Evaluation of the Hydraulic Performance of a Rear-Parapet Vertical Breakwater under Regular Waves through Hydraulic Experiments

Byeong Wook Lee,Woo-Sun Park

doi:10.3390/w12092428

Byeong Wook Lee, Woo-Sun Park

Open Access

https://doi.org/10.3390/w12092428

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Abstract

Climate change has resulted in increased intensity and frequency of typhoons and storm surges. Accordingly, attention has been paid to securing the breakwater’s stability to protect the safety of the port. Herein, hydraulic model experiments were conducted to evaluate the hydraulic performance of a vertical breakwater having a rear parapet. For comparison, cases in which the parapet was placed on the seaside, the harborside, and at the center of the breakwater were considered. Regular waves were used for convenient performance analysis. Five wave gauges and nine pressure transducers were installed to secure physical data for hydraulic performance evaluation. Results showed that a rear parapet can reduce the maximum wave force acting on the breakwater. Even though impulsive pressure was generated, it did not affect the stability of the breakwater owing to the phase difference between the maximum wave pressures acting on the caisson and parapet. By decreasing the maximum wave force, the required self-weight that satisfies the safety factor of 1.2 was reduced by up to 82.7%; the maximum bearing pressure was reduced by up to 47.6% compared with that of the parapet located on the seaside. Thus, the rear parapet was found to be more suitable for actual applications.

Highlights

Because of the increases in sea temperature and level due to global warming, typhoon intensities and storm surge heights have increased in recent years [1,2,3]
3) are sufficiently low to be ignored of the phase difference between the wave pressures when the average total wave force is maximum. These results indicate that the rear-parapet can be used as an alternative to reducing the maximum wave force
The effects of the installation position of a parapet on a vertical breakwater were investigated through hydraulic experiments with regular waves in a wave channel

Summary

Introduction

Because of the increases in sea temperature and level due to global warming, typhoon intensities and storm surge heights have increased in recent years [1,2,3]. Harbor cities and facilities are more vulnerable to such events, making it necessary to establish countermeasures for harbors, including hinterland cities. The reinforced harbor structure was once again damaged by high waves because a large typhoon exceeded wave height of the design [4,5,6]. To ensure the safety of the harbor from such environmental changes, it is necessary to maintain the stability of the main breakwater installed at the harbor mouth to prevent waves propagating from the open sea to the harbor. Various studies have been conducted to respond effectively to wave overtopping by increasing the design wave height [7,8,9,10] and utilizing the wave energy corresponding to wave overtopping [11]

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