Study On The Carrying Capacity Of Small And Medium-span Bridges Based On The Overload Transportation

Overloaded vehicles with large dimension and large dead weight, number of single axle load and wheel much, can cause structural damage of the bridges. With the increasing number of the overload transportation, rule over the management is constantly evolving, but have not yet come up with effective governance approach. Therefore, the study on the carrying capacity of small and medium-span bridges based on the overload transportation has the important theory and the practical significance.Based on previous researches of overloaded vehicles and small and medium-span bridges, this paper relying on WenYuan highway engineering acquired technical parameters of the overloaded vehicles, determined the typical overload vehicle models, used the method of generation and actual load calculation, such as load calculation of medium and small span bridge bearing capacity, and established the medium and small span bridge models which used the finite element analysis software MIDAS/Civil, compared and analyzed the load effect. The concrete work is as follows:1. First, this article discussed the present situation of the overloading transportation, pointed out the danger to the upper structure of the medium and small span bridges, refered to the overloading transportation management present situation at home and abroad. As a result, it was necessity to study on the carrying capacity of small and medium-span bridges based on the overload transportation.2. This paper introduced the load-bearing potential of small and medium span bridges, and presented the affecting factor of bearing capacity.And then it expounded in detail valuation method of bearing capacity.3. In the paper, the author collected technical parameters of the overload transportation, found out the load model of the typical six axis, seven axis overrun vehicle.4. The appropriate method for assessing the carrying capacity of the bridge has been selected. Using the structure principle, the paper calculated bearing capacity of small and medium span bridges based on the overload transportation.5. The author simulated models of the small and medium-span bridges, analyzed the calculation results, and confirmed the reliability that overloaded vehicles can pass small and medium span Bridges.6. The results in the paper are valuable for establishing system procedures of the overloaded vehicles,and realizing the systematic management.