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Effective stress analysis of seismic response and liquefaction: theory
172A 845078 Strain dependent attenuation: observations and a proposed
mechanism Stewart, R R; Toksoz, M N; Timur, A J Geopkys Res V88, NB1, 10 Jan 1983, P546-554 Theoretical analysis and experimental verification of the large strain amplitude, pressure and crack density dependence of attenuation are presented. The observations and model suggest that attenuation in dry rocks is caused by frictional work dissipation from the rubbing together of asperities on crack surfaces. For large strain amplitudes, attenuation increases linearly with strain amplitude and crack density. 845079 Dynamics of anisotropic clays under large strains Macky, T A; Saada, A S J Geotech Engng Div ASCE VllO, NGT4, April 1984, P487504
The dynamic behaviour of cross anisotropic clays under large strains at low frequency is examined. An attempt is made to model the behaviour covering the whole spectrum of strains from small to large. Axial stresses, torsional stresses and their combinations when applied to thin long hollow cylinders lead to strains that show the influence of tridimensional states of stress on the dynamic response. The modulus degradation pattern is noticeably affected by those combined stresses. The inclinations of principal stresses play an important part in the way a clay responds to cyclic loading. Relations are suggested to predict shear moduli and damping ratios. The Ramberg-OsgoodMasing hypothesis is shown to be deficient and reduction factors are proposed to bring its prediction in line with experimental data. 845O80 Effective stress analysis of seismic response and liquefaction: theory Dikmen, S U; Ghaboussi, J J Geotech Engng Div ASCE 1/110, NGT5, May 1984, P628644
An effective stress method is presented for analysis of seismic response and liquefaction of horizontally layered saturated sand deposits, based on solution of the fully coupled equations for the granular solid and the pore fluid. A new material model for hysteretic behaviour of sands and a new effective stress path rule are presented. The shear modulus reduction and damping of the proposed model are compared with other experimentally based relations. The proposed effective stress analysis method is used to simulate shaking table tests, with results in reasonably good agreement with experimental results. The proposed method of analysis is compared with a number of other wellknown methods. Auth. 845081 Effective stress analysis of seismic response and liquefaction: case studies Ghaboussi, J; Dikmen, S U J Geotecli Engng Div ASCE 1/110, NGT5, May 1984, P645658
The effective stress method of analysis described in a companion paper is used to study the effect of various factors on the response and the liquefaction potential of saturated sands. Through a number of analyses, a comparison is made between the results of total stress analysis and effective stress analysis. Analyses are performed to study the effects of the earthquake type, peak base acceleration, depth of water table and coefficient of permeability. The influence of these factors on the pore pressure build up, characteristics of ground surface response and the liquefaction potential are studied. Auth.
845082 Dynamic shear modulus and damping ratio of rocks for a wide confining pressure range Nishi, K; Kokusho, T; Esashi, Y Proc 5th Congress of the International Society for Rock Mechanics, Melbourne, 10-15 April 1983 V2, PE223-E226. Publ Rotterdam: A. A. Balkema, 1983
A cyclic triaxial testing machine for rocks was developed, making it possible to investigate the dynamic deformation properties of rock specimens at small as well as large strain levels over a wide range of confining pressures. This paper describes the results obtained in dynamic deformation tests for shear modulus and damping ratio performed on ten kinds of rock materials, paying particular attention to the dependence of these two characteristics on the frequency, initial stress, and amplitude of strain. Auth. Classification and identification 845083 Gcomechanic classification for nssessing rock mass in Japan Nakao, K; Iihoshi, S; Koyama, S; Ryoke, K In: Rock Mechanics: Caverns and Pressure Shafts (papers to the I S R M Symposium, Aachen, 26-28 May 1982) V1, P97104. Publ Rotterdam." A. A. Balkema, 1982 845O84 New approach to quantitatively evaluate the excavation of rock masses Tao Zhen-yu; Peng Zu-zeng; Yang Zi-wen In: Rock Mechanics: Caverns and Pressure Shafts (papers to the I S R M Symposium, Aachen, 26-28 May 1982) V1, P471478. Publ Rotterdam." A. A. Balkema, 1982
A new engineering quality index of rock mass is suggested. A new rock mass classification system based upon the method of fuzzy sets is proposed.
