- Email: [email protected]
Classification of New Zealand soft sedimentary rock materials
231A 924204 3-D model for dynamic problem of cracked rock mass Han, S; Kawamoto, T; Ito, T Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 1'565-571. Publ Rotterdam: A A Balkema, 1990
geomechanical properties are well characterised. Variations in seismic yield of up to 25% are obtained. Site specific analysis is necessary to lower this error level.
The problem of propagation of plane waves in a medium containing distributed discontinuities is addressed. An analytical approach, the equivalent nodal force (ENF) method, is described in which the effect of cracks is formulated as a displacement gap in a wave field. The mechanical effects of the cracks are transformed into equivalent nodal forces and conventional continuum mechanics approaches can be applied. A numerical example is presented.
Identification and classification
924205 Elastic wave propagation and hydraulic properties of cracked rocks Xu, S; King, M S; Worthington, M H Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 t'651-658. Publ Rotterdam: A A Balkema. 1990
A model is presented to describe the pressure dependence of elastic and hydraulic properties of a transversely isotropic solid containing aligned cracks, using as bases the work of Nishizawa and Dienes respectively. Effects of the geometry of the fractures on these parameters are analysed. Results are applied to predict behaviour of a slate in the laboratory and are in good agreement with measured values.
924206 Research on the correlation of the dynamic-elastic mechanical parameters of rocks with classification of rock drillability . Wang gangjia Rock Mechanics as a Multidisciplinary Science: Proc 32nd US Symposium, Norman, 10-12 July 1991 P433-439. Publ Rotterdam: A A Balkema, 1991
Drillability classification on the basis of wave velocity measurements is discussed. The theoretical relations between wave velocities and dynamic elastic properties are first briefly outlined. Measurements made on multiple samples of sedimentary, metamorphic, and igneous rocks and drilling performances in these rocks are presented, and statistical correlations examined. Relations between wave velocities and physical and lithological parameters are explored.
924207 Influence of rock properties on methods for the verification of underground nuclear explosions Dey, T N Rock Mechanics as a Muitidisciplinary Science: Proc 32nd US Symposium, Norman, 10-12 July 1991 P511-.517. Publ Rotterdam: A A Balkema, 1991 When estimating the yield of an explosion by analysing elastic waves at great distance, the effects of the response of the rock in the high stress regime on the outgoing wave should be included, together with influences on the final wave of rock responses in all regimes down to linear elastic. This is attempted for a hypothetical case with a limestone whose
See also: 924454
924208 Profile area method for statistical evaluation of rock mass quality Sen, Z Bull Assoc Engng Geol V28, N4, Nov 1991, P331-357
The profile area (PA) method for rock quality assessment is illustrated and the statistical properties of the PA method of calculating fracture spacing are examined analytically. The method takes into account not only mean intact length but standard deviation and correlation coefficient. PA values are compared to classical RQDs, Dimensionless and standard PA definitions are proposed for unique assessment of rock mass quality when intact lengths are serially correlated. These definitions also provide a basis for comparisons along scanlines of measurements within different units.
924209 Classification of rock weathering at Writing-On-Stone Provincial Park, Alberta, Canada: a study in applied geomorphology Campbell, I A Earth Surf Process Land VI6, N8, Dec 1991, P701-711 The park contains archaeologically important carvings which are deteriorating due to weathering. The rock is weakly cemented, closely jointed and fractured sandstone, characterised by spalling and cavernous or alveolar weathering. A simple classification system based on visual assessment and photo interpretation of key features was developed to identify four classes of weathering, from largely unweathered to severely weathered. Schmidt hammer tests showed large variations in rock strength and provided a numerical basis for visual assessment.
924210 Classification of New Zealand soft sedimentary rock materials Read, S A L; Millar, P Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P327-331. Publ Rotterdam: A A Baikema, 1991
Fine grained Tertiary sedimentary rocks are widespread in New Zealand. Cut slopes in these materials fail progressively, by slabbing or slaking. Tests were carded out on these sandstones, siltstones, clayey siltstones,and silty claystones to develop a suitable classification system for slopes. A system to identify susceptibility to slope degradation mechanisms has been developed using accurate field description plus bulk shrinkage index, particle size distribution, and unconfined compression strength. Effects of weathering, defects, or presence of colluvium must additionally be included in slope analysis.
