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A novel structure of sheet-pile groin consists of row piles and tied sheet has been introduced to resist the impact of tidal bore in recent years. However, the dynamic responses of the structure under tidal bore have not been carefully studied before. This paper proposed an analytical solution for the dynamic responses of the sheet-pile groin subjected to a transient lateral excitation. In order to take the flexural and longitudinal vibrations into consideration, the piles and the sheet are modeled by the Timoshenko beam (TB) theory and a one-dimensional rod, respectively. The soil around the piles is simulated by the dynamic Winkler foundation model. The excitation is considered by a lateral concentrated point load acting on the front pile. On this basis, the governing equations are constructed in time domain and solved in frequency domain, while the time-domain responses are finally obtained using the discrete Inverse Fourier Transform. The accuracy of the presented analytical solution is validated by comparing with the results obtained from the FEM simulation and a model test. The effects of properties of the sheet, the piles and the soil on the dynamic responses are investigated through a comprehensive parametric study.

The sedimentation process of granular materials exists ubiquitously in nature and many fields which involve the solid-liquid separation. This paper employs the coupled computational fluid dynamics and discrete element method (CFD-DEM) to investigate the sedimentation process of non-cohesive particles, including the hindered settling stage and the deposition stage. Firstly, the coupled CFD-DEM model for sedimentation is validated by the hindered settling velocity at different solid volume concentrations of suspension (0.05~0.6). Two typical modes of sedimentation are also presented by the concentration profiles and the equal-concentration lines. Then, the comparisons between mono- and poly-dispersed particle system are detailed. In the sedimentation of the poly-dispersed particle system, the segregation phenomenon is simulated. Furthermore, this segregation effect reduces with the increase of the initial solid concentration of suspension. From the simulations, the contact force between every pair of particles can be obtained, hence we demonstrate the "effective stress principle" from the view of the particle contact force by giving the correspondence between the particle contact force and the "effective stress", which is a critical concept of soil mechanics. We also demonstrate the effective stress principle from the view of the contact force acting on particles. Moreover, the deposition stage can be simulated by CFD-DEM method, therefore the solid concentrations of sediment bed on different conditions are studied. Based on the simulation results of maximum solid concentration and the theory of sedimentation, this paper also discusses a method to calculate the critical time when sedimentation ends of two typical modes of sedimentation.

On the basis of Terzaghi’s one-dimensional consolidation theory, the variation of effective stress ratio in layered saturated soils with impeded boundaries under time-dependent loading was studied. By the method of Laplace transform, the solution was presented. Influences of different kinds of cyclic loadings and impeded boundaries conditions were discussed. Through numerical inversion of Laplace transform, useful illustrations were given considering several common time-dependent loadings. Pervious or impervious boundary condition is just the special case of the problem considered here. Compared with average index method, the results from the method illustrated are more accurate.

The variation of effective stress ratio of stratfied soil with semi-pervious boundaries and under cyclic loading was analyzed on the basis of Terzagh's one-dimensional consolidation assumptions. A solution by Laplace Transform was obtained for the case when the soil was under time-varied loading. With numerical inversion of Laplace Transform, some useful results were obtained for several kinds of commonly encountered loadings. The results can be meaningful in engineering practice.

The consolidation behavior of mixed in place cement- and lime/cement-mixed column was studied. Consolidation of the composite foundation was modeled as a three-dimensional axi-symmetric problem. The authors used the finite difference method to obtain the pore pressure variation with time at any location below the surface. A computer program developed by the authors was used to draw some interesting conclusions about the consolidation behaviors of cement- and lime/cement-mixed pile foundation. Finally, a combined model including the permeability coefficients of cement-mixed piles and soil, was studied and its feasibility was evaluated.

This paper presents a theoretical model and new idea for designing granular fill oil-tanks foundation. The finite difference method was used to analyze the influence of the oil-tanks radius, the modulus, and thickness of the granular fill on the maximum and differential settlement of a granular fill foundation of oiltanks. Comparison of the modelled results with those of traditional method and observation showed that the new method could be used efficiently in practice.

Based on the layered visco-elastic soil model, according to the Terzaghi's one dimensional consolidation theory, by the method of Laplace transform and matrix transfer technique, the problems about the consolidation of layered and saturated visco-elastic soils under arbitrary loading were solved. Through deductions, the general solution, in the terms of layer thickness, the modulus and the coefficients of permeability and Laplacian transform's parameters was obtained. The strain and deformation of the layered and saturated visco-elastic soils under arbitrary loading can be calculated by Laplace inversion. According to the results of several numerical examples, the consolidation of visco-elastic soils lags behind that of elastic soils. The development of effective stress and the displacement is vibrant process under cyclic loading. Finally, an engineering case is studied and the results prove that the methods are very effective.

Biot's two-phase theory for fluid-saturated porous media was applied in a study carried out to investigate the influence of water saturation on propagation of elastic wave in transversely isotropic nearly saturated soil. The characteristic equations for wave propagation were derived and solved analytically. The results showed that there are four waves: the first and second quasi-longitudinal waves (QP1 and QP2), the quasi-transverse wave (QSV) and the anti-plane transverse wave (SH). Numerical results are given to illustrate the influence of saturation on the velocity, dispersion and attenuation of the four body waves. Some typical numerical results are discussed and plotted. The results can be meaningful for soil dynamics and earthquake engineering.