Geology See also." 845342 845085 Porosity and hydraulic properties of sediments from the Galapagos spreading center and their relation to hydrothermal circulation in the oceanic crust Karato, S; Becker, K J Geophys Res 1/88, NB2, 10 Feb 1983, P1009-1017
The good correlation between anomalous porosity and density gradients and the present-day heat flow suggests that the high gradients may be due to active hydrothermal circulation through a thin sediment cover, which is inhibited by a thicker sediment layer. Hydraulic impedance of the sediment layer was estimated from the observed depth variation of porosity and was shown to increase rapidly with its thickness. 845086 Orientation of the stress field from breakouts in a crystalline well in a seismic active area. Letter Blumling, P; Fuchs, K; Schneider, T Phys Earth Planet Inter V33, N4, Dec 1983, P250-254
The orientation of the regional stress field in the Swabian Jura was determined from borehole breakouts caused by stress accumulation at the borehole wall. The analysis is based on caliper data recorded in the Urach 3 geothermal well within an interval
mechanism Stewart, R R; Toksoz, M N; Timur, A J Geopkys Res V88, NB1, 10 Jan 1983, P546-554 Theoretical analysis and experimental verification of the large strain amplitude, pressure and crack density dependence of attenuation are presented. The observations and model suggest that attenuation in dry rocks is caused by frictional work dissipation from the rubbing together of asperities on crack surfaces. For large strain amplitudes, attenuation increases linearly with strain amplitude and crack density. 845079 Dynamics of anisotropic clays under large strains Macky, T A; Saada, A S J Geotech Engng Div ASCE VllO, NGT4, April 1984, P487504
The dynamic behaviour of cross anisotropic clays under large strains at low frequency is examined. An attempt is made to model the behaviour covering the whole spectrum of strains from small to large. Axial stresses, torsional stresses and their combinations when applied to thin long hollow cylinders lead to strains that show the influence of tridimensional states of stress on the dynamic response. The modulus degradation pattern is noticeably affected by those combined stresses. The inclinations of principal stresses play an important part in the way a clay responds to cyclic loading. Relations are suggested to predict shear moduli and damping ratios. The Ramberg-OsgoodMasing hypothesis is shown to be deficient and reduction factors are proposed to bring its prediction in line with experimental data. 845O80 Effective stress analysis of seismic response and liquefaction: theory Dikmen, S U; Ghaboussi, J J Geotech Engng Div ASCE 1/110, NGT5, May 1984, P628644
An effective stress method is presented for analysis of seismic response and liquefaction of horizontally layered saturated sand deposits, based on solution of the fully coupled equations for the granular solid and the pore fluid. A new material model for hysteretic behaviour of sands and a new effective stress path rule are presented. The shear modulus reduction and damping of the proposed model are compared with other experimentally based relations. The proposed effective stress analysis method is used to simulate shaking table tests, with results in reasonably good agreement with experimental results. The proposed method of analysis is compared with a number of other wellknown methods. Auth. 845081 Effective stress analysis of seismic response and liquefaction: case studies Ghaboussi, J; Dikmen, S U J Geotecli Engng Div ASCE 1/110, NGT5, May 1984, P645658
The effective stress method of analysis described in a companion paper is used to study the effect of various factors on the response and the liquefaction potential of saturated sands. Through a number of analyses, a comparison is made between the results of total stress analysis and effective stress analysis. Analyses are performed to study the effects of the earthquake type, peak base acceleration, depth of water table and coefficient of permeability. The influence of these factors on the pore pressure build up, characteristics of ground surface response and the liquefaction potential are studied. Auth.
845082 Dynamic shear modulus and damping ratio of rocks for a wide confining pressure range Nishi, K; Kokusho, T; Esashi, Y Proc 5th Congress of the International Society for Rock Mechanics, Melbourne, 10-15 April 1983 V2, PE223-E226. Publ Rotterdam: A. A. Balkema, 1983
A cyclic triaxial testing machine for rocks was developed, making it possible to investigate the dynamic deformation properties of rock specimens at small as well as large strain levels over a wide range of confining pressures. This paper describes the results obtained in dynamic deformation tests for shear modulus and damping ratio performed on ten kinds of rock materials, paying particular attention to the dependence of these two characteristics on the frequency, initial stress, and amplitude of strain. Auth. Classification and identification 845083 Gcomechanic classification for nssessing rock mass in Japan Nakao, K; Iihoshi, S; Koyama, S; Ryoke, K In: Rock Mechanics: Caverns and Pressure Shafts (papers to the I S R M Symposium, Aachen, 26-28 May 1982) V1, P97104. Publ Rotterdam." A. A. Balkema, 1982 845O84 New approach to quantitatively evaluate the excavation of rock masses Tao Zhen-yu; Peng Zu-zeng; Yang Zi-wen In: Rock Mechanics: Caverns and Pressure Shafts (papers to the I S R M Symposium, Aachen, 26-28 May 1982) V1, P471478. Publ Rotterdam." A. A. Balkema, 1982
A new engineering quality index of rock mass is suggested. A new rock mass classification system based upon the method of fuzzy sets is proposed.
Geology See also." 845342 845085 Porosity and hydraulic properties of sediments from the Galapagos spreading center and their relation to hydrothermal circulation in the oceanic crust Karato, S; Becker, K J Geophys Res 1/88, NB2, 10 Feb 1983, P1009-1017
The good correlation between anomalous porosity and density gradients and the present-day heat flow suggests that the high gradients may be due to active hydrothermal circulation through a thin sediment cover, which is inhibited by a thicker sediment layer. Hydraulic impedance of the sediment layer was estimated from the observed depth variation of porosity and was shown to increase rapidly with its thickness. 845086 Orientation of the stress field from breakouts in a crystalline well in a seismic active area. Letter Blumling, P; Fuchs, K; Schneider, T Phys Earth Planet Inter V33, N4, Dec 1983, P250-254
The orientation of the regional stress field in the Swabian Jura was determined from borehole breakouts caused by stress accumulation at the borehole wall. The analysis is based on caliper data recorded in the Urach 3 geothermal well within an interval