A mathematical framework for efficient predictions of dynamic processes of RC piers under barge collisions

Abstract

The safety of bridge piers located in navigation waterways is often threatened by passing vessels nowadays. Empirical formulas such as those provided by AASHTO Guide Specification are currently extensively used to predict impact forces using equivalent static methods. However, the important dynamic effects involved in an impact event cannot be considered by a static analysis. Finite-element method is another strategy that is widely used in both engineering designs and scientific studies. Whilst finite-element method can well capture the main features involved in an impact event, it is expensive regarding both calculation time and computing resources. Simplified models are thus often needed to predict the dynamic impact processes efficiently. The coupled multi-degree-of-freedom model (CMM) proposed by the author previously is shown to be capable of predicting impact force time-histories and dynamic responses of pier columns efficiently with sufficient accuracy for a wide range of barge impact scenarios. However, empirical formulas for pre-estimating the values of the parameters introduced by CMM is still in great demand for practical applications. This paper aims to develop a mathematical framework enabling the computation of undetermined model parameters in terms of different input variables covering barge travelling information, barge bow stiffness and geometric information of an impacted pier column, and to thoroughly test the accuracy and efficiency of the proposed framework for realistic engineering applications pertaining to predictions of impact forces and dynamic response quantities of RC pier columns subjected to barge collisions.

Keywords

• Vessel impact
• Simplified models
• Empirical formulas
• Mathematical framework
• RC pier column