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Dynamic analysis of axially-loaded footings in the time domain
53A ratio, and pile tip conditions influence equivalent stiffness and damping functions of the piles and lateral and vertical displacement amplitudes. Results are compared to other theoretical output and a set of experimental data.
941418 Analytical modelling of hammer impact for pile driving Deeks, A J; Randolph, M F lnt J Num Anal Meth Geomech V17, N5, May 1993, P279302 An analytical model of hammer impact is presented based on lumped ram and anvil masses separated by a cushion with internal damping and connected to a dashpot representing the pile. Force-time histories from the model are compared to those from commonly used commercial numerical analyses of hammer models and field data. The model is then used to examine conditions leading to hammer bounce, with associated lower transference of energy to the pile.
941419 Wave equation parameters from driven-rod test Liang, R Y; Sheng, S J Geotech Engng Div ASCE Vl19, N6, June 1993, P10371057 A practical method is presented based on the driven-rod test and attendant high-strain test measurements and C A P W A P signal match procedures to determine the Smith model parameters of piles for wave equation analysis. Empirical relations are developed to allow driven rod data and prototype pile results to be correlated and extrapolated for full scale application.
941420 Improved non-reflecting boundary method for soil-structure interaction analysis Quian, L; Zhang, H Microcomput Civ Engng V8, N4, 1993, P291-297 In dynamic finite element analysis of soil-foundation interaction, the half-infinite space must be replaced by a finite region with a non-reflecting boundary for wave propagation. A nonreflecting boundary method with constant acceleration and constant force applied to the boundary is proposed and a corresponding explicit-implicit algorithm for dynamic analysis presented. Results from this approach are compared to those from accepted but more computationally intensive methods.
941421 Vertical response of single piles: transient analysis by timedomain BEM Lei, Z X; Cheung, Y K; Tham, L G Soil Dynmn Eartlul Engng V12, N1, 1993, P37-49 Transient dynamic response of a pile in a layered half space and under a time-dependent vertical force is analysed with the pile described by finite elements and the half space by a general cylindrical coordinates BEM. Compatibility and equilibrium conditions between the pile shaft and the soil layers are used to assemble the respective equations into only one. Parametric studies examine the effects of ratios of pile to soil Young's modulus and density, pile slenderness, and soil Poisson's ratio. Effects of soil layering and support condition at the pile tip are examined numerically.
941422 Dynamic analysis of axially-loaded footings in the time domain Anandarajah, A Soils Found V33, NI, March 1993, P40-54 A method for time domain analysis of footings under dynamic axial loading is proposed. Radiation effects in the horizontal direction are modelled using infinite elements, which allows the vertical boundary to be placed as close as desired to the footing. The domain outside the boundary must be horizontally layered and behave linearly. An example is evaluated where the entire domain is taken to be an isotropic, linear, viscoelastic material. Results are compared to those of a standard finite element analysis with the vertical boundary placed sufficiently far from the footing.
941423 Effects of earthquakes on settlements and axial pile response in clays Poulos, H G Trans lnst Engrs Aust Civ Engng VCE35, N1, March 1993, P43-48 A relatively simple procedure is presented for estimation of magnitude and rate of settlement developed in a clay layer under earthquake excitation. A pore pressure generation equation of Matsuda and Ohara is used in the finite difference consolidation analysis. Effects of earthquake magnitude on excess pore pressure and settlement are first evaluated, then the influence of these parameters on short-term and long-term response of piles. Adverse effects on pile performance are indicated for earthquake magnitude greater than 6 on the Richter scale.
941424 Full scale testing for the dynamic characterization of foundation piles Panzeri, P; Pezzoli, P Proc 3rd International Symposium on Field Measurements in Geomechanics, Osio, 9-11 September 1991 V2 , P697-706. Publ Rotterdam: A A Balkema, 1991 Full scale dynamic tests on single piles and pile groups are described. The tests, in which sinusoidal forces were applied at the top of the piles, were aimed at experimental determination of the mechanical impedance of the piles. A new experimentalnumerical procedure is proposed for evaluation of the influence coefficients of elastic resistance of a pile due to the presence of other piles in the group. A new experimental rig for static-dynamic combined testing is illustrated.
941425 Soil/structure seismic investigation of safety-related structures Serhan, S J; Chen, C Proc 6th ASCE Speciaflty Conference on Probabilistic Mechanics and Structural and Geotedmical Reliability, Denver, 8-10 July 1992 P396-399. Publ New York: ASCE, 1992 Earthquake events and response of two nuclear plants in the USA (V.C. Summer, South Carolina and Perry, Ohio) and at Krsko, Siovenia, are analysed. The high frequency, low energy events were non-damaging for passive equipment and rugged active components. The high frequency component was transmitted to the inside of the structures even on a soil site. Dominant frequencies of the massive structures differ greatly from those of the excitation considered. Strong soil-structure interaction was observed at Krsko and reproduced by the computer code SHAKE. Structural response in the rocking mode is seen.
