Development Of A Management System For Evaluating Permit Requests Of Vehicular Overloads On Highway Bridges

With the rapid development of the national economy, the circulation of very heavy trucks has become more and more common. In China, the management of these overloaded vehicles is still on a dispersed, local, empirical and non-automated stage, the procedure of the permit checking of vehicular overloads is time and cost-consuming. As a crucial component, Bridges in a highway network affect the circulation of vehicular overloads a lot. The higway authorities always need to conduct summary structural safety evaluations for most of the bridges involved, which leads to the ultimate decision. Furthermore, in some cases where permission is granted, several bridges have to be monitored or strengthened during trcuck passage. To shorten the average decision period, this paper presents an entire process of the development of a management system, which aims to evaluate the permit requests of vehicular overloads on highway bridges. The main research work of this thesis can be summarized as follows:(1) Detailed introduction of the method used during the process of permit checking of vehicular overloads, which can be referred as'Comparison of internal forces', are offered. And the accuracy of the permit checking modulus of the management system is verified.(2) A simplified method for determing live load distribution factors for degign load vehicles and overweight vehicles is provided, the empirical formulas provided by which can achieve live load distribution factors of the slab bridges and the T-shaped girder bridges.(3) Dynamic models of the vehicle-bridge interaction is established, meanwhile, its numerical solution is obtained. And the effect of the five factors towards the dynamic response of the simple-supported beams are studied, which includes the initial conditions, the velocity, and the weight of the overweight vehicles, the roughness of the bridge deck and the vertical flexible stiffness of the girder. Futhermore, the impact factors of the vehicular overloads are calculated and compared with the values computed according to the national design code, finally, some valuable advices are provided for the regulation of the heavy trucks when they cross the bridges involved.(4) A management system for evaluating permit requests of vehicular overloads on highway bridges are successfully developed, which turns to be robust and allows for prompt, economical, and safe decision making on permit checking of vehicular overloads.