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Analytical solution for two-dimensional dynamic consolidation in frequency domain
PROPERTIES:DYNAMICS
Dynamic properties 964122 Computation of dynamic pamdve earth pressure using L I S P E. E. Morrison Jr & R. M. Ebcling, Journal of Computing in Civil Engineering - ASCE, 9(4), 1995, pp 285-291. Outlines the development of a computer-program-based solution assuming a log-spiral failure surface to compute psuedostatic dynamic passive earth pressure coefficients. The programming language COMMON LISP was used to develop the code. This paper illustrates the use of COMMON LISP in the formulation and solution of computationally intensive algorithms. (from Author) 964123 Faraday resonance in thin sedimentary layers M. A. Fads & Yuh-Huei Chang, Geophysical Journal International, 123(2), 1995, pp 559-571. This paper explains short-scale variability in amplification factors by proposing a novel seismic resonance mechanism in thin fiat layers. The variability is attributed to the subharmanic generation of standing elastic waves on the surface of the deposit. A perturbation theory is worked out to describe the conditions for resonance, and a small shaking-tank experiment is conducted to confirm some of the theoretical findings. (from Authors) 964124 ProbabiiJstie evaluation of liquefaction potential under earthquake loading C. H. Loh & C. R. Chang, Soil Dynamics & Earthquake Engineering, 14(4), 1995, pp 269-278. This paper presents a procedure to perform the risk analysis for ground failure by liquefaction. The fn'st part of this study describes the differential equation of a smooth hysteretic model to characterize the behavior of the soil under random loading. The second part of this study develops a method to calculate the probability that a specified volume of soil will liquefy at a given depth in the deposit. Finally, the probability of liquefaction is obtained by integration over all the possible ground motion and the fragility curves of liquefaction potential. The sensitivity of the reliability against liquefaction to soil system parameters is also examined. (from Authors) 964125 Seismic response for alluvial valleys subjected to SH, P and SV waves K. L. Fishman & S. Abroad, Soil Dynamics & Earthquake Engineering, 14(4), 1995, pp 249-258. The investigation has been conducted using a rigorous boundary element algorithm. The influence of key parameters, such as, valley depth, impedance ratio, frequency, and angle of incidence on surface ground motion are studied in detail. The case of a valley within a layered half-space is analyzed and results compared with those obtained for a valley within a homogeneous half-space. (from Authors) 964126 Seismic response of shallow alluvial valleys: the use of simplified models J. L. Rodriguez-Zuniga, F. J. Sanchez-Sesma & L. E. PerezRocha, Bulletin - Seismological Society of America, 85(3), 1995, pp 890-899. The method proposed is based on the exact solution for a simple configuration. Namely, the antiplane response of a rectangular deposit with a moving rigid base. In such a solution, which is used as a framework for the approximations, the spectral signature of locally generated surface waves is explicit. Thus, an approximate expression is constructed to separately account for one-dimensional (1D) response and lateral effects. Results are presented for two- and threedimensional cases. (from Authors)
163A
964127 Azimuth dependent wave amplification in alluvial valleys H. A. Pedersen, M. Campillo & F. J. Sanchez-Sesma, Soil Dynamics & Earthquake Engineering, 14(4), 1995, pp 289300. An extension of the indirect boundary element method (IBEM) to thrce-dimansional scattering by two-dimensional alluvial valleys is presented. A parametric study with simulations for a range of azimuths and incidence angles shows that: 1) the local amplification depends strongly on both azimuth and incidence of the incoming waves, 2) the global pattern of amplification across the valley is very complex for all azimuths, and 3) it is not possible to predict the 3D response of the valley from 2D modelling. (from Authors) 964128 Sediment-induced amplification in the northeastern United States: a case study in providence, Rhode Island K. M. Fischer, L. A. Salvati, S. E. Hough, E. Gonzalez, C. E. Nelsen & E. G. Roth, Bulletin - Seismological Society of America, 85(5), 1995, pp 1388-1397. The authors employed ambient-noise measurements to assess the potential for seismic site response in sediment-filled valleys that intersect beneath downtown Providence, Rhode Island. At eight valley stations and at two rites on an adjacent bedrock highland, ground motion was recorded from two types of sources: pile