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Monitoring system for the excavation of underground openings based on microcomputers
13A
851105 Stability investigation of underground rectangular excavations in soft rock Yoshinaka, R; Kikuchi, K; Fujieda, M; Ono, U; Ohnishi, M; Ohhashi, S Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P97-104. Publ London: British Geotechnical Society, 1984 This paper describes: (1) the observed destructive deformation of the openings; (2) geotechnical features of massive rocks; and (3) a method for stability analysis and its results, in large-scale underground openings in the remains of quarries excavated in soft rocks.
851106 Hybrid computational scheme for excavation and support design in jointed rock media Lorig, L J: Brady, B G H Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P105112. Publ London." British Geotechnical Society, 1984 A computational scheme is presented that takes advantage of the different deformation modes that occur in rock surrounding an excavation. The far-field rock is modelled as a transversely isotropic continuum by a boundary element scheme, while the near-field rock is modelled as a set of discrete element blocks that are defined by joints. Various forms of rock support are represented by structural elements. Application of the scheme is demonstrated by initial studies of circular excavations in regularly jointed rock masses. Auth.
851107 Static relaxation method for the analysis of excavations in discontinuous rock Stewart, I J" Brown. E T Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P149155. Publ London: British Geotechnical Society, 1984 This paper describes a numerical modelling technique specifically developed to analyse the behaviour of underground excavations located in discontinuous rock. The formulation allows for unlimited translational and rotational movements within the jointed rock mass and hence portrays realistic response characteristics of the rock-structure system. Extensional, rotational and sliding deformations are all possible depending on the properties of the joints in the rock. True progressive failure is modelled, with the mode of failure being automatically selected. Examples are given of the use of the numerical model for the analysis of the hanging wall and crown spans of mining excavations in tabular orebodies. Auth.
851108 Critical aspects of mining technology in excavation of a nuclear waste repository in salt Djahanguiri. F Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P327336. Publ London: British Geotechnical Society, 1984 Critical aspects of mining technology in the excavation of salt caverns for nuclear waste disposal are discussed. These include: repository design, excavation techniques and equipment, smooth wall blasting, possible modes of instability in the salt, gas outbursts, ground control, backfilling materials and techniques, and sealing.
RMMS
22 I
E
851109 Ground and lining behaviour of shallow underground rock chambers for the Washington D.C. subway Van Sint Jan, M L; Cording, E J Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P415422. Publ London: British Geotechnical Society, 1984 The site conditions and the performance of nine shallow station chambers excavated in rock were investigated and evaluated. Rock in many of the chambers was very blocky and seamy and contained steeply dipping shear zones striking within 5 to 15 deg to the longitudinal axis of the stations. Rock loads of 200 to 285kPa and lining displacements of 5.0 to 6.6mm were obtained in the chambers in the more heavily sheared ground; larger displacements (25 to 75mm) were obtained when the installation of the full lining was delayed. Rock chambers in better quality rock had loads smaller than 1.0kPa and 2.5mm of movement. Lining moments and thrusts were approximately 1/6 the ultimate capacity of the linings as built. Auth.
851110 Back analysis of two large-span underground complexes for mining and civil engineering Sarkka, P; Halonen, O; Polla, J Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P423430. Publ London: British Geotechnical Society, 1984 Two case histories of the planning, construction and performance of 2 projects in Finland are presented: the Luikonlahti Mine with a stoping area located above a major fault; and an air raid shelter complex in Turku. Actual stoping results are compared with predicted results.
851111 Monitoring system for the excavation of underground openings based on microcomputers Sakurai, S; Shinji, M Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P471476. Publ London: British Geotechnical Society, 1984 A method of monitoring the stability of underground openings based upon indirect evaluation of strain is presented. The strain distributions around the openings are obtained by a back analysis of measured displacements using a microcomputer with graphic display.
851112 Seismic velocities and attenuation in an underground granite waste repository subjected to heating Paulsson, B N P; King, M S Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P477483. Publ London: British Geotechnical Society, 1984 The behaviour of a granitic rock mass subjected to thermal load has been studied by an acoustic cross-hole technique between four boreholes, over a period of 2 years. Velocities between boreholes were obtained from the times-of-flight of pulses of acoustic waves between transducers clamped to the borehole wall. The attenuation was obtained by a spectral ratios technique. When the heater was turned on, the velocities increased rapidly to an asymptotic value. When the heater was turned off, the velocities decreased rapidly to their original values or below. Velocities along a particular profile were found to increase linearly with the mean temperature in the profile tested. The attenuation showed little correlation with changes in temperature or the associated thermal stresses, but there was a good correlation of attenuation with water content and the related changes in pore pressure. Auth.
