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Elastic wave propagation in composite media
163A 933187
Effect~ of lamaut~ity ~ 1 1 0 n d i ~ rate on tl~ e'ynmic of saturated soil K azama, M; Nogami, T
Pro¢ lmternatiomd Conference oR Geoteelmical for Coastal Deeelopmem, GEO-COAST'91, Yokakama, 3-6 September 1991 1'459-462.Publ Japan: Coastal Development Institute of Technology, 1991 Extension is presented to earlier work which examined the dynamic stiffness of a layered ground or half space using thin layer elements, in which only the solid phase was considered. The saturated soil is dealt with using the generalized formulation of Biot theory. Effects of the drainage condition (permeability) and loading rate (frequency) on dynamic stiffness are evaluated. Results are compared to those for a dry soil.
under liquefaction conditions were examined. An empirical means to predict liquefaction potential using results of CFTs was also developed. 933191 Evaluation of ilquefaction susceptibility Ansal, A M
Proc Fifth IntermUiomd Conference on Soil Dymunics and F.artlulm~e F.~ff~eriq, Karlsr~e, 23-26 September 1991 P303-312. Publ Southampton: Computational Mechanics Publications, 1991
Prevost, J H; Keane, C M; Obho, N; Kayashi, K
Liquefaction susceptibility at a site in Western Anatolia with silty sand and sandy silt layers has been investigated. Peak seismic events for various return times were assessed and site response analysis carried out. A parametric study using seven semi-empirical methods based on SPT N count and grain size distribution gave large scatter in results but suggested only marginal liquefaction susceptibility. Cyclic simple shear tests support this conclusion. Pile foundations will be suitable for factory buildings at this site.
Pro¢ F~fli~laternational Conferemce on Soil Dynamics and Eart~ake Ea~Jeeriq, Karlsmke, 23-26 September 1991 P263-276. Publ Southampton: Computational Mechanics Publications, 1991
933192 Post initial liquefaction behavionr of soils Talagonov, K
933188
Validation of precednres for analysis of Ikleefaetion of sandy soil depmits
The one dimensional finite element code DYNAID is presented for seismic site response analysis. It is based on three dimensional multi-surface plasticity theory, and required material parameters can be obtained from standard laboratory tests. The procedure and its validation are illustrated. DYNAID is first used in simulation of liquefaction tests cartied out on a shaking table. Finally, it is used to simulate the Superstition Hills (California) earthquake of 1987. Computed and recorded excess pore pressures are compared and discussed. 933189 Llqwfactim of sands under u a d r a b ~ and non-uadralned conditions Chn, J
Proe F~it lmer~'ionai Coafereaee on Soil Dy~mies and Eutkqm~e F~giaeeriq, Karlsml~, 23-26 September 1991 P277-291. Publ Southampton: Computational Mechanics Publications, 1991 Liquefaction studies for granular materials under drained conditions are summarized and the influence of initial effective confining StresS on flow strength is emphasised. This results in dependence of the steady state line on both void ratio and initial effective stress. A new procedure for interpretation of undrained tests is proposed to consider these influences. A type of liquefaction which can occur under non-undrained conditions is then examined. Laboratory tests show liquefaction of dense (dilative) sands is possible under non-undrained conditions at stress states well below that for static failure, 933190 C"uaracteri~es of Bqmfaction of silt soft Fei, H C
Pro¢ F~it Immmtional Conference oR Soil Dynamics mul Eartlquake Emgbwerl~, Karlsr~e, 23-26 September 1991 P293-302. Publ Southampton: Computational Mechanics Publications, 1991 The Tangshan earthquake of July 1976 caused extensive d~mage to the city of Tianjin, primarily as a result of liquefaction of silt soils. To characterise the dynamic properties of Chinese silts, dynamic triaxial shear tests were carried out. Effects of fines content on liquefaction potential and residual strength
Proc Fiflit latermm'mud Conference on Soil Dynamics and Eartluluke EHgiaeeri~, Karlsruke, 23-26 September 1991 P313-324. Publ Southampton: Computational Mechanics Publications, 1991 Cyclic stress tests, conventionally used to study liquefaction in the laboratory, are limited to investigation only until the occurrence of initial liquefaction. Cyclic strain tests, however, allow study of both pre- and post-initial liquefaction stages. Dynamic strain tests on sands are described. On the basis of the test results, constitutive laws are developed for pore pressure buildup, shear stress decrease, and transformation of the shear stress-shear strain relation. Post-initial liquefaction behaviour is seen to be an important part of the liquefaction phenomenon. 933193 Conntermeamres agalmt the permanent ground dl~dlac~ment due to Iklmfaction Yasuda, S; Nagase, H; Kiku, H; Uchida, Y
