Simplified calculation methods for earthquake-induced hydrodynamic added mass of immersed pile caps with different cross-sections

Abstract

Assessment of the earthquake-induced hydrodynamic added mass of pile caps is important in predicting the seismic resilience of deep-water bridges with an elevated pile group foundation. Simplified formulas for the hydrodynamic added mass of immersed pile caps with different cross-sections were derived in this paper. The added mass values of circular pile caps with various dimensions and submerged depths were estimated based on the numerical fluid-structure coupled model, and the corresponding added mass calculation formula was obtained through the curve fitting method. The formulas to determine the added mass for rectangular pile caps and rectangular pile caps with fillet or chamfer corners were further developed by incorporating the corresponding shape coefficients for the pile cap in the formula. A total of 200 pile caps with different cross-sections and physical parameters were selected using Latin hypercube sampling to assess the performance of the proposed formulas. Next, the consistency between these formulas and the numerical model for added mass results was observed. The proposed formulas are concise and enable efficient calculation of the hydrodynamic added mass of pile caps submerged in water.