Experimental and numerical investigation of the dynamic response of reinforced concrete piles under underwater explosion-induced wave loading

A series of underwater explosion experiments were conducted, where the morphological characteristics of explosion-induced water mounds were recorded, and the relationships between underwater explosion-induced wave loading (UEWL) and key explosion test parameters were analyzed. This study aimed to examine the damage characteristics of reinforced concrete (RC) piles subjected to underwater explosion-induced waves (UEIWs). First, a numerical model of UEIWs was developed using the Structured Arbitrary Lagrangian–Eulerian algorithm in LS-DYNA finite element software and validated by experimental data. Additionally, numerical models of underwater explosions were developed for both rigid cylindrical piles and RC cylindrical piles to analyze the distribution of UEWL around these structures. This study further investigates the dynamic response and failure characteristics of RC piles subjected to UEWL. The results indicate that wave impact on cylindrical piles is most significant at a dimensionless distance of 0.77. Compared with displacements induced by shock waves and bubble pulsation, those caused by UEWL accounted for only 5% and 1.8% at the mid-span, and 10.8% and 5.3% at the air–water interface, respectively. These results demonstrate that UEWL can still inflict noticeable secondary damage on RC piles, which is critical for the structural safety of high-pile wharves.