851105 Stability investigation of underground rectangular excavations in soft rock Yoshinaka, R; Kikuchi, K; Fujieda, M; Ono, U; Ohnishi, M; Ohhashi, S Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P97-104. Publ London: British Geotechnical Society, 1984 This paper describes: (1) the observed destructive deformation of the openings; (2) geotechnical features of massive rocks; and (3) a method for stability analysis and its results, in large-scale underground openings in the remains of quarries excavated in soft rocks.
851106 Hybrid computational scheme for excavation and support design in jointed rock media Lorig, L J: Brady, B G H Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P105112. Publ London." British Geotechnical Society, 1984 A computational scheme is presented that takes advantage of the different deformation modes that occur in rock surrounding an excavation. The far-field rock is modelled as a transversely isotropic continuum by a boundary element scheme, while the near-field rock is modelled as a set of discrete element blocks that are defined by joints. Various forms of rock support are represented by structural elements. Application of the scheme is demonstrated by initial studies of circular excavations in regularly jointed rock masses. Auth.
851107 Static relaxation method for the analysis of excavations in discontinuous rock Stewart, I J" Brown. E T Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P149155. Publ London: British Geotechnical Society, 1984 This paper describes a numerical modelling technique specifically developed to analyse the behaviour of underground excavations located in discontinuous rock. The formulation allows for unlimited translational and rotational movements within the jointed rock mass and hence portrays realistic response characteristics of the rock-structure system. Extensional, rotational and sliding deformations are all possible depending on the properties of the joints in the rock. True progressive failure is modelled, with the mode of failure being automatically selected. Examples are given of the use of the numerical model for the analysis of the hanging wall and crown spans of mining excavations in tabular orebodies. Auth.
851108 Critical aspects of mining technology in excavation of a nuclear waste repository in salt Djahanguiri. F Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P327336. Publ London: British Geotechnical Society, 1984 Critical aspects of mining technology in the excavation of salt caverns for nuclear waste disposal are discussed. These include: repository design, excavation techniques and equipment, smooth wall blasting, possible modes of instability in the salt, gas outbursts, ground control, backfilling materials and techniques, and sealing.
RMMS
22 I
E
851109 Ground and lining behaviour of shallow underground rock chambers for the Washington D.C. subway Van Sint Jan, M L; Cording, E J Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P415422. Publ London: British Geotechnical Society, 1984 The site conditions and the performance of nine shallow station chambers excavated in rock were investigated and evaluated. Rock in many of the chambers was very blocky and seamy and contained steeply dipping shear zones striking within 5 to 15 deg to the longitudinal axis of the stations. Rock loads of 200 to 285kPa and lining displacements of 5.0 to 6.6mm were obtained in the chambers in the more heavily sheared ground; larger displacements (25 to 75mm) were obtained when the installation of the full lining was delayed. Rock chambers in better quality rock had loads smaller than 1.0kPa and 2.5mm of movement. Lining moments and thrusts were approximately 1/6 the ultimate capacity of the linings as built. Auth.
851110 Back analysis of two large-span underground complexes for mining and civil engineering Sarkka, P; Halonen, O; Polla, J Proc I S R M Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P423430. Publ London: British Geotechnical Society, 1984 Two case histories of the planning, construction and performance of 2 projects in Finland are presented: the Luikonlahti Mine with a stoping area located above a major fault; and an air raid shelter complex in Turku. Actual stoping results are compared with predicted results.
851111 Monitoring system for the excavation of underground openings based on microcomputers Sakurai, S; Shinji, M Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P471476. Publ London: British Geotechnical Society, 1984 A method of monitoring the stability of underground openings based upon indirect evaluation of strain is presented. The strain distributions around the openings are obtained by a back analysis of measured displacements using a microcomputer with graphic display.
851112 Seismic velocities and attenuation in an underground granite waste repository subjected to heating Paulsson, B N P; King, M S Proc ISRM Symposium on Design and Performance of Underground Excavations, Cambridge, 3-6 Sept 1984 P477483. Publ London: British Geotechnical Society, 1984 The behaviour of a granitic rock mass subjected to thermal load has been studied by an acoustic cross-hole technique between four boreholes, over a period of 2 years. Velocities between boreholes were obtained from the times-of-flight of pulses of acoustic waves between transducers clamped to the borehole wall. The attenuation was obtained by a spectral ratios technique. When the heater was turned on, the velocities increased rapidly to an asymptotic value. When the heater was turned off, the velocities decreased rapidly to their original values or below. Velocities along a particular profile were found to increase linearly with the mean temperature in the profile tested. The attenuation showed little correlation with changes in temperature or the associated thermal stresses, but there was a good correlation of attenuation with water content and the related changes in pore pressure. Auth.