Structural evaluation through load testing, coupled with advanced Finite Element Analysis (FEA), is a powerful tool to load rate posted bridges with the aim of removing the current posting. Based on SDR’s vast experience in structural evaluation and load testing, bridges can carry much higher loads than those estimated by design code equations. Load testing captures actual behavior of the structure (load distribution) and accounts for strength enhancing factors not included in design.
The LA 182 bridge over Berwick Bay is controlled by reinforced concrete T-beam spans. SDR was tasked with performing structural evaluation though load testing of the T-beam spans with the aim of removing the current posting.Test results, along with the FEA, revealed that, due to the support conditions of the slab, partial fixed end moments were developed, causing significant reduction in mid-span moment compared to moment calculated assuming simple-beam action. Load rating of the bridge was carried out in light of the testing findings and FEA results, resulting in an increase of load rating factor from 0.85 to 1.23.