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Scale model study on the deformation around the drift in Korean inclined coal seam
262A
Stresses around underground openings See also." 876224
computer program to do so is listed, The analysis is satist~ctory to describe a number of fieid cases. Possible improvemerits in mining techniques are proposed.
876371 Effect of dilatancy and yield criteria on displacements around tunnels Ogawa, T; Lo, K Y Can Geotech J V24, N1, Feb 1987, PlO0-113
876375 Stress distribution and rock failure around coal mine roadways Gale, W J; Blackwood, R L Int J Rock Mech :l,lin Sci ~'~4. N3. June 1987. Pl65-173
Elastoplastic analyses of stresses and displacements around circular openings have been developed, using two yield criteria, Hock and Mohr Coulomb, and a non-associated flow rule. Dilatancy and strain softening are included. Almost identical results are obtained for both criteria. Dilatancy angle is important in controlling radial displacement. Analyses of case histories in soft fractured rock and overconsolidated stiff clay give results consistent with field measurements.
MIN3D2, a boundary integral equation method program, was used for three dimensional modelling of the Stresses around rectangular mine roadways in order to study the stress distributions when the roadway intersects the in situ stress field at different angles. The effects of stress distribution on initiation of rock failure are taken into account. It is seen that in stress fields with a dominant component, driveage direction has a significant effect on type and geometry, of failure potential.
876372 Fracture mechanics and deformation processes in natural quartz: a combined Vickers indentation, SEM, and TEM study Ferguson, C C; Lloyd, G E; Knipe, R J Can d Earth Sci V24, N3, March 1987, P544-555
876376 Measurements and analyses of compaction effects on a longspan culvert Seed, R B; Ou, C Y Trans Res Rec N1089, 1986, P37-45
Mode I fracture toughness for quartz has been calculated from Vickers indentation test results, using a recently published analysis which takes into account residual stress. Results are compatible with those obtained by other methods. Scanning and transmission electron microscopy show an intensely deformed region with a very high fracture density, adjacent to indenter contact. It is suggested that the so-called plastic deformation associated with indenter deformation of quartz is controlled largely by fracturing, although some crystal-plastic accommodation process may also operate. 876373 Influence of the rheological behaviour of shotcrete on support load density (In German) Rokahr, R B; Lux, K H Felsbau VS, NI, Feb 1987, PII-18 Various numerical models for use in support design for deep tunnels in hard rock excavated using the New Austrian Tunnelling Method are critically examined and shortcomings highlighted. A modified theory is developed which allows deformation and support load to be calculated. Particular attention is paid to excavation methods and the time dependent behaviour of shotcrete, which creeps considerably in the early stages. Qualitative results and finite element analysis confirm this theory of support load distribution. 876374 Back-analysis of roof conditions in the Great Northtu~ Seam, Newcastle Coal Measures, AnstraHa, using voussoir beam theory Seedsman, R Int J g i n Geol Engng V5, N1, March 1987. P15-27 Typical roof profiles for openings in the Great Northern Seam are a thin coal layer and several metres of claystone. The anchorages of fully grouted bolts in the elaystone may fail and an extra load is imposed on the coal beam. Using voussoir beam theory, the relation between minimum coal beam thickness, elaystone thickness, and entry width can be calculated. A
Field measurements were made on a 10m span flexible metal culvert at various stages of backfill placement and compaction. Results were compared with predictions from finite element analyses both ignoring and including the modelling of compaction induced stresses and deformations. The significance of compaction effects is evident.
876377 Stability investigations of modelled rock caverns at great depth Bandis, S C; Nadim, F; Lindmann, J; Barton, N Proc International Syml~Mum on Large Rock Caverns, Helsinki, 25-28 August 1986 V2. Plt61-1170. Publ Oxford: Pergamon Press, 1986 The stability of underground caverns was examined physically, using scale models of circular openings in a three dimensional stress field, and mathematically in two dimensions, using elastoplastic closed form solutions. A comparison of results shows certain qualitative similarities.but magnitudes of measured and predicted stress differ significantly, due to the effects of the intermediate stress. It ~s suggested that reliance on the two dimensional mathematical model will lead to conservative cavern designs.
876378 Scale model study on the deformation around the drift in Korean inclined coal seam Lee, K W; Kim, M K Proc Intermltional Symposium on Complex Rock F ~ , ~ , 3-7 Not~ml~-r, 191f6 P199.206. Publ Beijing: Science Press. 1986 Many coal seams in Korea are steeply inclined and undulating. Typical strata conditions were modelled using plaster, sand, and lime. Scale model tests were used to study the changes with depth (pressure) of the closure and roof pressure on a drift in a coal seam, deformation of surrounding strata and the effect of steel arch support. Results of a stress analysis are also presented. Model and analytical predictions are compared with field measurements.
