Lateral dynamic responses of coastal group piles considering pile‒water‒soil interactions

Abstract

In this paper, an analytical framework is developed to investigate the dynamic impedance of pile groups comprising an arbitrary number of cylindrical piles connected with a rigid cap. The solution considers the combination of the secondary ground wave effects transferred by the pile‒soil vibration and the hydrodynamic pressure from the pile‒water interaction. A displacement attenuation function is introduced to define the pile‒to‒pile interaction factor, which describes the relationship between the active and passive piles based on the soil reaction development. The pile is modeled as a Euler‒Bernoulli (EB) beam, and the hydrodynamic pressure is calculated using radiation wave theory. Biot's dynamic poroelastic theory describes the saturated soil around the piles. The rationality and correctness of the proposed theoretical model are verified by degenerating the solution to the existing research results. An extensive parametric analysis is conducted to investigate the effect of various factors on the lateral dynamic impedance of the group pile. Moreover, some interesting findings and meaningful conclusions are obtained.