The Research Of Evaluation Method Of Bridge Load-Bearing Capacity Based On Correcting Finite Element Model Using The Influence Line

The method of bridge evaluation based on correcting finite element model is a combination of experiment and theoretical model, it can get a model similar to the actual structure, which can be used to evaluate the load-bearing capacity well. Influence line contains large amount of data and can be got quickly, so this paper studied two evaluation methods of load-bearing capacity of bridge based on correcting finite element model using the influence line. The two methods both need to correct the finite element model based on strain influence line at first, then use different ways to evaluate load-bearing capacity of bridge, one is using the corrected results to calculate load-bearing capacity based on the design code, the other is carrying out load test on the corrected model. The two methods were used in a newly-built prestressed concrete continuous box girder bridge to study their feasibility and reliability, the main work of this paper is listed as followed.1. A test was conducted on the test bridge to acquire the strain influence lines of the main points, they were acquired by using the test system to record the relationship between strain and load position when a car was moved along the specified path in the bridge.2. The theoretical strain influence lines were calculated by the finite element model of the bridge established by ANSYS, they were compared with the measured values, then the model was corrected with the help of parameter identification and calibration function to make the model represent the actual working condition of the bridge.3. The corrected results were used to calculate the load-bearing capacity of the test bridge based on the design code, which includes the calculation of load-bearing capacity limit state and the calculation of service ability limit state. Computation parameters in this method are corrected by test data, so it has high reliability.4. Traditional load test was carried out on the test bridge to get a calibration coefficient. Simulation load test was carried out on the corrected model to get a calibration coefficient, it was compared with the results from traditional load test, which proved the feasibility and reliability of simulation load test.