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Geologic features and durability of limestones at the Sphinx
2A 911007 Time dependent atmospheric degradation of building stone in a polluting environment Atteweli, P B; Taylor, D Environ Geol Water Sei V16, NI, July~Aug 1990, P43-55
Durability of weathered facing stone (Low Main Post sandstone) of Durham Cathedral and of its replacement (Upper Carboniferous Millstone Grit) has been assessed during the program of progressive replacement. Porosity, permeability, and acid immersion tests were used. Factors responsible for the atmospheric weathering are discussed. Weathering rates of Carrera marble, determined from a survey of local gravestones, are also presented.
911008 Geologic features and durability of limestones at the Sphinx Gauri, K L; Chowdhury, A N; Kulshreshtha, N P; Punuru, A R Environ Geol Water Sci VI6, NI, July~Aug 1990, t'57-62
Durability of Giza Plateau limestone, Egypt, has been examined. Depositionai history, evolution of porosity, and development of joints are important, but the major cause of degradation is salt crystailisation aided by the ink-bottle pore system of the rocks. The weathering profile shows alternate layers. The less weathered rock has smaller quantities of halite and gypsum and a larger pore-to-throat ratio than the more weathered rock. Pressures generated in the pores have been calculated, based on thermodynamic principles. An equation to provide quantitative description of the durability of these rocks is derived.
911009 Internal stability of minestone den Adel, H; Bakker, K J; Breteler, M K Proc International Symposium on Modelling Soil-WaterStrRctnre Interactions, Delft, 29 August-2 September 1988 P225-231. Publ Rotterdam: A A Balkema, 1988
Minestone is a cheap waste material. Because of its wide grain size distribution, it often cannot be used as an internally stable filter material for dykes and embankments if specified according to geometrical criteria. The phenomenon of internal erosion, with small grains washed out leaving a coarse grained skeleton, has been studied using the Delft Hydraulics filter box test. Criteria for geometrical internal stability (Kenney) are verified by experimental data. A less stringent hydraulic design criterion is also developed.
Earthquake mechanisms and effects 911011 Amplification of elastic waves by a three dimensional valley. Part !: steady state response Mossessian, T K: Dravinski, M EartluI Engng Struct Dynam vIg, NS, July 1990, P667-680
Local site effects have important influence on ground motion. Steady state scattering of P, SV, SH, and Rayleigh waves by general non-axisymmetric three dimensional dipping layers of linear, homogeneous, isotropic, weakly inelastic materials is examined using a boundary element method. Results are compared systematically to those of 2D analysis. Validity of the 2D approximation for a given basin shape is affected by incidence angle, type, and frequency of the wave. The discrepancies are more marked for SH waves. Strong coupling is seen between P/SV and SH Modes, which has no correspondence in 2D models. 911012 Amplification of elastic waves by a three dimensional valley. Part 2: transient response Mossessian, T K; Dravinski, M EartlUl Engng Struct Dyamn VI9. NS, July 1990, P681-691
Transient response of three dimensional dipping layers of linear, isotropic, homogeneous, weakly inelastic material, of different shapes, when subject to incident P, SH, SV, and Rayleigh waves is examined. Fourier synthesis is used to construct time domain response from steady state solutions. Maximum amplification of motion is dependent on type and frequency of wave and basin shape. If valley shape changes from hemispherical to semi-prolate, amplitude of surface waves near the edges increases, but maximum amplification near the valley centre decreases, especially for P waves. Results are compared to those of 2D approximation. 911013 Steady state, near-source models of the Purkficld, Imperial Valley, and Mexieali Valley earthquakes Mendez, A J; Luco, J E J Geopkys Res V95, NBI, Jan 1990, P327-340
The extended steady dislocation model (Mendez and Luco, 1988) is used as a forward model for inversion of near source data for three earthquakes. The fault plane is modelled as a strip of infinite length and finite width. Inferred shape of the rupture front and distribution of slip with depth are consistent with results from more general models. The strong velocity pulse in the near source region can be modelled as the passage of the rupture front phase, and supershear propagation of the rupture front in the sedimentary layers provides a mechanism for the generation of the large amplitudes seen.
911010 Underground works in rock in Hong Kong Vail, A J Proc Semiur Rock Cavern - Hang Kong, Hang Kong, 8-9 December 1989 P1-6. Publ London: IMM, 1989
911014 Crustal strnln near the big bend of the San Andreas fault: analysis of Los Padres-Tehaehapi trilateration networks, California Eberhart-Phillips, D; Lisowski, M; Zoback, M D J Geophys Res 1/95, NB2, Feb 1990. P1139-1153
A summary of the complex geology of Hong Kong is given. The territory consists of rhyolitic tuff of considerable age through which at some later period granite has intruded. The weathered mass shows both these igneous rocks to be widespread, together with some metamorphosed sedimentary rocks, some karstic limestone and quaternary sediments. The terrain left is mountainous, and the mantle of weathered rock on many of the hillsides is colluvial, at or near a state of limiting equilbrium.
