STRUCTURAL INTEGRITY ASSESSMENT OF COASTAL JETTIES

This study presents a comprehensive structural integrity assessment of coastal jetties, focusing on their current condition, safety, and serviceability. A convergent parallel mixed-methods design integrated non-destructive testing (NDT), visual inspection, stakeholder interviews and geotechnical observations across three representative jetties (coded Jetty A, Jetty B, and Jetty C). Quantitative analyses benchmarked against BS 6349, BS 8110, and Eurocodes show performance deficits of 30–60% relative to recommended thresholds. Jetty A exhibited mean in-situ compressive strengths of 10.5–13.6 N/mm², far below marine concrete benchmarks, with reinforcement corrosion and extensive spalling indicating severe capacity loss. Jetty B recorded up to 35% steel section loss in sheet piles and residual thicknesses <60% in critical zones, alongside subsidence and voids under the slab. Jetty C showed relatively adequate concrete strengths (30–46 N/mm²) but suffered localized wall collapse driven by geotechnical instability and construction defects. Overall, 72% of assessed elements failed at least one benchmark criterion. The study recommends full reconstruction for Jetty A and failed stretches at Jetty C, targeted steel rehabilitation and soil stabilization at Jetty B, and institutionalization of preventive maintenance and continuous structural health monitoring across all coastal jetties.