Proc Fifth latermltiomd Comference on Soil Dynamics and Eartluptake Eqi~eri~, Karbruke, 23-26 September 1991 P341-350. Publ Southampton: Computational Mechanics Publications, 1991 Permanent ground displacements due to earthquakes in Japan can be large, up to several meters. To prevent this, countermeasures against permanent displacement due to liquefaction were studied using shaking table tests and numerical analysis. Rows of sand or steel piles, a continuous underground concrete or steel wall, or a wall of compacted materials were the chosen measures. In all cases, displacement of some area close to the countermeasure was decreased. The continuous wall was the most effective measure. Maximum effectiveness in all cases requires the countermeasure to reach through the bottom of the liquefied layer. 933194 F_J~tic wave propeption in compoeite media Lamb, W J; Zhu, X; McMechan, G A; Greenberg, M L; Castagna, J P
Geopkysies V57, N9, Sept 1992, P1155-1165 The effective medium theory of Kuster and Toksoz (1974) can be used to predict elastic response of a composite medium provided properties of each constituent are known. A
© 1993 Pergamon Press Ltd. Reproduction not permitted RMMS 30/3--L
164A solid/solid medium with randomly distributed octagonal cylindrical inclusions is considered and the importance of multiple scattering between inclusions is investigated using a finite difference numerical approach. The aim is estimation of elastic moduli and wave velocities from numerically generated observations for realistic constituent properties and study of the effect of inclusion distribution and shape. P and S wave velocities are computed for a number of inclusion filling factors.
Identification and classification See also: 933493
933195 C h ~ l c g t i o o of overlmrden properties for underground coal gasification: laboratory studies under high temperature and in situ stress conditions Wolf, K H A A; Hettema, M H H; De Pater, C J; Van Hooydonk, R Proc I S R M Symposhtm: Euroek'92, Chester, 14-17 September 1992 P99-104. Publ London: Thomas Telford, 1992 Roof rock above UCG cavities must withstand high temperatures and geomechanical and thermomechanical stresses. Samples of overburden claystone have been characterised in the laboratory before and after heating to temperatures up to 1400 deg C at 50 bar in nitrogen. Effects of the treatment on mineralogical, microstructural, and mechanical parameters are described. Classification parameters for the untreated and baked rock at ambient and high temperatures are evaluated using the schemes of Bieniawski and Hock and Brown. Cavity stand-up times are estimated.
933196 Design and support of inclined shafts through coal measures strata, the use of rock class/flcation Oldroyd, D C; Buddery, P S Proc I S R M SymposLum: Eurock'92, Cluster, 14-17 September 1992 P147-152. Publ London: Thomas Teiford, 1992
Coal mines in Natal are generally at shallow depth and reached by vertical or inclined shafts through Karoo sediments. Shaft design uses a rock classification system based on results of impact splitting, free swell, and slake durability tests. Weighted values from these tests are combined to define 5 rock classes, from very poor to very good. Support and some blasting practices are specified according to these classes. Two case examples of use of the classification are presented.
933197 Preliminary estimation of rock slope stability m ~ . rock mass ~ation systems Haines, A; Terbrugge, P J Proc 7th I S R M laterm~timud Co~,ress oR Rock Meckames, Aachen, 1620 September 1991 V2, P887-892. Publ Rotterdam: ~[ A Balkema, 1991 Classification schemes are often used at the preliminary stages of rock engineering projects. The Mining Rock Mass Rating (MRMR) scheme of Laubecher (1977) was originally developed in the mining industry to assess stability of underground excavations, but has now been extended for slope stability
applications. The use of the MRMR in design of slopes in a relatively homogeneous rock mass and in a range of heterogeneous rock units is presented. MRMR slope angles and those from rigorous analysis are compared. A chart is developed linking slope height, slope angle, and MRMR value, which is subdivided such that combinations for which rigorous analysis is desirable or essential are shown.