941418 Analytical modelling of hammer impact for pile driving Deeks, A J; Randolph, M F lnt J Num Anal Meth Geomech V17, N5, May 1993, P279302 An analytical model of hammer impact is presented based on lumped ram and anvil masses separated by a cushion with internal damping and connected to a dashpot representing the pile. Force-time histories from the model are compared to those from commonly used commercial numerical analyses of hammer models and field data. The model is then used to examine conditions leading to hammer bounce, with associated lower transference of energy to the pile.
941419 Wave equation parameters from driven-rod test Liang, R Y; Sheng, S J Geotech Engng Div ASCE Vl19, N6, June 1993, P10371057 A practical method is presented based on the driven-rod test and attendant high-strain test measurements and C A P W A P signal match procedures to determine the Smith model parameters of piles for wave equation analysis. Empirical relations are developed to allow driven rod data and prototype pile results to be correlated and extrapolated for full scale application.
941420 Improved non-reflecting boundary method for soil-structure interaction analysis Quian, L; Zhang, H Microcomput Civ Engng V8, N4, 1993, P291-297 In dynamic finite element analysis of soil-foundation interaction, the half-infinite space must be replaced by a finite region with a non-reflecting boundary for wave propagation. A nonreflecting boundary method with constant acceleration and constant force applied to the boundary is proposed and a corresponding explicit-implicit algorithm for dynamic analysis presented. Results from this approach are compared to those from accepted but more computationally intensive methods.
941421 Vertical response of single piles: transient analysis by timedomain BEM Lei, Z X; Cheung, Y K; Tham, L G Soil Dynmn Eartlul Engng V12, N1, 1993, P37-49 Transient dynamic response of a pile in a layered half space and under a time-dependent vertical force is analysed with the pile described by finite elements and the half space by a general cylindrical coordinates BEM. Compatibility and equilibrium conditions between the pile shaft and the soil layers are used to assemble the respective equations into only one. Parametric studies examine the effects of ratios of pile to soil Young's modulus and density, pile slenderness, and soil Poisson's ratio. Effects of soil layering and support condition at the pile tip are examined numerically.
941422 Dynamic analysis of axially-loaded footings in the time domain Anandarajah, A Soils Found V33, NI, March 1993, P40-54 A method for time domain analysis of footings under dynamic axial loading is proposed. Radiation effects in the horizontal direction are modelled using infinite elements, which allows the vertical boundary to be placed as close as desired to the footing. The domain outside the boundary must be horizontally layered and behave linearly. An example is evaluated where the entire domain is taken to be an isotropic, linear, viscoelastic material. Results are compared to those of a standard finite element analysis with the vertical boundary placed sufficiently far from the footing.
941423 Effects of earthquakes on settlements and axial pile response in clays Poulos, H G Trans lnst Engrs Aust Civ Engng VCE35, N1, March 1993, P43-48 A relatively simple procedure is presented for estimation of magnitude and rate of settlement developed in a clay layer under earthquake excitation. A pore pressure generation equation of Matsuda and Ohara is used in the finite difference consolidation analysis. Effects of earthquake magnitude on excess pore pressure and settlement are first evaluated, then the influence of these parameters on short-term and long-term response of piles. Adverse effects on pile performance are indicated for earthquake magnitude greater than 6 on the Richter scale.
941424 Full scale testing for the dynamic characterization of foundation piles Panzeri, P; Pezzoli, P Proc 3rd International Symposium on Field Measurements in Geomechanics, Osio, 9-11 September 1991 V2 , P697-706. Publ Rotterdam: A A Balkema, 1991 Full scale dynamic tests on single piles and pile groups are described. The tests, in which sinusoidal forces were applied at the top of the piles, were aimed at experimental determination of the mechanical impedance of the piles. A new experimentalnumerical procedure is proposed for evaluation of the influence coefficients of elastic resistance of a pile due to the presence of other piles in the group. A new experimental rig for static-dynamic combined testing is illustrated.
941425 Soil/structure seismic investigation of safety-related structures Serhan, S J; Chen, C Proc 6th ASCE Speciaflty Conference on Probabilistic Mechanics and Structural and Geotedmical Reliability, Denver, 8-10 July 1992 P396-399. Publ New York: ASCE, 1992 Earthquake events and response of two nuclear plants in the USA (V.C. Summer, South Carolina and Perry, Ohio) and at Krsko, Siovenia, are analysed. The high frequency, low energy events were non-damaging for passive equipment and rugged active components. The high frequency component was transmitted to the inside of the structures even on a soil site. Dominant frequencies of the massive structures differ greatly from those of the excitation considered. Strong soil-structure interaction was observed at Krsko and reproduced by the computer code SHAKE. Structural response in the rocking mode is seen.