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Construction of the Makkah-Taif water transmission tunnel (in German)
99A and uniaxial compression, slake durability, and swelling tests carried out to determine the mechanical and time dependent properties of the rock. Structures were designed using rockstructure-time interaction analysis, which considers rock properties,lining properties, initial and redistributed stress, and the delay between excavation and lining.
882379 Elasto-plastic analysis of the stress-state around a large underground cavern Popovici, A; Tarhon, C; Suprovici, P Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 112, P1399-1410. Publ Oxford: Pergamon Press, 1986
882375 Determining pillar strength from pillar failure observation Krauland, N; Soder, P E Engng Min J V188, N8, Aug 1987, P34-40
The excavation of the cavern for the RiuI-Mare Retezat hydropower house has been modelled using nonlinear finite element analysis. Seven stages of construction were simulated. Geologic materials were described using the Drucker-Prager yield criterion and anchors and steel reinforcement by the Van Mises criterion. The analysis shows the sequence of appearance of plastic zones, and so can provide qualitative explanation of the cracks which were seen in the concrete liners during cavern construction. Useful support and reinforcement design information was provided.
Pillar failure has been divided into six stages, from no fractures to pillar disintegration, on the basis of observation. By combining observation with pillar load calculations at an advanced stage of mining, pillar strengths can be determined for mine design purposes. This method was applied to a mine in Greenland. Stress measurements confirmed calculated load levels in pillars in the various stages of failure. Convergence measurement and mapping of pillar fracturing provide a simple interactive means of assessing optimum ore extraction.
882376 Two-dimensional elastoplastic analysis of a long, cylindrical cavity under non-hydrostatic loading Detourney, E; Fairhurst, C lnt J Rock Mech g i n Sci II24, N4, Aug 1987, P197-211 A two-dimensional semi-analytic model of a long cylindrical cavity in an infinite rock mass subject to non-hydrostatic far field stress loading is presented. The rock is assumed an elastoplastic dilatant material with cohesive frictional yield strength. Boundary conditions ensure the problem is statically determinate and that a plastic zone develops completely round the cavity. Stress and displacement fields induced by excavation are determined. Important specific results are discussed. The shape of the failed region and the uneven closure are controlled by the obliquity (m), the ratio between stress deviator at infinity and the yield limit.
882377 Responses of buried cylinders to surface loads Moore, I D J Geotech Engng Div ASCE Vl13, N7, July 1987, P758-773 A semi-analytical procedure is developed to estimate the response of buried pipes or culverts to surface loads. It can be used to predict hoop force and bending moment as well as radial and circumferential deformations. One geometrical approximation is made in order to simplify the analysis. Comparison of results with those from elastic finite element solutions demonstrates the validity of this approximation. Methods of analysing tubes in trenches and embankments are considered.
882378 Elastoplastic analysis of rock masses surrounding circular opening considering strain hardening Lu Jiayou Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1329-1335. Publ Oxford: Pergamon Press, 1986 The stress in the surrounding rocks will redistribute during the excavation of an underground opening. A linear hardening material which follows the Mohr-Coulomb criterion is assumed, and the stresses, strains and the radius of the plastic zone around a circular opening are calculated. A numerical example is evaluated, and results compared to those from an analysis which does not include strain hardening.
882380 Stability analysis of underground openings in bedded rock Screenivas Rao, K Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1431-1438. Publ Oxford." Pergamon Press, 1986 Rock models of bedded sandstone, containing large rectangular openings and with different bedding angles, were tested in uniaxial compression. Stress strain behaviour and fracture patterns were recorded. To further understand the failure mechanisms, selected fracture surfaces were examined by scanning electron microscopy. Openings in beds at 45 deg to the direction of loading were least stable. Fracture initiation was by tensile stress and final failure was due to shear stress.
Underground excavation failure mechanisms 882381 Underground rock failure phenomena interpreted from elasticplastic analyses Panek, L A Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1373-1384. Publ Oxford." Pergamon Press, 1986 The often used two dimensional plane strain finite element analysis with Mohr-Coulomb failure criterion frequently does not accurately predict the rock mass behaviour in underground excavations. Elastic and elastic-plastic solutions were produced for an axisymmetric excavation in a homogeneous rock body to show the phenomenological failure process, modes of yielding, and shapes of the yielding zone. As the ratio of horizontal to vertical earth pressure increases, rock failure in triaxial extension becomes important. Design and analysis procedure should take into account the mode of rock failure at the perimeter of an excavation, based on a three dimensional stress analysis, to optimise reinforcement design.