933198 Characterization of jointed rock masses for rock anchors Ebisu, S; Aydan, O; Komura, S; Kawamoto, T Proc Conference on Fractured and Jobtted Rock Masses, Lake Tahoe, 3-5 June 1992 P150-157. Pubi California: Lawrence Berkeley Laboratory, 1992 Anchor pullout tests and rock mass characterisation have been carried out at sandstone and granite sites. Distribution and geometry of the discontinuities were examined, elastic wave properties measured, and borehole jack tests carried out in the field. Physical and mechanical properties were measured on cores in the laboratory. RQD, maximum core length (MCL), and discontinuity number per lm length (DN) were evaluated. Correlations between the various geometrical, geophysical, mechanical, and empirical parameters have been studied, and their suitability for rock mass classification for anchor design is discussed.
933199 Statfmle tUmdmimmt ~ of joint~ reek masses Lin, Y M; Liu, X C Proe Conflreoce on Froctwted amf Yoksted Rock Masses, Lake Tahoe, 3-5 Jme 1992 P199-204. Publ California: Lawrence Berkeley Laboratory, 1992 A new classification method for rock masses is presented. This statistical method makes use of Fisher's discriminant analysis to establish a discriminant function for rock mass classification according to case history records and expert judgement. An optimal empirical formula is developed in terms of weighted values of UCS, joint spacing, and the square of the acoustic velocity ratio of rock mass and intact rock. Basic rock mass qualities can be adjusted to take into account effects of groundwater, field stresses, or geology.
933200 Charactedzafioo of weak, strafihd and clay bearing rock masses for engineering al~i~tions Ulusay, R; Ozkan, I; Unal, E Proc Comfereoce on Frocttwed amd Joimted Rock Masses, Lake Takoc, 3-5 J a e 1992 P233-240. Publ California: Lawrence Berkeley Laboratory, 1992
The Q and RMR systems widely used in mining and tunnelling will give misleading results if appl-h~d in weak, stratified, clay-bearing rock masses. A modified RMR system has been developed in Turkey for application in such rocks. Because of the difficulty in obtaining suitable cores for standard laboratory tests, point load tests are used to evaluate strength and anisotropy. A slake durability index term is included to take into account effects of groundwater. Parameters associated with condition of joints are weighted to represent the stratified nature and prvsence of clays, Applications of the original and modified RMR to design of slopes and underground excavations are shown.
© 1993 Pergamon Press Ltd. Reproduction not permitted
Effect~ of lamaut~ity ~ 1 1 0 n d i ~ rate on tl~ e'ynmic of saturated soil K azama, M; Nogami, T
Pro¢ lmternatiomd Conference oR Geoteelmical for Coastal Deeelopmem, GEO-COAST'91, Yokakama, 3-6 September 1991 1'459-462.Publ Japan: Coastal Development Institute of Technology, 1991 Extension is presented to earlier work which examined the dynamic stiffness of a layered ground or half space using thin layer elements, in which only the solid phase was considered. The saturated soil is dealt with using the generalized formulation of Biot theory. Effects of the drainage condition (permeability) and loading rate (frequency) on dynamic stiffness are evaluated. Results are compared to those for a dry soil.
under liquefaction conditions were examined. An empirical means to predict liquefaction potential using results of CFTs was also developed. 933191 Evaluation of ilquefaction susceptibility Ansal, A M
Proc Fifth IntermUiomd Conference on Soil Dymunics and F.artlulm~e F.~ff~eriq, Karlsr~e, 23-26 September 1991 P303-312. Publ Southampton: Computational Mechanics Publications, 1991
Prevost, J H; Keane, C M; Obho, N; Kayashi, K
Liquefaction susceptibility at a site in Western Anatolia with silty sand and sandy silt layers has been investigated. Peak seismic events for various return times were assessed and site response analysis carried out. A parametric study using seven semi-empirical methods based on SPT N count and grain size distribution gave large scatter in results but suggested only marginal liquefaction susceptibility. Cyclic simple shear tests support this conclusion. Pile foundations will be suitable for factory buildings at this site.
