Rayleigh Wave Research Based On Wavelet Transform And Response Of The Utility Tunnel

A utility tunnel is a modern, intensive lifeline infrastructure by two or more lines placed in the same artificial spaces, which is the development direction of urban modernization.The utility tunnel is the shallow buried underground structure that Rayleigh wave has important effect. The utility tunnel under Rayleigh wave’s response analysis has important theoretical and practical significance. In reality, the earthquake record of the Rayleigh wave is rare, however. So how to get the Rayleigh wave is the first important thing.In this paper, the multi-scale wavelet transform technology is adopted to decompose the seismic wave, the high frequency component of the seismic wave is filtered, low frequency seismic wave is reconstructed, and assume that the reconstructed seismic wave is obtained horizontal component of Rayleigh waves. Then according to the wave equation of Rayleigh wave in soils, the vertical component of Rayleigh is obtained by Fourier transform. According to Rayleigh wave attenuation characteristics along the depth the entire Rayleigh wave field is obtained. Finally the whole analysis model is established based on finite element software ABAQUS, the obtained approximate Rayleigh wave load on the underground pipe rack structure, and research the earthquake response of the structure.Researches show that:①The orthogonal wavelet function is better than the "classic wavelet" function to obtain good results, it has this kind of frequency seismic waves constantly changing over time with good non-stationary signals local time-frequency features, and wavelet orthogonal symmetric wavelets with compact support function better..②Wavelet transform decomposition level selection part in the low-frequency coefficients can clearly show that the characteristics of the Rayleigh surface wave phases, and should not be too large or too small.③Threshold selected in the wavelet transform has important significance in the selection of different soft threshold wavelet coefficient filtering process, the global threshold, both to ensure the properties of the original signal, and without losing the energy of the original signal.④Rayleigh wave along the depth of the soil in the flat field amplitude wave theory and fast Fourier transform is constant attenuation, in line with the characteristics of the Rayleigh wave.⑤we can clearly see the utility tunnel is based on bending deformation, and the deformation and stress of the upper is significantly greater than the stress and deformation of the bottom, which is more obvious that the Rayleigh waves along the ground depth is constantly attenuation of basic characteristics.