Enhancing tsunami resilience for coastal bridge piers through seawall-integrated breakwaters: An experimental study

Abstract

In ocean engineering, breakwater plays a crucial role in protecting coastal structures such as bridge pier from the impact of extreme sea waves. However, enhancing the existing breakwaters' ability to withstand extreme wave remains an urgent issue to address. This study explores the reinforcement strategy of breakwater against extreme sea waves by installing seawalls on the breakwater. Utilizing dam-break wave generation techniques to simulate tsunamis, the study experimentally evaluates the effectiveness of seawalls in reducing the tsunami forces exerted on bridge pier model and numerically investigates the tsunami forces on the seawalls. The focus of this research is to analyze the pressure distribution on seawalls and the impact of different seawall configurations on the reduction of tsunami forces on bridge pier model. Results show that: Under the tested wave condition (a) The height of the seawall on the breakwater is a critical parameter, as increasing wall height reduces the tsunami forces exerted on the bridge pier behind it. The taller seawalls are subjected to greater tsunami forces in tested cases; (b) The trend of extreme pressure values for different seawalls starts increasing at the bottom and then decreases; (c) There is a critical distance that the breakwater being most effective at reducing tsunami impact forces between the bridge pier model and the breakwater. This study not only deepens the understanding of the interaction between tsunami waves and seawalls but also offers practical guidance for designing structures with disaster resilience, significantly influencing the future design and construction of tsunami-resistant coastal infrastructure.