© 1987 Pergamon Journals Ltd. Reproduction not permitted
Stresses around underground openings See also." 876224
computer program to do so is listed, The analysis is satist~ctory to describe a number of fieid cases. Possible improvemerits in mining techniques are proposed.
876371 Effect of dilatancy and yield criteria on displacements around tunnels Ogawa, T; Lo, K Y Can Geotech J V24, N1, Feb 1987, PlO0-113
876375 Stress distribution and rock failure around coal mine roadways Gale, W J; Blackwood, R L Int J Rock Mech :l,lin Sci ~'~4. N3. June 1987. Pl65-173
Elastoplastic analyses of stresses and displacements around circular openings have been developed, using two yield criteria, Hock and Mohr Coulomb, and a non-associated flow rule. Dilatancy and strain softening are included. Almost identical results are obtained for both criteria. Dilatancy angle is important in controlling radial displacement. Analyses of case histories in soft fractured rock and overconsolidated stiff clay give results consistent with field measurements.
MIN3D2, a boundary integral equation method program, was used for three dimensional modelling of the Stresses around rectangular mine roadways in order to study the stress distributions when the roadway intersects the in situ stress field at different angles. The effects of stress distribution on initiation of rock failure are taken into account. It is seen that in stress fields with a dominant component, driveage direction has a significant effect on type and geometry, of failure potential.
876372 Fracture mechanics and deformation processes in natural quartz: a combined Vickers indentation, SEM, and TEM study Ferguson, C C; Lloyd, G E; Knipe, R J Can d Earth Sci V24, N3, March 1987, P544-555
876376 Measurements and analyses of compaction effects on a longspan culvert Seed, R B; Ou, C Y Trans Res Rec N1089, 1986, P37-45
Mode I fracture toughness for quartz has been calculated from Vickers indentation test results, using a recently published analysis which takes into account residual stress. Results are compatible with those obtained by other methods. Scanning and transmission electron microscopy show an intensely deformed region with a very high fracture density, adjacent to indenter contact. It is suggested that the so-called plastic deformation associated with indenter deformation of quartz is controlled largely by fracturing, although some crystal-plastic accommodation process may also operate. 876373 Influence of the rheological behaviour of shotcrete on support load density (In German) Rokahr, R B; Lux, K H Felsbau VS, NI, Feb 1987, PII-18 Various numerical models for use in support design for deep tunnels in hard rock excavated using the New Austrian Tunnelling Method are critically examined and shortcomings highlighted. A modified theory is developed which allows deformation and support load to be calculated. Particular attention is paid to excavation methods and the time dependent behaviour of shotcrete, which creeps considerably in the early stages. Qualitative results and finite element analysis confirm this theory of support load distribution. 876374 Back-analysis of roof conditions in the Great Northtu~ Seam, Newcastle Coal Measures, AnstraHa, using voussoir beam theory Seedsman, R Int J g i n Geol Engng V5, N1, March 1987. P15-27 Typical roof profiles for openings in the Great Northern Seam are a thin coal layer and several metres of claystone. The anchorages of fully grouted bolts in the elaystone may fail and an extra load is imposed on the coal beam. Using voussoir beam theory, the relation between minimum coal beam thickness, elaystone thickness, and entry width can be calculated. A
Field measurements were made on a 10m span flexible metal culvert at various stages of backfill placement and compaction. Results were compared with predictions from finite element analyses both ignoring and including the modelling of compaction induced stresses and deformations. The significance of compaction effects is evident.
876377 Stability investigations of modelled rock caverns at great depth Bandis, S C; Nadim, F; Lindmann, J; Barton, N Proc International Syml~Mum on Large Rock Caverns, Helsinki, 25-28 August 1986 V2. Plt61-1170. Publ Oxford: Pergamon Press, 1986 The stability of underground caverns was examined physically, using scale models of circular openings in a three dimensional stress field, and mathematically in two dimensions, using elastoplastic closed form solutions. A comparison of results shows certain qualitative similarities.but magnitudes of measured and predicted stress differ significantly, due to the effects of the intermediate stress. It ~s suggested that reliance on the two dimensional mathematical model will lead to conservative cavern designs.
876378 Scale model study on the deformation around the drift in Korean inclined coal seam Lee, K W; Kim, M K Proc Intermltional Symposium on Complex Rock F ~ , ~ , 3-7 Not~ml~-r, 191f6 P199.206. Publ Beijing: Science Press. 1986 Many coal seams in Korea are steeply inclined and undulating. Typical strata conditions were modelled using plaster, sand, and lime. Scale model tests were used to study the changes with depth (pressure) of the closure and roof pressure on a drift in a coal seam, deformation of surrounding strata and the effect of steel arch support. Results of a stress analysis are also presented. Model and analytical predictions are compared with field measurements.
© 1987 Pergamon Journals Ltd. Reproduction not permitted