The effect of using embankments and stepped seawall as alternatives to reduce overtopping at Selatbaru Beach Bengkalis District
Zulkarnain, Oni Febriani, Lizar

POLITEKNIK NEGERI BENGKALIS

Abstract

Located in Selatbaru Village, about 25 km from the center of Bengkalis City, Selatbaru beach has become a favorite destination for tourists who want to enjoy the beauty of nature while engaging in outdoor activities. The current situation is during high tide and strong winds, waves run up the top of the seawall, causing seawater to surge onto the land. Therefore, it is necessary to conduct an analysis and simulation of the actual conditions using a prototype in the laboratory to determine whether adding an embankment would be sufficient the issue or whether an alternative, such as changing the slope of the seawall and adding an embankment, would be better. This way, the most effective method can be identified among these three alternatives.
This research will conduct experiments by creating a prototype based on field survey data and laboratory scale, including the seawall dimensions, water level, and wave height, with a scale ratio of 1:10. The experimental scenarios to be conducted in the laboratory a. Existing seawall slope of 1:3 with the addition of embankment, b. Changing the seawall slope to 1:5, and c. Changing the seawall slope to 1:5 with the addition of embankment. The irregular wave height to be simulated in the laboratory is 0.8 meters. The experiment will be conducted for 3 minutes to observe the response of the seawall structure to incoming waves and the overtopping occurring on the seawall structure.
The results shows that the alternative of adding an embankment and using a 1:3 seawall slope, as per field conditions, has already been able to reduce overtopping. Therefore, the second and third alternatives do not need to be implemented, as the first alternative has already reduced overtopping by 40 percent. Thus, the first alternative, which involves adding embankment without changing the slope of the structure, is already sufficient to mitigate the impact of overtopping.

Keywords: stepped seawall-waves run up- overtopping-embankments

Topic: Natural resources management