Bayesian Updating Model for Structural Vibration-Induced Hydrodynamic Added Mass of Rectangular Pile Cap Submerged in Water

This paper focuses on the calculation of the structural vibration-induced hydrodynamic added mass of the rectangular pile cap submerged in water. A total of 150 pile caps with different physical parameters are sampled by Latin hypercube sampling (LHS). The added mass coefficients of all the pile cap samples are computed using a three-dimensional (3D) potential-based numerical method. Based on the database of physical parameters and added mass coefficient results of the pile cap samples, the analytical model with Bayesian updating for the hydrodynamic added mass of the rectangular pile cap is proposed. The proposed model consists of a deterministic model and the additional correction terms accounting for the model inherent bias and model error. The formulation of the model is expressed as a function of a series of physical parameters of the pile cap. The unknown parameters in the proposed model are updated based on the produced database, and the formulation of the correction terms is optimized through a stepwise deletion process. The proposed model is then applied to calculate the hydrodynamic added mass according to the experimental modal testing setup of the isolated pile cap specimens and the group-pile cap foundation specimens submerged in water, respectively. Through the comparison between the modal results from the experiments and the proposed model, it is concluded that the proposed model can efficiently estimate the hydrodynamic added mass of a rectangular pile cap submerged in water with acceptable prediction error.