Pro¢ F~fli~laternational Conferemce on Soil Dynamics and Eart~ake Ea~Jeeriq, Karlsmke, 23-26 September 1991 P263-276. Publ Southampton: Computational Mechanics Publications, 1991
933192 Post initial liquefaction behavionr of soils Talagonov, K
933188
Validation of precednres for analysis of Ikleefaetion of sandy soil depmits
The one dimensional finite element code DYNAID is presented for seismic site response analysis. It is based on three dimensional multi-surface plasticity theory, and required material parameters can be obtained from standard laboratory tests. The procedure and its validation are illustrated. DYNAID is first used in simulation of liquefaction tests cartied out on a shaking table. Finally, it is used to simulate the Superstition Hills (California) earthquake of 1987. Computed and recorded excess pore pressures are compared and discussed. 933189 Llqwfactim of sands under u a d r a b ~ and non-uadralned conditions Chn, J
Proe F~it lmer~'ionai Coafereaee on Soil Dy~mies and Eutkqm~e F~giaeeriq, Karlsml~, 23-26 September 1991 P277-291. Publ Southampton: Computational Mechanics Publications, 1991 Liquefaction studies for granular materials under drained conditions are summarized and the influence of initial effective confining StresS on flow strength is emphasised. This results in dependence of the steady state line on both void ratio and initial effective stress. A new procedure for interpretation of undrained tests is proposed to consider these influences. A type of liquefaction which can occur under non-undrained conditions is then examined. Laboratory tests show liquefaction of dense (dilative) sands is possible under non-undrained conditions at stress states well below that for static failure, 933190 C"uaracteri~es of Bqmfaction of silt soft Fei, H C
Pro¢ F~it Immmtional Conference oR Soil Dynamics mul Eartlquake Emgbwerl~, Karlsr~e, 23-26 September 1991 P293-302. Publ Southampton: Computational Mechanics Publications, 1991 The Tangshan earthquake of July 1976 caused extensive d~mage to the city of Tianjin, primarily as a result of liquefaction of silt soils. To characterise the dynamic properties of Chinese silts, dynamic triaxial shear tests were carried out. Effects of fines content on liquefaction potential and residual strength
Proc Fiflit latermm'mud Conference on Soil Dynamics and Eartluluke EHgiaeeri~, Karlsruke, 23-26 September 1991 P313-324. Publ Southampton: Computational Mechanics Publications, 1991 Cyclic stress tests, conventionally used to study liquefaction in the laboratory, are limited to investigation only until the occurrence of initial liquefaction. Cyclic strain tests, however, allow study of both pre- and post-initial liquefaction stages. Dynamic strain tests on sands are described. On the basis of the test results, constitutive laws are developed for pore pressure buildup, shear stress decrease, and transformation of the shear stress-shear strain relation. Post-initial liquefaction behaviour is seen to be an important part of the liquefaction phenomenon. 933193 Conntermeamres agalmt the permanent ground dl~dlac~ment due to Iklmfaction Yasuda, S; Nagase, H; Kiku, H; Uchida, Y
Proc Fifth latermltiomd Comference on Soil Dynamics and Eartluptake Eqi~eri~, Karbruke, 23-26 September 1991 P341-350. Publ Southampton: Computational Mechanics Publications, 1991 Permanent ground displacements due to earthquakes in Japan can be large, up to several meters. To prevent this, countermeasures against permanent displacement due to liquefaction were studied using shaking table tests and numerical analysis. Rows of sand or steel piles, a continuous underground concrete or steel wall, or a wall of compacted materials were the chosen measures. In all cases, displacement of some area close to the countermeasure was decreased. The continuous wall was the most effective measure. Maximum effectiveness in all cases requires the countermeasure to reach through the bottom of the liquefied layer. 933194 F_J~tic wave propeption in compoeite media Lamb, W J; Zhu, X; McMechan, G A; Greenberg, M L; Castagna, J P
Geopkysies V57, N9, Sept 1992, P1155-1165 The effective medium theory of Kuster and Toksoz (1974) can be used to predict elastic response of a composite medium provided properties of each constituent are known. A
© 1993 Pergamon Press Ltd. Reproduction not permitted RMMS 30/3--L
164A solid/solid medium with randomly distributed octagonal cylindrical inclusions is considered and the importance of multiple scattering between inclusions is investigated using a finite difference numerical approach. The aim is estimation of elastic moduli and wave velocities from numerically generated observations for realistic constituent properties and study of the effect of inclusion distribution and shape. P and S wave velocities are computed for a number of inclusion filling factors.