Tunnels See also: 882114, 882142, 882237, 882270, 882275 882382 Performance of a small tunnel in clay shale Wang, R C K; Kaiser, P K Can Geotech J 1124, ?~L~,May 1987, P297-307 The tunnel was hand excavated with temporary rib and lagging support until a cast-in-place concrete lining was installed. Convergence and support performance were monitored for
© 1988 Pergamon Press pie. Reproduction not permitted
882379 Elasto-plastic analysis of the stress-state around a large underground cavern Popovici, A; Tarhon, C; Suprovici, P Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 112, P1399-1410. Publ Oxford: Pergamon Press, 1986
882375 Determining pillar strength from pillar failure observation Krauland, N; Soder, P E Engng Min J V188, N8, Aug 1987, P34-40
The excavation of the cavern for the RiuI-Mare Retezat hydropower house has been modelled using nonlinear finite element analysis. Seven stages of construction were simulated. Geologic materials were described using the Drucker-Prager yield criterion and anchors and steel reinforcement by the Van Mises criterion. The analysis shows the sequence of appearance of plastic zones, and so can provide qualitative explanation of the cracks which were seen in the concrete liners during cavern construction. Useful support and reinforcement design information was provided.
Pillar failure has been divided into six stages, from no fractures to pillar disintegration, on the basis of observation. By combining observation with pillar load calculations at an advanced stage of mining, pillar strengths can be determined for mine design purposes. This method was applied to a mine in Greenland. Stress measurements confirmed calculated load levels in pillars in the various stages of failure. Convergence measurement and mapping of pillar fracturing provide a simple interactive means of assessing optimum ore extraction.
882376 Two-dimensional elastoplastic analysis of a long, cylindrical cavity under non-hydrostatic loading Detourney, E; Fairhurst, C lnt J Rock Mech g i n Sci II24, N4, Aug 1987, P197-211 A two-dimensional semi-analytic model of a long cylindrical cavity in an infinite rock mass subject to non-hydrostatic far field stress loading is presented. The rock is assumed an elastoplastic dilatant material with cohesive frictional yield strength. Boundary conditions ensure the problem is statically determinate and that a plastic zone develops completely round the cavity. Stress and displacement fields induced by excavation are determined. Important specific results are discussed. The shape of the failed region and the uneven closure are controlled by the obliquity (m), the ratio between stress deviator at infinity and the yield limit.
882377 Responses of buried cylinders to surface loads Moore, I D J Geotech Engng Div ASCE Vl13, N7, July 1987, P758-773 A semi-analytical procedure is developed to estimate the response of buried pipes or culverts to surface loads. It can be used to predict hoop force and bending moment as well as radial and circumferential deformations. One geometrical approximation is made in order to simplify the analysis. Comparison of results with those from elastic finite element solutions demonstrates the validity of this approximation. Methods of analysing tubes in trenches and embankments are considered.
882378 Elastoplastic analysis of rock masses surrounding circular opening considering strain hardening Lu Jiayou Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1329-1335. Publ Oxford: Pergamon Press, 1986 The stress in the surrounding rocks will redistribute during the excavation of an underground opening. A linear hardening material which follows the Mohr-Coulomb criterion is assumed, and the stresses, strains and the radius of the plastic zone around a circular opening are calculated. A numerical example is evaluated, and results compared to those from an analysis which does not include strain hardening.
882380 Stability analysis of underground openings in bedded rock Screenivas Rao, K Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1431-1438. Publ Oxford." Pergamon Press, 1986 Rock models of bedded sandstone, containing large rectangular openings and with different bedding angles, were tested in uniaxial compression. Stress strain behaviour and fracture patterns were recorded. To further understand the failure mechanisms, selected fracture surfaces were examined by scanning electron microscopy. Openings in beds at 45 deg to the direction of loading were least stable. Fracture initiation was by tensile stress and final failure was due to shear stress.
Underground excavation failure mechanisms 882381 Underground rock failure phenomena interpreted from elasticplastic analyses Panek, L A Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1373-1384. Publ Oxford." Pergamon Press, 1986 The often used two dimensional plane strain finite element analysis with Mohr-Coulomb failure criterion frequently does not accurately predict the rock mass behaviour in underground excavations. Elastic and elastic-plastic solutions were produced for an axisymmetric excavation in a homogeneous rock body to show the phenomenological failure process, modes of yielding, and shapes of the yielding zone. As the ratio of horizontal to vertical earth pressure increases, rock failure in triaxial extension becomes important. Design and analysis procedure should take into account the mode of rock failure at the perimeter of an excavation, based on a three dimensional stress analysis, to optimise reinforcement design.
Tunnels See also: 882114, 882142, 882237, 882270, 882275 882382 Performance of a small tunnel in clay shale Wang, R C K; Kaiser, P K Can Geotech J 1124, ?~L~,May 1987, P297-307 The tunnel was hand excavated with temporary rib and lagging support until a cast-in-place concrete lining was installed. Convergence and support performance were monitored for
© 1988 Pergamon Press pie. Reproduction not permitted