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Clay raw materials and clay minerals in the service of man
IN SITUSTRESS:CAUSES !M8160 Seismic behviour estimation of thin ahvium Iayers using microtremor recordings P. Teves-Costa, L. Matias & P. Y. Bard, Soil Dynamics & Earthquake Engineering, 15(3), 1996, pp 201-209. In order to character&. the seismic behaviour of alluvium layers existing in Lisbon two sets of microtremor measurements were performed. The data were processed according to the Nakamura technique. The results were correlated with the thickness of the alluvium deposits and compared with the spectral ratios obtained using records from blasts, as well as with 1D theoretical models and with 2D theoretical simulations obtained by the use of the Aki-Larner technique. These comparisons seems to prove that the use of microtremor measurements could give a good contribution for the microzonation techniques, specially in urban zones. (from Authors)
968161 A aolutloa to saturated eiastic half-space under harmonic force of low frequency (in Chinese) Wang Lizhong, Chen Yunmin, Wu Shiming & Ding Haojiang, Shuili Xuebao/Joumal of Hydraulic Engineering, 2, 1996, pp 84-89. This paper utilizes a soil mechanics model to study the Lamb problem of a viscous half-space saturated with water. The operator method is adopted to solve uncoupled equations. An example is given. (English summary) 968162 Aaisotropy of small strain stiffness in Ticino sand R. Bellotti, M. Jamiolkowski, D. C. F. Lo Presti & D. A. O’Neill, Geotechnique, 46(l), 1996, pp 115-131. Teats performed in a large calibration chamber and consisting of the propagation of seismic body waves in dry Ticino silica sand are presented. Five independent constants of the crossanisotropic elasticity mode.1 of the test have been established. The tests have also made it possible to evaluate the influence. of the structural (inherent) and stress-induced anisotropy on the velocity of the propagated seismic body waves. The influence of the principal effective stresses on the velocity of these waves is also described. (from authors) 968163 Liquefaction resistance of silty sand based on in situ frozen samples Y. Yoshimi & S. Goto, Geotechnique, 46(l), 1996, pp 153156. This note supplements the paper by Yoshimi et al. (1994) by proposing a method for evaluating the in situ liquefaction resistance of silty sands on the basis of undrained cyclic tests on samples obtained by the in situ freeze sampling method that has proved successful for clean sands. (from Authors) 968164 Elasticity of partiaUy saturated frozen sand M. Jacoby, J. Dvorkin & Xingzhou Liu, Geophysics, 61(l), 1996, pp 288-293. This study is concerned with velocities in partially saturated unconsolidated sands. The experiments show that in hydrophilic granular materials, velocities may be close to their fullsaturation terminal values at saturations as small as lo-15%. The reason for this strong velocity increase from the dry state is the cementing action of ice that forms pendular rings at the grain contacts. The freezing effect is a special case of a more general phenomenon: even small amounts of relatively soft cement, if placed at the grain contacts, act to dramatically increase the tibess of the aggregate. By applying the Dvorkin et al. (1994) intergranular cementation theory, the measured experimental values are accurately predicted. (from Authors)
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351A
968165 Surface motion of a cyIindricai biiI of circuiar-arc crosssection for incident plane SH waves Xiaoming Yuan & Zhen-Peng Liao, Soil Dynamics & Earthquake Engineering, 15(3), 1996, pp 189-199. A closed-form solution of two-dimensional scattering of plane SH waves by a cylindrical hill of circular-arc crosssection in a half-space is presented using the wave functions expansion method. The solution is reduced to solving a set of infinite linear algebraic equations, using the auxiliary functions and the exterior region form of the GraPs addition theorem. The effects of the height-to-width ratio of the hill on surface ground motion are finally illustrated. (from Authors)
Identification and classification 968166 A comprehensive method of rock mass characterization for indicating natural slope instability D. F. Mazzoccola C J. A. Hudson, Quarterly Journal of Engineering Geology, 29(l), 1996, pp 37-56. Presents an application of the Rock Engineering Systems (RES) methodology for developing a new rock mass classification, sensitive to large-scale instability in natural slopes and suitable for indicating critical sites. In order to be able to have a structured approach a comprehensive method based on the RES approach was adopted. This is an object-based approach which allows the utilization of all the information related to the project, tailoring the classification to the actual circumstances. Hence those parameters which are particularly active at the site can be evaluated and the importance of their interactions established. (from Authors) 968167 Mineralogy, fabric properties and classification of weatbered granites in Hong Kong T. Y. Irfan, Quarterly Journal of Engineering Geology, 29(l), 1996, pp 5-35. A model for weathering of granites is established and, based on this, modifications are proposed to the material and mass weathering schemes commonly adopted in Hong Kong for the characterization of weathered granite in engineering uses. A number of chemical indices have heen found to be good indicators of chemical weathering whereas the micro-petrographic indices can be used to characterize most fabric elements of weathered granites. (from Author) 968168 Clay raw materials and clay minerals in the service of man J. Konta, Acta Universitatti Carolinae - Geologica, 38(2-4), 1994, pp 245-252. Clay minerals, the essential constituents of argillaceous rocks, come in seven groups classified according to their crystal structure and crystal chemistry. Clay raw materials are divided in the same way to seven groups; an eighth group covers clay ochres and pigments. Further classification in the majority of groups is based on the purpose-made technological application. This paper describes the application of clay raw materials in different industrial branches, agriculture, civil engineering, and environmental projects. (from Author)