Identification and classification See also: 933493
933195 C h ~ l c g t i o o of overlmrden properties for underground coal gasification: laboratory studies under high temperature and in situ stress conditions Wolf, K H A A; Hettema, M H H; De Pater, C J; Van Hooydonk, R Proc I S R M Symposhtm: Euroek'92, Chester, 14-17 September 1992 P99-104. Publ London: Thomas Telford, 1992 Roof rock above UCG cavities must withstand high temperatures and geomechanical and thermomechanical stresses. Samples of overburden claystone have been characterised in the laboratory before and after heating to temperatures up to 1400 deg C at 50 bar in nitrogen. Effects of the treatment on mineralogical, microstructural, and mechanical parameters are described. Classification parameters for the untreated and baked rock at ambient and high temperatures are evaluated using the schemes of Bieniawski and Hock and Brown. Cavity stand-up times are estimated.
933196 Design and support of inclined shafts through coal measures strata, the use of rock class/flcation Oldroyd, D C; Buddery, P S Proc I S R M SymposLum: Eurock'92, Cluster, 14-17 September 1992 P147-152. Publ London: Thomas Teiford, 1992
Coal mines in Natal are generally at shallow depth and reached by vertical or inclined shafts through Karoo sediments. Shaft design uses a rock classification system based on results of impact splitting, free swell, and slake durability tests. Weighted values from these tests are combined to define 5 rock classes, from very poor to very good. Support and some blasting practices are specified according to these classes. Two case examples of use of the classification are presented.
933197 Preliminary estimation of rock slope stability m ~ . rock mass ~ation systems Haines, A; Terbrugge, P J Proc 7th I S R M laterm~timud Co~,ress oR Rock Meckames, Aachen, 1620 September 1991 V2, P887-892. Publ Rotterdam: ~[ A Balkema, 1991 Classification schemes are often used at the preliminary stages of rock engineering projects. The Mining Rock Mass Rating (MRMR) scheme of Laubecher (1977) was originally developed in the mining industry to assess stability of underground excavations, but has now been extended for slope stability
applications. The use of the MRMR in design of slopes in a relatively homogeneous rock mass and in a range of heterogeneous rock units is presented. MRMR slope angles and those from rigorous analysis are compared. A chart is developed linking slope height, slope angle, and MRMR value, which is subdivided such that combinations for which rigorous analysis is desirable or essential are shown.
933198 Characterization of jointed rock masses for rock anchors Ebisu, S; Aydan, O; Komura, S; Kawamoto, T Proc Conference on Fractured and Jobtted Rock Masses, Lake Tahoe, 3-5 June 1992 P150-157. Pubi California: Lawrence Berkeley Laboratory, 1992 Anchor pullout tests and rock mass characterisation have been carried out at sandstone and granite sites. Distribution and geometry of the discontinuities were examined, elastic wave properties measured, and borehole jack tests carried out in the field. Physical and mechanical properties were measured on cores in the laboratory. RQD, maximum core length (MCL), and discontinuity number per lm length (DN) were evaluated. Correlations between the various geometrical, geophysical, mechanical, and empirical parameters have been studied, and their suitability for rock mass classification for anchor design is discussed.
933199 Statfmle tUmdmimmt ~ of joint~ reek masses Lin, Y M; Liu, X C Proe Conflreoce on Froctwted amf Yoksted Rock Masses, Lake Tahoe, 3-5 Jme 1992 P199-204. Publ California: Lawrence Berkeley Laboratory, 1992 A new classification method for rock masses is presented. This statistical method makes use of Fisher's discriminant analysis to establish a discriminant function for rock mass classification according to case history records and expert judgement. An optimal empirical formula is developed in terms of weighted values of UCS, joint spacing, and the square of the acoustic velocity ratio of rock mass and intact rock. Basic rock mass qualities can be adjusted to take into account effects of groundwater, field stresses, or geology.
933200 Charactedzafioo of weak, strafihd and clay bearing rock masses for engineering al~i~tions Ulusay, R; Ozkan, I; Unal, E Proc Comfereoce on Frocttwed amd Joimted Rock Masses, Lake Takoc, 3-5 J a e 1992 P233-240. Publ California: Lawrence Berkeley Laboratory, 1992
The Q and RMR systems widely used in mining and tunnelling will give misleading results if appl-h~d in weak, stratified, clay-bearing rock masses. A modified RMR system has been developed in Turkey for application in such rocks. Because of the difficulty in obtaining suitable cores for standard laboratory tests, point load tests are used to evaluate strength and anisotropy. A slake durability index term is included to take into account effects of groundwater. Parameters associated with condition of joints are weighted to represent the stratified nature and prvsence of clays, Applications of the original and modified RMR to design of slopes and underground excavations are shown.
© 1993 Pergamon Press Ltd. Reproduction not permitted