© 1992 Pergamon Press Ltd. Reproduction not permitted R M M $ 29, ~--K
geomechanical properties are well characterised. Variations in seismic yield of up to 25% are obtained. Site specific analysis is necessary to lower this error level.
The problem of propagation of plane waves in a medium containing distributed discontinuities is addressed. An analytical approach, the equivalent nodal force (ENF) method, is described in which the effect of cracks is formulated as a displacement gap in a wave field. The mechanical effects of the cracks are transformed into equivalent nodal forces and conventional continuum mechanics approaches can be applied. A numerical example is presented.
Identification and classification
924205 Elastic wave propagation and hydraulic properties of cracked rocks Xu, S; King, M S; Worthington, M H Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 t'651-658. Publ Rotterdam: A A Balkema. 1990
A model is presented to describe the pressure dependence of elastic and hydraulic properties of a transversely isotropic solid containing aligned cracks, using as bases the work of Nishizawa and Dienes respectively. Effects of the geometry of the fractures on these parameters are analysed. Results are applied to predict behaviour of a slate in the laboratory and are in good agreement with measured values.
924206 Research on the correlation of the dynamic-elastic mechanical parameters of rocks with classification of rock drillability . Wang gangjia Rock Mechanics as a Multidisciplinary Science: Proc 32nd US Symposium, Norman, 10-12 July 1991 P433-439. Publ Rotterdam: A A Balkema, 1991
Drillability classification on the basis of wave velocity measurements is discussed. The theoretical relations between wave velocities and dynamic elastic properties are first briefly outlined. Measurements made on multiple samples of sedimentary, metamorphic, and igneous rocks and drilling performances in these rocks are presented, and statistical correlations examined. Relations between wave velocities and physical and lithological parameters are explored.
924207 Influence of rock properties on methods for the verification of underground nuclear explosions Dey, T N Rock Mechanics as a Muitidisciplinary Science: Proc 32nd US Symposium, Norman, 10-12 July 1991 P511-.517. Publ Rotterdam: A A Balkema, 1991 When estimating the yield of an explosion by analysing elastic waves at great distance, the effects of the response of the rock in the high stress regime on the outgoing wave should be included, together with influences on the final wave of rock responses in all regimes down to linear elastic. This is attempted for a hypothetical case with a limestone whose
See also: 924454
924208 Profile area method for statistical evaluation of rock mass quality Sen, Z Bull Assoc Engng Geol V28, N4, Nov 1991, P331-357
The profile area (PA) method for rock quality assessment is illustrated and the statistical properties of the PA method of calculating fracture spacing are examined analytically. The method takes into account not only mean intact length but standard deviation and correlation coefficient. PA values are compared to classical RQDs, Dimensionless and standard PA definitions are proposed for unique assessment of rock mass quality when intact lengths are serially correlated. These definitions also provide a basis for comparisons along scanlines of measurements within different units.
924209 Classification of rock weathering at Writing-On-Stone Provincial Park, Alberta, Canada: a study in applied geomorphology Campbell, I A Earth Surf Process Land VI6, N8, Dec 1991, P701-711 The park contains archaeologically important carvings which are deteriorating due to weathering. The rock is weakly cemented, closely jointed and fractured sandstone, characterised by spalling and cavernous or alveolar weathering. A simple classification system based on visual assessment and photo interpretation of key features was developed to identify four classes of weathering, from largely unweathered to severely weathered. Schmidt hammer tests showed large variations in rock strength and provided a numerical basis for visual assessment.
924210 Classification of New Zealand soft sedimentary rock materials Read, S A L; Millar, P Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P327-331. Publ Rotterdam: A A Baikema, 1991
Fine grained Tertiary sedimentary rocks are widespread in New Zealand. Cut slopes in these materials fail progressively, by slabbing or slaking. Tests were carded out on these sandstones, siltstones, clayey siltstones,and silty claystones to develop a suitable classification system for slopes. A system to identify susceptibility to slope degradation mechanisms has been developed using accurate field description plus bulk shrinkage index, particle size distribution, and unconfined compression strength. Effects of weathering, defects, or presence of colluvium must additionally be included in slope analysis.
© 1992 Pergamon Press Ltd. Reproduction not permitted R M M $ 29, ~--K