Study On The Calculation Method Of Strengthening Bridge Compression Member By Enlarging Section

With the development of China's economic construction,highway traffic volume is increasingly high,among which,a considerable part of the early construction of concrete Bridges are facing the problem of insufficient bearing capacity,strengthening the bridge structure has gradually become one of the main tasks of bridge management.There are many ways to strengthen Bridges.The method of increasing section of concrete is one of the most commonly used methods.However,there is still a lack of reliable and convenient method to calculate the bearing capacity of strengthened members.In view of the existing problems in the existing standard formula,this paper adopts the method of combining numerical analysis,model test and theoretical analysis to study the calculation method of the bearing capacity of the normal section of existing members strengthened by increasing the section under the state of initial stress,mainly aiming at the axial compression member of concrete.The main contents include:1.Through theoretical analysis,this paper discusses the existing problems of formulas in the current norms,analyzes the influence of relevant parameters according to the existing problems,and uses the finite element method to simulate and analyze the bearing capacity of the axial compression column of concrete with increasing section reinforcement,and determines the value of the relevant parameters.2.The model test of reinforced section reinforcement of concrete axial compression column was carried out,and different concrete column specimens were made by considering the stress level index in the experiment.The initial load of different stress level indexes is applied to the original member by welding pressure of steel plate and bolt,and then it is strengthened,and the positive section bearing capacity of the concrete axial compression column is measured by axial pressure test to increase the cross section reinforcement.3.According to the model test of increasing cross section reinforcement of concrete axial pressure column,the equivalent finite element model is established,the calculation results of finite element model under different parameters are compared and analyzed,and compared with the test results of reinforced concrete axial compression column with increasing cross section,the correctness of each other is verified.4.On the basis of theoretical analysis and model test verification,a method for calculating the bearing capacity of the reinforced section of concrete axial compression column is established.