In the region considered, the San Andreas fault changes its orientation from N40W to N73W. The N40W segment is roughly parallel to the global plate motion, implying essentially pure right lateral strike slip deformation. The N73W segment is poorly oriented for a purely dextral transform boundary, but studies of crustal strain along this portion indicate nearly pure right lateral strike slip, regardless of the strike of the fault with respect to plate motion. Data from the trilateration network are analysed to explain this. Best fit is
© 1991 Pergamon Press plc. Reproduction not permitted
Durability of weathered facing stone (Low Main Post sandstone) of Durham Cathedral and of its replacement (Upper Carboniferous Millstone Grit) has been assessed during the program of progressive replacement. Porosity, permeability, and acid immersion tests were used. Factors responsible for the atmospheric weathering are discussed. Weathering rates of Carrera marble, determined from a survey of local gravestones, are also presented.
911008 Geologic features and durability of limestones at the Sphinx Gauri, K L; Chowdhury, A N; Kulshreshtha, N P; Punuru, A R Environ Geol Water Sci VI6, NI, July~Aug 1990, t'57-62
Durability of Giza Plateau limestone, Egypt, has been examined. Depositionai history, evolution of porosity, and development of joints are important, but the major cause of degradation is salt crystailisation aided by the ink-bottle pore system of the rocks. The weathering profile shows alternate layers. The less weathered rock has smaller quantities of halite and gypsum and a larger pore-to-throat ratio than the more weathered rock. Pressures generated in the pores have been calculated, based on thermodynamic principles. An equation to provide quantitative description of the durability of these rocks is derived.
911009 Internal stability of minestone den Adel, H; Bakker, K J; Breteler, M K Proc International Symposium on Modelling Soil-WaterStrRctnre Interactions, Delft, 29 August-2 September 1988 P225-231. Publ Rotterdam: A A Balkema, 1988
Minestone is a cheap waste material. Because of its wide grain size distribution, it often cannot be used as an internally stable filter material for dykes and embankments if specified according to geometrical criteria. The phenomenon of internal erosion, with small grains washed out leaving a coarse grained skeleton, has been studied using the Delft Hydraulics filter box test. Criteria for geometrical internal stability (Kenney) are verified by experimental data. A less stringent hydraulic design criterion is also developed.
Earthquake mechanisms and effects 911011 Amplification of elastic waves by a three dimensional valley. Part !: steady state response Mossessian, T K: Dravinski, M EartluI Engng Struct Dynam vIg, NS, July 1990, P667-680
Local site effects have important influence on ground motion. Steady state scattering of P, SV, SH, and Rayleigh waves by general non-axisymmetric three dimensional dipping layers of linear, homogeneous, isotropic, weakly inelastic materials is examined using a boundary element method. Results are compared systematically to those of 2D analysis. Validity of the 2D approximation for a given basin shape is affected by incidence angle, type, and frequency of the wave. The discrepancies are more marked for SH waves. Strong coupling is seen between P/SV and SH Modes, which has no correspondence in 2D models. 911012 Amplification of elastic waves by a three dimensional valley. Part 2: transient response Mossessian, T K; Dravinski, M EartlUl Engng Struct Dyamn VI9. NS, July 1990, P681-691
Transient response of three dimensional dipping layers of linear, isotropic, homogeneous, weakly inelastic material, of different shapes, when subject to incident P, SH, SV, and Rayleigh waves is examined. Fourier synthesis is used to construct time domain response from steady state solutions. Maximum amplification of motion is dependent on type and frequency of wave and basin shape. If valley shape changes from hemispherical to semi-prolate, amplitude of surface waves near the edges increases, but maximum amplification near the valley centre decreases, especially for P waves. Results are compared to those of 2D approximation. 911013 Steady state, near-source models of the Purkficld, Imperial Valley, and Mexieali Valley earthquakes Mendez, A J; Luco, J E J Geopkys Res V95, NBI, Jan 1990, P327-340
The extended steady dislocation model (Mendez and Luco, 1988) is used as a forward model for inversion of near source data for three earthquakes. The fault plane is modelled as a strip of infinite length and finite width. Inferred shape of the rupture front and distribution of slip with depth are consistent with results from more general models. The strong velocity pulse in the near source region can be modelled as the passage of the rupture front phase, and supershear propagation of the rupture front in the sedimentary layers provides a mechanism for the generation of the large amplitudes seen.
911010 Underground works in rock in Hong Kong Vail, A J Proc Semiur Rock Cavern - Hang Kong, Hang Kong, 8-9 December 1989 P1-6. Publ London: IMM, 1989
911014 Crustal strnln near the big bend of the San Andreas fault: analysis of Los Padres-Tehaehapi trilateration networks, California Eberhart-Phillips, D; Lisowski, M; Zoback, M D J Geophys Res 1/95, NB2, Feb 1990. P1139-1153
A summary of the complex geology of Hong Kong is given. The territory consists of rhyolitic tuff of considerable age through which at some later period granite has intruded. The weathered mass shows both these igneous rocks to be widespread, together with some metamorphosed sedimentary rocks, some karstic limestone and quaternary sediments. The terrain left is mountainous, and the mantle of weathered rock on many of the hillsides is colluvial, at or near a state of limiting equilbrium.
In the region considered, the San Andreas fault changes its orientation from N40W to N73W. The N40W segment is roughly parallel to the global plate motion, implying essentially pure right lateral strike slip deformation. The N73W segment is poorly oriented for a purely dextral transform boundary, but studies of crustal strain along this portion indicate nearly pure right lateral strike slip, regardless of the strike of the fault with respect to plate motion. Data from the trilateration network are analysed to explain this. Best fit is
© 1991 Pergamon Press plc. Reproduction not permitted