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Large strain static and dynamic semisaturated soil behaviour
214A
PROPERTIESzDEFORMATION
components and forms an intricate and anisotropic microstructure. The shape, orientation, and connection of the two phases control with anisotropic elastic properties of the composite solid. A theoretical framework that allows us to predict the effective elastic properties of shales is developed. Its usefulness is demonstrated with numerical modeling and by comparison with established ultrasonic laboratory experiments. (from Authors) 955101 Coal deformation under high temperature and confining pressure (in Chinese) Zhou Jianxun, Wang Guiliang & Zhao Zhenjie, Journal of China Coal Society, 19(3), 1994, pp 324-332. To study mechanism of tectonic deformation of coal, three samples of different ranks were tested under conditions of T = 300-7OOC, P, = 400600 MPa, E = 10% -30% and E = 3.63 x lo6 -2.59 x 1tJ5i’. The characteristics of stress-strain curves and deformation structures, especially microstructure of samples indicate that: 1) plastic deformation of coal gradually decreases with the increase of coal rank and disappears gradually; 2) the presence of gas causes obvious decrease in coal strength and has a very important effect on the mechanical properties of coal; 3) a great quantity of gas in coal can not only a decrease coal strength but also can pulverize the coal, thus effecting rheology of coal. (from English summary) 955102 Analysis of optical fabrics in experimentally deformed coals (in Chinese) Zhou Jianxun, Shao Zhenjie Jc Wang Guiliang, Scientia Geologica Sinica, 29(3), 1994, pp 276-290. Deformation experiments were performed on 3 coal samples whose R”- is 0.67%, 3.41% and 4.90% respectively. Results show that: 1) The origin of vitrinite reflectance optical fabrics is caused by the reorientation of graphite-like aromatic lamellae under tectonic stress. 2) The reorientation of aromatic lamellae takes place dominantly in the stage of relatively low coal rank. 3) Features of VRI’s shape not only are related with the condition of finite strain, but also depend on the variation of aromaticity in vitrinite to a great extent. (from English summary) 955103 Geotechnical properties of the Ptolemais lignite M. Kawadas, B. Papadopoulos 8z N. Kaltexiotis, Geofechnical & Geological Engineering, 12(2), 1994, pp 87-l 12. The paper describes an investigation of the geotechnical properties of the Ptolemais lignite (brown coal) and shows that the soil mechanics principles used in the study of natural and cemented soils are applicable. The material has a high and variable void ratio incompatible with its preconsolidation pressure, which may he attributed to the existence Of StNCtWe (chemical bonding). The properties of the Ptolemais lignite are compared with the properties of a lignite from another location in Greece and an Australian lignite. It is shown that the shear strength characteristics of the lignite types studied are similar and strongly dependent on the irr situ moisture content, which seems to be a measure of the magnitude of inter-particle bonding. (from Authors) 955184 A survey of the engineering properties of some anhydrite and gypsum from the north and midlands of England F. G. Bell, Engineering Geology, 38(1-2), 1994, pp l-23. The Permian and Triassic systems in the north and midlands of England contain notable beds of anhydrite and gypsum. Anhydrite is a strong to very strong rock in terms of both its unconfined compressive strength and point load index, whereas gypsum is of medium strength according to its
& STRENGTH
unconfined compressive strength. Because of the low porosity of these rocks, porosity does not have a significant influence on their strength. However, the strength and hardness of these rocks are strongly correlated. Most anhydrite and gypsum exhibit plastic-elastic-plastic deformation, subsequent plastic deformation occurring at an earlier stage during loading of gypsum than of anhydrite.. As far as deformability is concerned, that of anhydrite is very low while that of gypsum varies from low to high. (from Author) 955105 Large strain static and dynamic semisaturated soil behaviour E. A. Meroi, B. A. Schrefler L 0. C. Zienkiewicz, International Journal for Numerical & Analytical in Geomechanics, 19(2), 1995, pp 81-106.
