Research on dynamic detection method of bridge vehicle load based on optimization algorithm

In recent years, accidents causing casualties and losses to people and property have occurred frequently throughout the country due to bridge safety problems, causing huge losses to the country and people’s property. To prevent the recurrence of such incidents and effectively maintain the safety and interests of the people, this paper intends to use the optimization algorithm as the technical support to study the optimal method for dynamic detection of vehicle loads on bridges. The gradient descent method is used to obtain the deflection influence line of the bridge dynamic test structure and the overall vibration frequency of the structure. The bridge test area is then selected by the stochastic gradient descent method, and the measured strain and deflection influence lines are used to modify the initial finite element model of the bridge so that the finite element model can truly reflect the actual mechanical behavior of the bridge structure. According to the survey, as of the end of 2019, there were 878,300 highway bridges with a total mileage of 6063.46 m, which was 26,800 more than in 2018, and the mileage increased by 4,948,600 m. Among them, mega bridges accounted for 5716 bridges with a mileage of 10,323,300 m, and bridges accounted for 108,344 bridges with a mileage of 29,237,500 m. Many bridges in service provide convenience for people’s life and travel but also bring great challenges to bridge management and maintenance, bridge appraisal, and assessment. Monitoring the bridge load condition helps to grasp the actual working condition of bridges in a timely and accurate manner and to warn and repair the safety hazards that appear on bridges in time to prevent accidents.