Response of Sandy Bluffs to Random Wave Actions

This study investigates the recession of sandy coastal bluffs under random waves and changing water levels. A laboratory flume experiment was conducted in the wave flume at Stony Brook University using a sandy beach-bluff model subjected to waves and fluctuating surges. A laser-camera system monitored bluff profile evolution. Results showed rapid toe erosion and undercutting leading to major slope failures. Repeated wave impacts generated pore pressures, while toe erosion increased shear stresses, causing episodic collapses. Elevated pore pressures and lowered matric suction from wave run-up, and rising surges reduced stability. However, progressive toe erosion by waves was the most critical factor. The laser-camera technique effectively captured profile changes, revealing dynamics linking pore pressure fluctuations and bluff erosion from intermittent wave impacts.