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This paper is dedicated to predict the vibration of water-saturated poroelastic ground induced by high speed train with a number of carriages. The model for the railway track consists of two rails with sleepers on water-saturated poroelastic half-space. The axle loading of the train is moving at a constant speed. The poroelastic half-space is characterized by Biot’s dynamic poroelastic theory, and the general solutions are obtained by Fourier transform. The solution of the steady-state deflection of the rails is obtained in a semi-analytical form, and the vertical deflection of foundation and its dependence on the velocity of the train is analyzed. Analyses show that the methods dealing with the elastic soil medium are only limited to the response of low train speed. The effects of damping property and the intrinsic permeability of the soil on the dynamic response show significant difference with the increase of train speed. The effect of the number of sleepers under the rails is also examined. Excellent agreement with the exiting solutions validates the present model. [ABSTRACT FROM AUTHOR]

SUMMARY This paper is dedicated to study the dynamic response of a thin-plate resting on a layered poroelastic half-space under a moving traffic load. Based on the dynamic poroelastic theory of Biot, the general solutions of the homogeneous poroelastic foundation are obtained by Fourier translation. By using the transmission and reflection matrices method in the frequency domain, the equivalent stiffness of the layered poroelastic half-space is presented. Kirchhoff's hypotheses are applied to obtain the vertical displacement of the thin plate. By using the inverse Fourier transform, the time domain solution is obtained. As an example of three layers, the influences of the load velocity, the material properties of poroelastic layers, and the flexural rigidity of the plate on the response of the pavement system are examined. Analyses show that a soft intermediate layer results in the significant increase of vertical displacement of road pavement. Comparison with the existing work validates the present model. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A newly adaptive noise reduction method based on fractional Fourier transform is presented, the core of which is the different correlativity of different signals in the field of fractional Fourier transform. This method could present an adaptive filter from the measured signals themselves, and avoid the defect of traditional filter where one must determine the location and amplitude of window function in time or frequency domain. Based on the comparison of this method with the filter constructed by wavelet transform, the feasibility and effectiveness of new method is verified through simulated and measured signals. [ABSTRACT FROM AUTHOR]