Damage Analysis And Reinforcement Design Of Prestressed Concrete Small Box Girderbridge

As China’s "one belt,one road" strategy is implemented,the domestic transportation construction is also more vigorous development.Under the background,China has been striding forward steadily from " bridge-construction country" to "great bridge power".The prestressed concrete small box girder structure,as one of the important forms of bridge construction,has also been very rapid development and extensive application in recent years.Prestressed concrete small box girder is simple in structure and fast in construction,but due to improper construction,overload of vehicles or inadequate maintenance in later stage and other factors,it is easy to appear various bridge diseases.Therefore,it is very important to sort out and analyze the disease of this type of bridge and put forward reasonable and effective reinforcement methods.In this paper,two prestressed concrete small box girder bridges are taken as an example.Based on the appearance inspection and load test results of the bridge,the disease and current situation of the bridge are evaluated,and the disease grade of the two bridges is grade IV.Based on the code for the inspection and evaluation of the bearing capacity of bridges,the bearing capacity and working state of the two bridges are evaluated,the reduction of resistance effect of the two bridges is 0.848 and 0.879 respectively.As the status of the two bridges does not meet the effect causing by existing load that strengthening measures need to be taken for the bridge.In view of the failure of the continuous structure between the couplets of bridge,it is reinforced taking a simply supported bridge.By comparing the strengthening effect and economic benefit of the two methods,the reinforcement method of sticking carbon fiber is recommended.For the bridge with failure of transverse connection,in order to avoid the damage of single beam,it is reinforced mainly by adding diaphragm and laying bridge deck to increase the overall transverse rigidity of the bridge.Through calculation and comparative analysis of the reinforcement effect,it is recommended to lay a new bridge deck for reinforcement.