubi New DelhP Oxford and IBH Publishing Co. 1988
Unlined tunnels can be excavated relatively cheaply and quickly. Boundary element analysis has been used to model fissure opening by water pressure in stratified or jointed rock masses. Tunnel layouts in jointed or stratified rocks in slopes of different angles and under different hydraulic heads have been studied, and potential hydraulic fracturing, leakage, and effects of leakage considered. The steeper the tunnel, the more serious the effects of horizontal fissures become. Design and construction guidelines are suggested.
Experience gained from 3 tunnelling projects in the Himalayas is presented. In the first 2, headrace tunnels were excavated through the same thrust zone, one using heavy support to stop deformation, whilst the other allowed deformation to occur, leading to overloosening. Deformation under controlled conditions should be used to reduce rock load. In the third case, ground squeezing and sudden water ingress occurred. Measures to overcome problems are described. The methods of Terzaghi, Bieniawski and Barton were all inadequate in load prediction.
895431 Comlx'ehensive analysis of prestressed grouted concrete lining in hydraulic pressure tunnels of water station on the successful and failing practical example Ni Guorong; Qiu Jiangun Proc Symposium on Rock Mechanics and Power Plants, Mmteid, 12-16 September 1988 Vl. P373-376. Publ Rotterdam: A A Balkema. 1988 Two case histories are compared. The Beishan tunnel in deep competent rock was constructed by smooth blasting. The lining was cast in situ, split from the rock, and a thin grout annulus installed. The Huangqin inclined shaft is in faulted rock and close to a slope. Concrete pouring technique was poor and large amounts of grout were needed. Model tests were carried out and the influence of concrete shrinkage on stress build-up examined. The need for good design and project management is emphasised. 895432 Rnckmass characterisation for hydraulic tunnels in fractured rocks, Indira Sarovar (Bodhghat) Hydroelectric Project, Madhya lh'adesh, India Ahmed, M J Proc International Symposium Tunnelling for Water Resources and Power Projects, New Delhi, 19-23 January 1988 VI, P71-76. Publ New Delhi: Oxford and IBH Publishing Co, 1988 Q and RMR methods were used during the pre-construction stage of tunnel development to assess their ability to predict rock mass behaviour. Predicted values compared favourably with actual conditions. 895433 Three-dimemional model test research for tunnel group Hun Boli; Chen Xialing Proc International Symposium Tunnelling for Water Resources and Power Projects, New DelM, 19-23 January 1988 VI, P83-87. Publ New Delhi: Oxford and IBH Publishing Co, 1988 A 3-D model test was used to study country rock stability of a tunnel group for an underground power station. The model studies the stress distribution regularity in the stress field around each cavern, the mechanism of rock failure, and safety factors, using a geomeehanical material with high density, low strength and low elastic modulus. The model is loaded in the 3 directions of principal stress. Results show that stress distribution and failure behaviour in rock surrounding the tunnel have 3-D characteristics. Results are compared with those from finite element analysis and show general agreement.
895435 Effective method for design of power tunnel Wei Mincai Proc International Symposium Tunnelling for Water Resources and Power Projects, New Delhi, 19-23 January 1988 VI, P!37-140. Publ New Delhi: Oxford and IBH Publishing Co, 1988 Design of the power tunnel for the Lubuge power station through predominantly limestone and dolomite rock is described. The stress, displacement and stability of the surrounding rock is estimated by finite element analysis, and in situ stress measured in a trial tunnel. An engineering classifica. tion of the rock mass is developed for tunnelling and reinforcement, and is used to design tunnel lining.
Mines See also: 895118, 895199, 895200, 895211 895436 Troya - Spain's newest metal mine Suttili, K R Engng Min J VlgO. N2, Feb 1989. P28-31 Troya mine is a lead-zinc orebody in limestone and marls. The limestone acts as an aquifer and was drained before mining commenced. Room and pillar mining based on equilateral triangles allows 75-86% ore recovery. Drill and blast is used except at one highly fractured section where machine excavation is possible. The limestone and marl roofs are generally competent and bolts are used effectively. 895437 Roadway drivage in destressed ground in the Warwickshire thick coal seam Weston, W; Bains, A S Min Engr V148. N330, March 1989, P413-420 The Warwickshire thick seam is deep with weak overlying strata, and so suffers from roadway deformation and floor lift. Experience at Daw Mill and Coventry collieries is presented. All roadways are supported by D shaped steel arches, and roof bolts are used in some areas as secondary support. Drivage of roadways in destressed strata above or below the goal results in much improved conditions, and is essential to maintain access and clearance to working panels.
