关键词: Fredholm积分方程, 排桩, 被动隔振, 移动荷载, 饱和土, Biot理论

Abstract:

Following Muki and Sternberg’s method, the passive isolation of vibration due to moving loads using pile rows embedded in a poroelastic half space is investigated. The responses of the poroelastic half space is governed by Biot’s theory, while the pile is described by the 1D bar vibration theory. Using the free field solution for a moving load applied on the surface of a poroelastic half space and the fundamental solution for a harmonic circular patch load applied to the poroelastic half space, the second kind of Fredholm integral equations in the frequency domain describing the dynamic interaction between pile rows and the poroelastic half space is developed. The time domain responses for the pile-soil system can be obtained by using IFFT arithmetic, then, the isolation vertical vibration effectiveness is obtained. Comparison of our results with some known results shows that our results are in a good agreement with existing ones. Numerical results of this study show that velocity of moving loads has an important impact on the vibration isolation effect of pile rows. The same pile row has a better vibration isolation effect for the lower speed moving loads than for the higher speed ones. Also, the optimal length of piles for higher speed moving loads is shorter than that for lower speed moving loads.

Key words: Fredholm integral equation, pile rows, passive vibration isolation, moving loads, poroelastic half space, Biot’s theory