Research On Equilibrium Synergistic Method For Strengthening Design Of Prefabricated Multi-ribbed Beam Bridge

Above all of the highway bridges in our country, the number of small and medium span bridges occupies a large proportion, and in the construction of small and medium span bridges, prefabricated multi-ribbed beam bridge is the most widely used structural form. Due to the occurrence of damage and low design load grade, the early-stage construction of the In-service bridges are no longer adapt to the social reality that current traffic situation with increasing amount of heavy-load or overload vehicles, damaged bridge has greatly hindered the smooth transportation, become the bottleneck of the development of highway traffic. It is very important to study the maintenance and reinforcement of damaged bridges. While in the whole process of present strengthening design method for damage bridges, there is no quantitative evaluation of damage severity, lack of consideration in effect differences of component damage evaluation before and after the reinforcement.According to the current existing problems, this paper based on the current specifications for strengthening design of highway bridges, proposed a new method of prefabricated multi-ribbed beam bridge reinforcement design: "Equilibrium Synergistic Method for Strengthening Design". During the reinforcement design process, add the following parameters as the damage parameters to modify the load-bearing capacity limit equation which includes the load effect and structural resistance effect calculation: Section-reduction coefficient; Comprehensive modification coefficient of bridge load-bearing capacity; Deterioration coefficient of load-bearing capacity. Evaluate the structure condition by comparing the load-bearing capacity status of components. Guide the bridge maintenance and reinforcement by increasing the stiffness of components equally, minimize the cost of reinforcement to achieve the optimal improvement of the bearing capacity, thus, guarantee the security and durability of bridges after reinforcement.In order to analysis the superiority of this new method of reinforcement, this paper is based on a prefabricated bridge project, according to the bridge site testing and evaluation results, give a reinforcing designing scheme and establish the finite element models of the new method for strengthening design, innovatively introduced Pearson similarity algorithm to verify and validate the finite element model. The results show that comparing with the traditional method, the model of new method is more similar to the actual situation because of its’ Pearson similarity coefficient is closer to 1. The equilibrium synergistic method for strengthening design can effectively improve the overall load-bearing capacity of the bridge structure, which can serve as the references for other similar bridge reinforcement projects.