Study For Technical Condition And Bearing Capacity Evaluation Of Swivel No.1 Bridge In Dinglong Road After Reinforcement

The swivel No. 1 bridge in Dinglong road is located in the provincial highway 209 line, the bridge length 103.2 metres, main span is truss arch bridge, the construction of swivel technology, lower structure is gravity abutment, using C15 concrete, foundation for the two steps of rubble concrete foundation, arch foot reinforced concrete pile column foundation. The original design of the bridge for the steam is car-20 and Trailer-100, by taking a series of measures after the reinforcement,design load is highway-II. The bridge Foundation sinking resulting in negative bending moment increases, upper chord longeron longeron edge cracks on the serious, long-term operation state, the bridge structure cracks, the bridge deck is damaged, railings and expansion joint damage, some vehicles, especially big coal overweight vehicles on the bridge of overload, partial load, cause the stress of the bridge serious imbalances, horizontal connections has weakened.To solve these problems, we adopted a series of maintenance and reinforcement measures, which mainly using the reinforced method of pasting steel plate and steel box girder.The researching object of this paper is swivel No. 1 bridge in Dinglong road after reinforcement. We evaluated technical condition of this bridge after reinforcement, checked floor system and the structure of the upper and lower structure components, and according to the results of the inspection,technical condition was evaluated through evaluation procedures of member,component,structure and overall bridge.Space finite element model was established through the load test, under various conditions, purpose is to test the bridge strain and isplacement and natural frequency and damping ratio of the control section, compared with the measured results; through calculating the internal force of the section Bridge structure before and after the reinforcement,compared and analysed the bearing capacity of the arch rib, thus to evaluate the bridge bearing capacity and judge the performance of the bridge.According to “Standards for Technical Condition Evaluation of Highway Bridges”, this paper evaluate technical condition of bridge after reinforcement,the result is that the overall technical condition evaluation scale is evaluated level 1, the effect of reinforcement meets the requirements, and the appearance quality meets the requirements. According to “Specification for Inspection and Evaluation of Load-bearing Capacity of Highway Bridges”, we evaluate bearing capacity of bridge after reinforcement, and the result is that bridge structure strength meet the requirements, the static stiffness meet the requirements, the structure is close to the flexible working conditions, the horizontal and vertical dynamic stiffness can meet the requirements, and the bearing capacity has improved significantly.