MethoaIs
The theoretical and computational aspects of large strain static and dynamic partially saturated soil analysis are presented. The soil is assumed to be a three-phase material with a solid phase which may yield according to a generalized plasticity theory, whose liquid phase flows according to Darcy’s law and where gaseous phase remains equal to the external ambient pressure. Permeability varies not only as a function of the degree of water saturation, but also as a function of the void ratio. These aspects are shown on several examples. (Authors) 955106 Effects of compaction on soil strength parameters J. Guerif, in: Soil compaction in crop production, ed B.D. Soane & C. Van Ouwerkerk, (Elsevier Science; Developments in Agricultural Engineering, ll), 1994, pp 191-214. Physical and chemical origins as well as basic theoretical aspects of soil strength are presented. The effects of soil structure and organ&&on, soil constitution (mineral and organic) and water content, are outlined. It is concluded that different scales of observation and measurement are necessary to analyse soil strength origins and to determine changes in field soils. The variety in measurement techniques, due to the wide field of research where soil strength is involved, is outlined. The different methods are briefly reviewed as well as their fields of application and their limitations. Factors influencing soil strength, as induced by compaction, are investigated. (from Author) 955107 Consolidation and shear strength properties of a laterltic soil U. Mahalinga-Iyer & D. J. Williams, Engineering Geology, 38(1-2), 1994, pp 53-63. The consolidation and shear strength behaviour of a la&tic soil developed on Tertiary basalt in southeast Queensland, Australia has been investigated. Oedometer tests were performed on remoulded specimens of the soil, and on a specimen obtained from an undisturbed block sample. Primary consolidation took place rapidly, and the total settlement over the applied stress range was small. The analysis of secondary compression showed that this behaviour can be modelled satisfactorily using existing theory. The results of direct shear strength tests performed on remoulded specimens showed that the soil has a high shear strength despite its appreciable clay content. This is due to the cementation bonds between the particles at the micro-level. (from Authors) 955108 Interpretation of cone penetration results in multilayered So&i R. Vreugdenhil, R. Davis & J. Berrill, International Journal for Numerical & Analytical Methods in Geomechanics, 18(9), 1994, pp 585-599.
PROPERTIESzDEFORMATION
components and forms an intricate and anisotropic microstructure. The shape, orientation, and connection of the two phases control with anisotropic elastic properties of the composite solid. A theoretical framework that allows us to predict the effective elastic properties of shales is developed. Its usefulness is demonstrated with numerical modeling and by comparison with established ultrasonic laboratory experiments. (from Authors) 955101 Coal deformation under high temperature and confining pressure (in Chinese) Zhou Jianxun, Wang Guiliang & Zhao Zhenjie, Journal of China Coal Society, 19(3), 1994, pp 324-332. To study mechanism of tectonic deformation of coal, three samples of different ranks were tested under conditions of T = 300-7OOC, P, = 400600 MPa, E = 10% -30% and E = 3.63 x lo6 -2.59 x 1tJ5i’. The characteristics of stress-strain curves and deformation structures, especially microstructure of samples indicate that: 1) plastic deformation of coal gradually decreases with the increase of coal rank and disappears gradually; 2) the presence of gas causes obvious decrease in coal strength and has a very important effect on the mechanical properties of coal; 3) a great quantity of gas in coal can not only a decrease coal strength but also can pulverize the coal, thus effecting rheology of coal. (from English summary) 955102 Analysis of optical fabrics in experimentally deformed coals (in Chinese) Zhou Jianxun, Shao Zhenjie Jc Wang Guiliang, Scientia Geologica Sinica, 29(3), 1994, pp 276-290. Deformation experiments were performed on 3 coal samples whose R”- is 0.67%, 3.41% and 4.90% respectively. Results show that: 1) The origin of vitrinite reflectance optical fabrics is caused by the reorientation of graphite-like aromatic lamellae under tectonic stress. 