Research On The Assessment Methods Of Long-span Continuous Box Girder Highway Bridge Bearing Capacity

Due to the structural rigidity of continuous girder bridges, small deformation,compared with simply supported beam bridge, which greatly reduces the number of bridge expansion joints. In addition,it driving smoothly, good seismic performance,continuous girder bridge of this type are widely used in highway bridge bridge. But in recent years the phenomenon of frequent overloading, and become more serious every day. Overloaded to bridge caused many adverse effects, due to shock and vibration is too large cracks rapidly launch, over time, the cumulative damage will be greatly reduced carrying capacity of the bridge structure, shortening normal life,could easily lead to traffic accidents. Therefore, the carrying capacity of the bridge for fast accurate assessment is essential.In the thesis, take a long-span continuous box girder bridge as the research background, existing bridge assessment methods are analysised and comparied.First of all,establish Midas Civil build models based on static load test results to modify the model calculate the bearing capacity of the bridge as amended, and the estimated remaining carrying capacity. Comparative analysis based on the bearing capacity of the bridge inspection and specification is bearing capacity estimation results of the evaluation result and based on the load test. According to the results of the dynamic load test combined with model analysis of dynamic response and the modal parameters(frequency and vibration mode) to assess the bearing capacity of the bridge and determine the structure of the actual working condition, but also for the use of the original data accumulation phase structural assessment. Finally, the bridge health monitoring combined with the finite element analysis results.It provided security warning value and carried capacity assessment based health monitoring data.The research results show that the comprehensive existing bridge bearing capacity evaluation method for the long-span continuous box girder bridge is feasible for comparative analysis, and assess the mechanical properties of the bridge(including stiffness and load capacity) meet the specifications requirements, toprovide a reference basis for similar bridge projects, with the popularization and application value.