© 1989 Pergamon Press plc. Reproduction not permitted
895434 Tunnelling through squeezing ground - s o m e e x p e r i e n c e s Sudhindra, C; Sharma, V M Proc International Symposium Tunnelling for Water Resources and Power Projects, New Della', 19-23 January 1988 VI, PIOI-I05. Pubi New DelhP Oxford and IBH Publishing Co. 1988
Unlined tunnels can be excavated relatively cheaply and quickly. Boundary element analysis has been used to model fissure opening by water pressure in stratified or jointed rock masses. Tunnel layouts in jointed or stratified rocks in slopes of different angles and under different hydraulic heads have been studied, and potential hydraulic fracturing, leakage, and effects of leakage considered. The steeper the tunnel, the more serious the effects of horizontal fissures become. Design and construction guidelines are suggested.
Experience gained from 3 tunnelling projects in the Himalayas is presented. In the first 2, headrace tunnels were excavated through the same thrust zone, one using heavy support to stop deformation, whilst the other allowed deformation to occur, leading to overloosening. Deformation under controlled conditions should be used to reduce rock load. In the third case, ground squeezing and sudden water ingress occurred. Measures to overcome problems are described. The methods of Terzaghi, Bieniawski and Barton were all inadequate in load prediction.
895431 Comlx'ehensive analysis of prestressed grouted concrete lining in hydraulic pressure tunnels of water station on the successful and failing practical example Ni Guorong; Qiu Jiangun Proc Symposium on Rock Mechanics and Power Plants, Mmteid, 12-16 September 1988 Vl. P373-376. Publ Rotterdam: A A Balkema. 1988 Two case histories are compared. The Beishan tunnel in deep competent rock was constructed by smooth blasting. The lining was cast in situ, split from the rock, and a thin grout annulus installed. The Huangqin inclined shaft is in faulted rock and close to a slope. Concrete pouring technique was poor and large amounts of grout were needed. Model tests were carried out and the influence of concrete shrinkage on stress build-up examined. The need for good design and project management is emphasised. 895432 Rnckmass characterisation for hydraulic tunnels in fractured rocks, Indira Sarovar (Bodhghat) Hydroelectric Project, Madhya lh'adesh, India Ahmed, M J Proc International Symposium Tunnelling for Water Resources and Power Projects, New Delhi, 19-23 January 1988 VI, P71-76. Publ New Delhi: Oxford and IBH Publishing Co, 1988 Q and RMR methods were used during the pre-construction stage of tunnel development to assess their ability to predict rock mass behaviour. Predicted values compared favourably with actual conditions. 895433 Three-dimemional model test research for tunnel group Hun Boli; Chen Xialing Proc International Symposium Tunnelling for Water Resources and Power Projects, New DelM, 19-23 January 1988 VI, P83-87. Publ New Delhi: Oxford and IBH Publishing Co, 1988 A 3-D model test was used to study country rock stability of a tunnel group for an underground power station. The model studies the stress distribution regularity in the stress field around each cavern, the mechanism of rock failure, and safety factors, using a geomeehanical material with high density, low strength and low elastic modulus. The model is loaded in the 3 directions of principal stress. Results show that stress distribution and failure behaviour in rock surrounding the tunnel have 3-D characteristics. Results are compared with those from finite element analysis and show general agreement.
895435 Effective method for design of power tunnel Wei Mincai Proc International Symposium Tunnelling for Water Resources and Power Projects, New Delhi, 19-23 January 1988 VI, P!37-140. Publ New Delhi: Oxford and IBH Publishing Co, 1988 Design of the power tunnel for the Lubuge power station through predominantly limestone and dolomite rock is described. The stress, displacement and stability of the surrounding rock is estimated by finite element analysis, and in situ stress measured in a trial tunnel. An engineering classifica. tion of the rock mass is developed for tunnelling and reinforcement, and is used to design tunnel lining.
Mines See also: 895118, 895199, 895200, 895211 895436 Troya - Spain's newest metal mine Suttili, K R Engng Min J VlgO. N2, Feb 1989. P28-31 Troya mine is a lead-zinc orebody in limestone and marls. The limestone acts as an aquifer and was drained before mining commenced. Room and pillar mining based on equilateral triangles allows 75-86% ore recovery. Drill and blast is used except at one highly fractured section where machine excavation is possible. The limestone and marl roofs are generally competent and bolts are used effectively. 895437 Roadway drivage in destressed ground in the Warwickshire thick coal seam Weston, W; Bains, A S Min Engr V148. N330, March 1989, P413-420 The Warwickshire thick seam is deep with weak overlying strata, and so suffers from roadway deformation and floor lift. Experience at Daw Mill and Coventry collieries is presented. All roadways are supported by D shaped steel arches, and roof bolts are used in some areas as secondary support. Drivage of roadways in destressed strata above or below the goal results in much improved conditions, and is essential to maintain access and clearance to working panels.
© 1989 Pergamon Press plc. Reproduction not permitted