Research On Load Capacity Of Sub-health Beam Bridge

In our country,the number of sub-healthy bridges is very huge.Some bridges work in spite of illness for a long time due to the poor management,some other bridges have been in the state of overloading belong to working load exceeding the design value,and another bridges are excessive treated by the defects of evaluation system.Therefore,How to use the sub-health bridges reasonably and safety,which will directly affect the normal operation of the traffic network in our country.In order to evaluate the technical status of the bridge more effectively,and to use the sub-health bridge effectively,this paper presents a more operable method of evaluation for sub-health beam bridge based on the innovative way of thinking and the changing factors of the load and resistance.Specific contents are as follows.This paper analyzes the types and causes of the typical disease for beam bridge.According to the content of the limit state in the current code and the data of static and dynamical load test,the current load capacity and load limit of the bridge are evaluated in a new method by using the strain,deflection,frequency and the crack.The availability of the new method was verified by a practical engineering.In a typical beam bridge as an example,based on the data of bridge health monitoring system(BHMS)calculate the decreasing trend of resistance of structure and the increasing trend of load effect due to the ascending traffic volume,in order to estimate the remaining life of the beam bridge.