This paper introduces the modeling of the vertical pile response from time-domain wave equation analysis with the soil spring constants derived from t-z and Q-z curves and the time-dependent damping coefficients obtained from the dynamic impedance functions.

At cooperating work state, for the sake of accurately reflecting forceand distortion of pile body, this paper considers several problems as followed. Under thepit, pile locating in the passive soil pressure preferably operates with soil, which accordelastic foundation beam theory, so soil pressure is simulated as soil spring throwing onthe piles.

And the effects of the retaining wall stiffness, strut stiffness, perforce and soil spring stiffness on the internal force and deformation of the retaining structures.

1. The traditional plane computing method and traditional elastic footing beam method are modified. One-way soil spring is adopted to carry out 3D anlysis for the retaining and protecting structure.

This paper introduces the modeling of the vertical pile response from time-domain wave equation analysis with the soil spring constants derived from t-z and Q-z curves and the time-dependent damping coefficients obtained from the dynamic impedance functions.

By correcting the soil spring constant, the model can be used to obtain the design curves of pile displacements and to match the experimental data of in situ pile load tests.

This paper, in the light of construction charactristics of Dapu road tunnel acrossing the Huangpu river in Shanghai,puts forword an analysis method by use of plate element to simulate tunnel lining,lane plate and vertical brace,and of soil spring to simulate interaction between soil and tunnel.

According to the analytic results of field dynamic test of the new Luan-river bridge, the simplified mechanical model for calculating the earthquakeresponse of beam bridge structure is established with lumped masses and equi-valent soil-spring system. This system is modeled after the resisting force ofsoil layers under the ground. Taking account of the paramaters β(from theNewmark-βmethod) and θ(from the wilson-θ method), an improved numericalanalysis procedure is derived in this paper, and a complete...

According to the analytic results of field dynamic test of the new Luan-river bridge, the simplified mechanical model for calculating the earthquakeresponse of beam bridge structure is established with lumped masses and equi-valent soil-spring system. This system is modeled after the resisting force ofsoil layers under the ground. Taking account of the paramaters β(from theNewmark-βmethod) and θ(from the wilson-θ method), an improved numericalanalysis procedure is derived in this paper, and a complete program is thusdeveloped. A sketch of the old Luan-river bridge structure after the earthquake disa-ster is given, and the break-mechanism of this structure and some of the rela-ted problems in the analysis are also discussed.

In this paper earthquake accelerograms are used to analyse buried pipeline responses to seismic wave-propagation and results are compared with those of manual methods in which harmonic waves are used. The effects of soil properties. pipeline-soil slippage and wave propagation Velocity are also investigated. Several conclusions are drawn as following. 1. The dominant period of the axial pipe strain is approximately equal to that of velocity wave, not that of acceleration wave.So,when harmonic wave is used in...

In this paper earthquake accelerograms are used to analyse buried pipeline responses to seismic wave-propagation and results are compared with those of manual methods in which harmonic waves are used. The effects of soil properties. pipeline-soil slippage and wave propagation Velocity are also investigated. Several conclusions are drawn as following. 1. The dominant period of the axial pipe strain is approximately equal to that of velocity wave, not that of acceleration wave.So,when harmonic wave is used in pipeline strain calculation, the dominant period of velocity wave should be used instead of that of acceleration as proposed by some authors. 2. The effects of slippage between pipe and soil on pips strains and displacements depend on the amplitute of ground displacement and the maximum elastic relative displacement of soil spring. 3. When the ground displacement is small and there is no slippage on most of the pipe segment, the effects of the relative displacement between pipe and soil is negligible and therefore the pipe strain is almost the same as the seismic ground strain. 4. When the ground displacement is very large and slippage occuis extensively, the effects of soil properties on the pipe responses mainly depend on the pipeline-soil frictional force. The effects of slippage on relative displacement between pipe and soil is significant even if the ground displacement is relatively small.

Ia this paper, jacket platforms coupled with the surrounding water, soil and piles are idealized as 3D multi-level substructure models. The nonlinear stiffness and damping of the soil springs are linearized iteratively with the Krylov-Bogoliubov method. And the nonlinear drag forces in the Morion's formula are linearized iteratively with Borgman's assumption as the initial approximation. A multi-level reduction technique is applied to the linear parts of the platforms. And the dynamic modification...

Ia this paper, jacket platforms coupled with the surrounding water, soil and piles are idealized as 3D multi-level substructure models. The nonlinear stiffness and damping of the soil springs are linearized iteratively with the Krylov-Bogoliubov method. And the nonlinear drag forces in the Morion's formula are linearized iteratively with Borgman's assumption as the initial approximation. A multi-level reduction technique is applied to the linear parts of the platforms. And the dynamic modification is introduced into the highest level linear substructure.In the reanalyses,the modification is done only for the nonlinear stiffness and damping coefficients of the soil springs. A greatly reduced random response equation is solved in terms of a deterministic algorithm newly developed. The given examples show that the present method is both efficent and accurate.