Research On Strengthening Method Of The Upper Structure Of The Plate Beam

In recent years, the traffic development under the guidance of the theory of bridge construction level in rapid development scale and speed of a shocked the world, and made great achievements. During this period,Jilin province built a large number of highway bridges. More than 80% of the upper structure are medium and small span Bridges, including plate girder structure for more than 70%. Due to the old design of the bridge load, nowadays a lot of old bridges ware seriously damaged. The bridges have been in the “bad” working condition, such as insufficient intensity, low durability and safety hidden trouble. In Europe and the United States and other developed countries, the newly built bridge has gradually reduce, the most bridge have entered the aging period. The bridge construction has been transferred to the maintenance of Bridges. The study of these dangerous bridge has become a widely attention important topic betweenthe engineers. All countries in the world extend the lifespan of the bridge, to ensure the safety of its use and the reliability as its important role in the construction of the bridge. Bridge reinforcement can not only save a lot of human, material and money, but also guarantee the bridge operation, as well as the protection of the existing environment. Bridge reinforcement costs generally about the newly built bridges of the 15 ~ 25%, and can greatly shorten the construction cycle. Therefore, the research of Jilin province highway upper structure of the plate beam reinforcement methods can improve the service level of highway Bridges and the reinforcement of similar bridge upper structure level, It will inevitably produce a great social benefit and economic benefit in the near future.This paper studied the external prestressed strengthening technique and the reinforcing for increasing cross-section reinforcement technology method, mainly for Jilin province highway(Changchun to Siping and Changchun to Jilin) upper beam characteristics. The purpose of the upper structure reinforcement design is to provide a relatively reasonable and effective suggestions. The research content mainly includes:First, according to the statistics and analysis of girder bridge upper structure form and technical conditions, we can grasp plate girder main disease and use conditions of the upper structure and conduct technical condition evaluation of the upper plate girder structure.Secondly, using the new and old standards to calculate the upper plate girder structure bearing capacity and load test related stress analysis, aiming to assess the use condition of Jilin province highway(Changchun to Siping and Changchun to Jilin) upper beams.Thirdly, using the external prestressed strengthening technique and the reinforcing for increasing cross-section reinforcement technology method to reinforce the upper plate girder structure.and evaluating characteristics and applicable conditions of two kinds of strengthening methods. According to the condition of the 13 m span prestressed concrete slabs(Changchun to Siping expressway), theoretical analysis and research shoud be used to determine the strengthening plan.Finally, considering structure requirements, the feasibility of strengthening construction and engineering cost and other factors, the Jilin province highway upper plate girder structure should be analysed to de determine the suitable strengthening plan. Only in this way, the service level of Jilin province highway bridges and the similar bridge upper structure level can be improved.