2) The reorientation of aromatic lamellae takes place dominantly in the stage of relatively low coal rank. 3) Features of VRI’s shape not only are related with the condition of finite strain, but also depend on the variation of aromaticity in vitrinite to a great extent. (from English summary) 955103 Geotechnical properties of the Ptolemais lignite M. Kawadas, B. Papadopoulos 8z N. Kaltexiotis, Geofechnical & Geological Engineering, 12(2), 1994, pp 87-l 12. The paper describes an investigation of the geotechnical properties of the Ptolemais lignite (brown coal) and shows that the soil mechanics principles used in the study of natural and cemented soils are applicable. The material has a high and variable void ratio incompatible with its preconsolidation pressure, which may he attributed to the existence Of StNCtWe (chemical bonding). The properties of the Ptolemais lignite are compared with the properties of a lignite from another location in Greece and an Australian lignite. It is shown that the shear strength characteristics of the lignite types studied are similar and strongly dependent on the irr situ moisture content, which seems to be a measure of the magnitude of inter-particle bonding. (from Authors) 955184 A survey of the engineering properties of some anhydrite and gypsum from the north and midlands of England F. G. Bell, Engineering Geology, 38(1-2), 1994, pp l-23. The Permian and Triassic systems in the north and midlands of England contain notable beds of anhydrite and gypsum. Anhydrite is a strong to very strong rock in terms of both its unconfined compressive strength and point load index, whereas gypsum is of medium strength according to its
& STRENGTH
unconfined compressive strength. Because of the low porosity of these rocks, porosity does not have a significant influence on their strength. However, the strength and hardness of these rocks are strongly correlated. Most anhydrite and gypsum exhibit plastic-elastic-plastic deformation, subsequent plastic deformation occurring at an earlier stage during loading of gypsum than of anhydrite.. As far as deformability is concerned, that of anhydrite is very low while that of gypsum varies from low to high. (from Author) 955105 Large strain static and dynamic semisaturated soil behaviour E. A. Meroi, B. A. Schrefler L 0. C. Zienkiewicz, International Journal for Numerical & Analytical in Geomechanics, 19(2), 1995, pp 81-106.
MethoaIs
The theoretical and computational aspects of large strain static and dynamic partially saturated soil analysis are presented. The soil is assumed to be a three-phase material with a solid phase which may yield according to a generalized plasticity theory, whose liquid phase flows according to Darcy’s law and where gaseous phase remains equal to the external ambient pressure. Permeability varies not only as a function of the degree of water saturation, but also as a function of the void ratio. These aspects are shown on several examples. (Authors) 955106 Effects of compaction on soil strength parameters J. Guerif, in: Soil compaction in crop production, ed B.D. Soane & C. Van Ouwerkerk, (Elsevier Science; Developments in Agricultural Engineering, ll), 1994, pp 191-214. Physical and chemical origins as well as basic theoretical aspects of soil strength are presented. The effects of soil structure and organ&&on, soil constitution (mineral and organic) and water content, are outlined. It is concluded that different scales of observation and measurement are necessary to analyse soil strength origins and to determine changes in field soils. The variety in measurement techniques, due to the wide field of research where soil strength is involved, is outlined. The different methods are briefly reviewed as well as their fields of application and their limitations. Factors influencing soil strength, as induced by compaction, are investigated. (from Author) 955107 Consolidation and shear strength properties of a laterltic soil U. Mahalinga-Iyer & D. J. Williams, Engineering Geology, 38(1-2), 1994, pp 53-63. The consolidation and shear strength behaviour of a la&tic soil developed on Tertiary basalt in southeast Queensland, Australia has been investigated. Oedometer tests were performed on remoulded specimens of the soil, and on a specimen obtained from an undisturbed block sample. Primary consolidation took place rapidly, and the total settlement over the applied stress range was small. The analysis of secondary compression showed that this behaviour can be modelled satisfactorily using existing theory. The results of direct shear strength tests performed on remoulded specimens showed that the soil has a high shear strength despite its appreciable clay content. This is due to the cementation bonds between the particles at the micro-level. (from Authors) 955108 Interpretation of cone penetration results in multilayered So&i R. Vreugdenhil, R. Davis & J. Berrill, International Journal for Numerical & Analytical Methods in Geomechanics, 18(9), 1994, pp 585-599.