Reliability-based Vehicle Weight Limit for Small- to Medium-span Simply-supported RC Bridges

Heavy transportation may affect the serviceability of existing reinforced concrete (RC) beam and slab bridges. To investigate the vehicle weight limit (VWL) for the existing simply-supported RC beam and slab bridges in South China, a reliability-based analysis method was first established. Second, the vehicle load and wheelbase characteristics were analyzed based on the weigh-in-motion (WIM) data. The probability model of six-axle heavy vehicles in South China was determined, based on which a database including 10,000 samples of heavy vehicles was randomly generated using the Monte-Carlo simulation. Third, the concept of effective axle loads and wheelbases was proposed and a MATLAB program was developed to analyze the flexural response caused by effective axle loads and wheelbases. Finally, the VWL for the small- to medium-span simply-supported RC beam and slab bridges was determined by comparing the reliability index of each heavy vehicle to the target reliability index. The VWL proposed in this study can supplement the examination and approval systems for heavy vehicles to pass through small- to medium-span simply-supported RC bridges.