The Strengthening Design Optimization And Engineering Application Of 30 Meters Simply-supported Continuous Box Girder Bridge

The simply-supported growing continuous box girder bridge is a type of bridge which is widely used in our country, it has a good overall performance、small deformation、 good seismic performance, However, along with the increasing of vehicle number and weight, The damage and destruction of the bridge are increasingly serious, we need to repair, reinforce and reconstruct the bridge and renovation to improve the bearing capacity and service life of the bridge.The Paper based on the engineering of 30 meters simply supported continuous box girder bridge, through the appearance test of the old bridge and load test results to evaluate structural damage, determine the old beam strength reduction factor, calculate the bearing capacity of old beam. For the structure characteristics of 3×30m prestressed concrete simply supported continuous box girder bridge, three kinds of reinforcement scheme is proposed, we carries on the analysis comparison from the aspects of mechanical performance, technical performance and economic performance, and optimize the design of the traditional paste steel reinforcement technology, pasting steel plate unloading reinforcement technique is proposed.Paste the steel plate of reinforcement method is a relatively new reinforcement method, it is optimized based on the ordinary course of pasting steel plate reinforced method, put the traditional passive reinforcement into active reinforcement technology, the effect to improve the bearing capacity of bridges and the girder deformation and stress state is more noticeable, the reinforcement effect is superior to the ordinary pasting steel plate reinforced method. Through to the design of the paste steel’s concrete structure、construction method、key technology research, to provide technical support for its engineering applications and engineering application value.