Wave interaction of vertical seawalls fronted by shingle beaches

Investigating how waves interact with vertical walls when a mobile shingle beach is present in front of them

Wave interaction of vertical seawalls fronted by shingle beaches

Investigating how waves interact with vertical walls when a mobile shingle beach is present in front of them

Overview

Coastal communities increasingly rely on vertical seawalls for protection, yet many of these structures are fronted by dynamic shingle beaches that constantly reshape under wave action. This project investigates how waves interact with vertical walls when a mobile shingle beach is present in front of them.

Through physical modelling in our COAST laboratory and advanced data analysis, the research examines wave overtopping, wave forces, and beach profile evolution.

The aim is to improve prediction methods and provide more reliable guidance for coastal defence design under changing sea levels and storm conditions.

Objectives

Quantify wave overtopping at vertical walls fronted by shingle beaches under irregular wave conditions

Investigate how beach morphology influences wave loading and overtopping discharge

Evaluate and refine existing design guidance (e.g. EurOtop formulations) for composite coastal structures

Develop improved empirical relationships and reduction factors for engineering applications

Provide practical recommendations for safer and more resilient coastal infrastructure design.

Context of the issue

Many coastal towns rely on vertical seawalls for flood and erosion protection. However, these structures are often built in front of shingle beaches that are highly dynamic and respond rapidly to storms, tides, and changing sea levels. During extreme events, beach levels can lower significantly, increasing wave loading and overtopping at the wall.

Existing design guidance largely treats the structure and the beach separately, which can lead to uncertainty in predicting overtopping and structural forces. With rising sea levels and more intense storm patterns, improving the understanding of this combined wave–beach–structure interaction is critical for resilient coastal infrastructure.

How the project addresses the issue

This project combines physical modelling, detailed instrumentation, and advanced data analysis to investigate wave interaction with vertical seawalls fronted by mobile shingle beaches.

By systematically testing irregular wave conditions and varying beach profiles in the COAST Laboratory, the research quantifies overtopping discharge, wave forces, and beach evolution.

The results are used to evaluate and refine existing engineering prediction methods, helping to reduce uncertainty in coastal defence design. Ultimately, the project contributes towards more reliable, climate-resilient design approaches for composite coastal structures.

Centre for Coastal and Ocean Processes and Engineering (C-COPE)

C-COPE brings together strength areas from across the University's Faculty of Science and Engineering with a research focus on the physical and chemical processes in coastal, ocean and marine environments, and their human impacts.

The Centre's sphere of interest stretches from the head of tidal estuaries to the bottom of the ocean, and includes the disciplines of physical oceanography, marine biogeochemistry, coastal engineering and marine geology.