drivers at a local construction site and ambient mierotrernors. At all valley sites where sediment thicknesses exceed 10 m, spectral ratios contain amplitude peaks at frequencies of 1.5 to 3.0 Hz. In contrast, spectral ratios from the two sites on the bedrock highland where sediment cover is less than 4-m thick are relatively flat within this frequency range. A variety of borehole logs identified two fundamental sediment types (soft sediment and a consolidated glacial till) and were used to map layer thicknesses over the entire study region. Concludes that unconsolidated sediment layers under downtown Providence have the potential to amplify earthquake ground motion at frequencies damaging to engineering structures. (from Authors) 964129 Direct shear tests on Mexico City clay with reference to friction pile behavinur E. Ovando-Shelley, Geotechnicai & Geological Engineering, 13(1), 1995, pp 1-16. Presents results of static and cyclic direct shear tests performed on undisturbed and rernoulded samples of Mexico City clays. Experiments show that the static adhesion coefficient depends on the soils' liquidity index and that it diminishes due to the effect of repeated dynamic loads. Dynamic overstrength effects were not apparent. Interface strength in remoulded clays is initially less than half the strength of interfaces with undisturbed materials but it increases with time. At least in the materials tested in this research, it did not equal the strength of interfaces with undisturbed materials. (from Author) 964130 Analytical solution for two-dimensional dynmie consolidation in frequency domain S. Valliappan, J. T. Yazdi & C. Zhao, International Journal for Numerical & Analytical Methods in Geomechanics, 19(10), 1995, pp 663-682. An anlytical solution to the two-dimensional wave propagation in fluid-saturated half-space subjected to a strip load with vertical harmonic oscillation at the surface is presented. The basic equations have been derived on the basis of Biot's linear theory of poro-elasticity and then solved using Fourier complex transform for the horizontal direction. It is shown that the effect of pore fluid is dominant only for fully saturated soils with incompressible solid grains and low permeability. For partially saturated, compressible or very permeable soils, the stresses would be mainly transferred to solid part and there will be considerable reduction in pore pressure amplitude. (from Authors)
Dynamic properties 964122 Computation of dynamic pamdve earth pressure using L I S P E. E. Morrison Jr & R. M. Ebcling, Journal of Computing in Civil Engineering - ASCE, 9(4), 1995, pp 285-291. Outlines the development of a computer-program-based solution assuming a log-spiral failure surface to compute psuedostatic dynamic passive earth pressure coefficients. The programming language COMMON LISP was used to develop the code. This paper illustrates the use of COMMON LISP in the formulation and solution of computationally intensive algorithms. (from Author) 964123 Faraday resonance in thin sedimentary layers M. A. Fads & Yuh-Huei Chang, Geophysical Journal International, 123(2), 1995, pp 559-571. This paper explains short-scale variability in amplification factors by proposing a novel seismic resonance mechanism in thin fiat layers. The variability is attributed to the subharmanic generation of standing elastic waves on the surface of the deposit. A perturbation theory is worked out to describe the conditions for resonance, and a small shaking-tank experiment is conducted to confirm some of the theoretical findings. (from Authors) 964124 ProbabiiJstie evaluation of liquefaction potential under earthquake loading C. H. Loh & C. R. Chang, Soil Dynamics & Earthquake Engineering, 14(4), 1995, pp 269-278. This paper presents a procedure to perform the risk analysis for ground failure by liquefaction. The fn'st part of this study describes the differential equation of a smooth hysteretic model to characterize the behavior of the soil under random loading. The second part of this study develops a method to calculate the probability that a specified volume of soil will liquefy at a given depth in the deposit. Finally, the probability of liquefaction is obtained by integration over all the possible ground motion and the fragility curves of liquefaction potential. The sensitivity of the reliability against liquefaction to soil system parameters is also examined. (from Authors) 964125 Seismic response for alluvial valleys subjected to SH, P and SV waves K. L. Fishman & S. Abroad, Soil Dynamics & Earthquake Engineering, 14(4), 1995, pp 249-258. The investigation has been conducted using a rigorous boundary element algorithm. The influence of key parameters, such