Performance evaluation of modular bridge girders using simplified load simulation techniques

Modular bridge girders are increasingly adopted to accelerate construction, reduce site disruption, and enable standardized quality control in short- and medium-span bridges. Despite their advantages, reliable evaluation of structural performance remains challenging when full-scale testing or advanced numerical modeling is impractical. This research presents a performance evaluation framework for modular bridge girders using simplified load simulation techniques that approximate critical service and ultimate limit state responses. The approach combines idealized load patterns representing vehicular, pedestrian, and environmental actions with analytical beam models calibrated to modular connection behavior. Key performance indicators include deflection profiles, stress distribution, load sharing efficiency, and reserve capacity under combined loading scenarios. The proposed methodology emphasizes computational efficiency while retaining sufficient accuracy for preliminary design verification and comparative assessment of girder configurations. Parametric simulations are conducted to examine the influence of span length, modular joint stiffness, girder spacing, and load placement on global and local responses. Results demonstrate that simplified load simulations can capture governing trends in flexural demand and serviceability performance, provided that connection flexibility is explicitly represented. The research further identifies critical thresholds beyond which simplified assumptions may underestimate localized stresses near modular joints. By bridging the gap between overly conservative hand calculations and resource-intensive finite element models, the framework supports informed decision-making during early-stage design and rapid evaluation of alternative modular layouts. The findings contribute practical guidance for engineers seeking efficient yet rational tools to assess modular bridge girder performance, enhance constructability, and ensure structural safety within constrained project timelines and budgets. Moreover, the framework facilitates transparent communication of assumptions, supports preliminary risk screening, and enables consistent benchmarking across projects, thereby assisting designers, reviewers, and stakeholders in selecting modular girder solutions that balance performance, economy, durability, and adaptability under varying regulatory and site constraints encountered during accelerated delivery programs and multidisciplinary coordination efforts globally.