IN SITU STRESS
Causes and nature of in situ stress 968169 State of stress in southern Italy from borebole breakout and focal mechanism data A. Amato, P. Montone & M. Cesaro, Geophysical Research Letters, 22(23), 1995, pp 3119-3122. Presents new wellbore breakout data from oil exploration wells drilled in southern Peninsular Italy, from the Tyrrhenian shelf through the Apenninic mountain belt and foredeep,
968161 A aolutloa to saturated eiastic half-space under harmonic force of low frequency (in Chinese) Wang Lizhong, Chen Yunmin, Wu Shiming & Ding Haojiang, Shuili Xuebao/Joumal of Hydraulic Engineering, 2, 1996, pp 84-89. This paper utilizes a soil mechanics model to study the Lamb problem of a viscous half-space saturated with water. The operator method is adopted to solve uncoupled equations. An example is given. (English summary) 968162 Aaisotropy of small strain stiffness in Ticino sand R. Bellotti, M. Jamiolkowski, D. C. F. Lo Presti & D. A. O’Neill, Geotechnique, 46(l), 1996, pp 115-131. Teats performed in a large calibration chamber and consisting of the propagation of seismic body waves in dry Ticino silica sand are presented. Five independent constants of the crossanisotropic elasticity mode.1 of the test have been established. The tests have also made it possible to evaluate the influence. of the structural (inherent) and stress-induced anisotropy on the velocity of the propagated seismic body waves. The influence of the principal effective stresses on the velocity of these waves is also described. (from authors) 968163 Liquefaction resistance of silty sand based on in situ frozen samples Y. Yoshimi & S. Goto, Geotechnique, 46(l), 1996, pp 153156. This note supplements the paper by Yoshimi et al. (1994) by proposing a method for evaluating the in situ liquefaction resistance of silty sands on the basis of undrained cyclic tests on samples obtained by the in situ freeze sampling method that has proved successful for clean sands. (from Authors) 968164 Elasticity of partiaUy saturated frozen sand M. Jacoby, J. Dvorkin & Xingzhou Liu, Geophysics, 61(l), 1996, pp 288-293. This study is concerned with velocities in partially saturated unconsolidated sands. The experiments show that in hydrophilic granular materials, velocities may be close to their fullsaturation terminal values at saturations as small as lo-15%. The reason for this strong velocity increase from the dry state is the cementing action of ice that forms pendular rings at the grain contacts. The freezing effect is a special case of a more general phenomenon: even small amounts of relatively soft cement, if placed at the grain contacts, act to dramatically increase the tibess of the aggregate. By applying the Dvorkin et al. (1994) intergranular cementation theory, the measured experimental values are accurately predicted. (from Authors)
& NATURE
351A
968165 Surface motion of a cyIindricai biiI of circuiar-arc crosssection for incident plane SH waves Xiaoming Yuan & Zhen-Peng Liao, Soil Dynamics & Earthquake Engineering, 15(3), 1996, pp 189-199. A closed-form solution of two-dimensional scattering of plane SH waves by a cylindrical hill of circular-arc crosssection in a half-space is presented using the wave functions expansion method. The solution is reduced to solving a set of infinite linear algebraic equations, using the auxiliary functions and the exterior region form of the GraPs addition theorem. The effects of the height-to-width ratio of the hill on surface ground motion are finally illustrated. (from Authors)
Identification and classification 968166 A comprehensive method of rock mass characterization for indicating natural slope instability D. F. Mazzoccola C J. A. Hudson, Quarterly Journal of Engineering Geology, 29(l), 1996, pp 37-56. Presents an application of the Rock Engineering Systems (RES) methodology for developing a new rock mass classification, sensitive to large-scale instability in natural slopes and suitable for indicating critical sites. In order to be able to have a structured approach a comprehensive method based on the RES approach was adopted. This is an object-based approach which allows the utilization of all the information related to the project, tailoring the classification to the actual circumstances. Hence those parameters which are particularly active at the site can be evaluated and the importance of their interactions established. (from Authors) 968167 Mineralogy, fabric properties and classification of weatbered granites in Hong Kong T. Y. Irfan, Quarterly Journal of Engineering Geology, 29(l), 1996, pp 5-35. A model for weathering of granites is established and, based on this, modifications are proposed to the material and mass weathering schemes commonly adopted in Hong Kong for the characterization of weathered granite in engineering uses. A number of chemical indices have heen found to be good indicators of chemical weathering whereas the micro-petrographic indices can be used to characterize most fabric elements of weathered granites. (from Author) 968168 Clay raw materials and clay minerals in the service of man J. Konta, Acta Universitatti Carolinae - Geologica, 38(2-4), 1994, pp 245-252. Clay minerals, the essential constituents of argillaceous rocks, come in seven groups classified according to their crystal structure and crystal chemistry. Clay raw materials are divided in the same way to seven groups; an eighth group covers clay ochres and pigments. Further classification in the majority of groups is based on the purpose-made technological application. This paper describes the application of clay raw materials in different industrial branches, agriculture, civil engineering, and environmental projects. (from Author)
IN SITU STRESS
Causes and nature of in situ stress 968169 State of stress in southern Italy from borebole breakout and focal mechanism data A. Amato, P. Montone & M. Cesaro, Geophysical Research Letters, 22(23), 1995, pp 3119-3122. Presents new wellbore breakout data from oil exploration wells drilled in southern Peninsular Italy, from the Tyrrhenian shelf through the Apenninic mountain belt and foredeep,