as, valley depth, impedance ratio, frequency, and angle of incidence on surface ground motion are studied in detail. The case of a valley within a layered half-space is analyzed and results compared with those obtained for a valley within a homogeneous half-space. (from Authors) 964126 Seismic response of shallow alluvial valleys: the use of simplified models J. L. Rodriguez-Zuniga, F. J. Sanchez-Sesma & L. E. PerezRocha, Bulletin - Seismological Society of America, 85(3), 1995, pp 890-899. The method proposed is based on the exact solution for a simple configuration. Namely, the antiplane response of a rectangular deposit with a moving rigid base. In such a solution, which is used as a framework for the approximations, the spectral signature of locally generated surface waves is explicit. Thus, an approximate expression is constructed to separately account for one-dimensional (1D) response and lateral effects. Results are presented for two- and threedimensional cases. (from Authors)
163A
964127 Azimuth dependent wave amplification in alluvial valleys H. A. Pedersen, M. Campillo & F. J. Sanchez-Sesma, Soil Dynamics & Earthquake Engineering, 14(4), 1995, pp 289300. An extension of the indirect boundary element method (IBEM) to thrce-dimansional scattering by two-dimensional alluvial valleys is presented. A parametric study with simulations for a range of azimuths and incidence angles shows that: 1) the local amplification depends strongly on both azimuth and incidence of the incoming waves, 2) the global pattern of amplification across the valley is very complex for all azimuths, and 3) it is not possible to predict the 3D response of the valley from 2D modelling. (from Authors) 964128 Sediment-induced amplification in the northeastern United States: a case study in providence, Rhode Island K. M. Fischer, L. A. Salvati, S. E. Hough, E. Gonzalez, C. E. Nelsen & E. G. Roth, Bulletin - Seismological Society of America, 85(5), 1995, pp 1388-1397. The authors employed ambient-noise measurements to assess the potential for seismic site response in sediment-filled valleys that intersect beneath downtown Providence, Rhode Island. At eight valley stations and at two rites on an adjacent bedrock highland, ground motion was recorded from two types of sources: pile drivers at a local construction site and ambient mierotrernors. At all valley sites where sediment thicknesses exceed 10 m, spectral ratios contain amplitude peaks at frequencies of 1.5 to 3.0 Hz. In contrast, spectral ratios from the two sites on the bedrock highland where sediment cover is less than 4-m thick are relatively flat within this frequency range. A variety of borehole logs identified two fundamental sediment types (soft sediment and a consolidated glacial till) and were used to map layer thicknesses over the entire study region. Concludes that unconsolidated sediment layers under downtown Providence have the potential to amplify earthquake ground motion at frequencies damaging to engineering structures. (from Authors) 964129 Direct shear tests on Mexico City clay with reference to friction pile behavinur E. Ovando-Shelley, Geotechnicai & Geological Engineering, 13(1), 1995, pp 1-16. Presents results of static and cyclic direct shear tests performed on undisturbed and rernoulded samples of Mexico City clays. Experiments show that the static adhesion coefficient depends on the soils' liquidity index and that it diminishes due to the effect of repeated dynamic loads. Dynamic overstrength effects were not apparent. Interface strength in remoulded clays is initially less than half the strength of interfaces with undisturbed materials but it increases with time. At least in the materials tested in this research, it did not equal the strength of interfaces with undisturbed materials. (from Author) 964130 Analytical solution for two-dimensional dynmie consolidation in frequency domain S. Valliappan, J. T. Yazdi & C. Zhao, International Journal for Numerical & Analytical Methods in Geomechanics, 19(10), 1995, pp 663-682. An anlytical solution to the two-dimensional wave propagation in fluid-saturated half-space subjected to a strip load with vertical harmonic oscillation at the surface is presented. The basic equations have been derived on the basis of Biot's linear theory of poro-elasticity and then solved using Fourier complex transform for the horizontal direction. It is shown that the effect of pore fluid is dominant only for fully saturated soils with incompressible solid grains and low permeability. For partially saturated, compressible or very permeable soils, the stresses would be mainly transferred to solid part and there will be considerable reduction in pore pressure amplitude. (from Authors)