Performance evaluation of damaged corrugated soil–metal bridges strengthened with CFRP patches

Many steel infrastructure systems, such as corrugated soil metal bridges (SMBs), were installed decades ago and have reached the end of their service life, primarily due to corrosion from the surrounding environment and/or mechanical abrasion. To extend their serviceability and enhance their load-bearing capacity, various rehabilitation techniques have been developed. This study investigates the structural performance of a buried arch-shaped corrugated SMB subjected to surface static loading through large-scale laboratory experiments on three configurations: intact, deteriorated, and rehabilitated bridges. A new rehabilitation technique was implemented in which carbon fiber reinforced polymer (CFRP) patches were internally applied to damaged regions of a corrugated SMB, marking one of the first full-scale investigations of CFRP use for strengthening buried corrugated SMBs under surface static loading. CFRP composites offer several advantages for repairing metal structures, including corrosion resistance, high strength-to-weight ratio, and favourable mechanical properties, which collectively improve strength, stiffness, durability, and load-bearing capacity. As an example of the observed improvements, the internal stresses at the SMB crown in the CFRP-rehabilitated configuration were reduced by approximately 29 %, accompanied by reductions of about 25 % in vertical crown deformation and 23 % in surface settlement relative to the damaged configuration. Complementary three-dimensional finite element (FE) models were developed to simulate the SMB response under static surface loading. The numerical results were validated against experimental measurements, confirming the ability of the FE models to capture the behaviour of intact, deteriorated, and rehabilitated SMBs. The validated models were then employed to study three additional damage scenarios, both before and after rehabilitation with CFRP patches, thereby demonstrating the effectiveness of CFRP in mitigating performance deterioration caused by the bridge damage. • Soil-structure interaction of flexible corrugated metal bridges. • Rehabilitation of deteriorated corrugated soil metal bridges. • Large-scale laboratory experiments on three configurations: intact, deteriorated, and rehabilitated bridges. • Rehabilitation was carried out using carbon fiber reinforced polymer (CFRP) patches applied to damaged areas inside the bridge