Dynamic stability analysis of pile groups under wave load

Abstract

As marine resources have been exploited in recent years, the number of offshore buildings has greatly increased. Foundations of these buildings are mainly pile and pile group foundations. Compared with the single pile, the interaction between piles in the pile group is more complicated. The dynamic stability analysis of pile groups under wave load has not been reported thus far. On this basis, based on the theory of diffraction, the modified Vlasov foundation model and the principle of dynamics, the high-order vibration differential equation is obtained. The interaction factor method and transfer matrix method are combined to establish dynamic stability equations of the active pile and passive pile. The dynamic interaction factor between piles and the group pile impedance are obtained. Parametric analysis is carried out. The ratio of the pile spacing to the pile diameter S/Dis found to be the major factor in pile group dynamic interaction. As for the pile group, the displacement of the pile u increases with increasing wave height Hlinearly and increases with increasing wavelength Lnonlinearly, both increments are much lesser than that of the single pile. the topsoil is of vital importance to the pile group impedance. In engineering practice, the pile group stability can be improved by increasing Young's modulus of the topsoil.