The Frequency Of Concrete Bridges Based On The Fracture Characteristics And Structure-based Performance Evaluation Technology And Its Applications

Now static test method to evaluate the structural nature of old bridges is very popular. Compared with static test method, the technique of assessment on load-carrying capacity of bridges has many advantages, such as simpleness, speediness, no-wear, acquired condition of test data is similar with running condition etc. But the method that dynamic parameter is directly used in quantitative assessment on load-carrying capacity of bridges is still miniature, and there has no unified standards of dynamic assessment technology. According to the experimental results which are obtained by dilapidated dynamic test on four pieces of RC simple T-beam, applied monadic nonlinear regression, a family of ~ a curves for equation that expresses the relation of stiffness ratio and frequency ratio for T-beam is obtained, and a relation for structural dynamic characteristics and bearing capacity of RC single beam is proposed in the article. Based on the measured basic frequency and crack characteristics, dynamic characteristic of the whole bridge is divided into single beam. By the application of research production for RC single beam model test it is met the aim is to evaluate structural characteristic of RC beam bridge. So the model of dynamic assessment is structural basic frequency and crack characteristic-rigidity-nominal ratio of reinforcement-resistance to bending of single beam. Combined with the research founding of the article, the software of dynamic assessment for the bearing capability of bridges. The program has friendly interface and is prone to use. Meanwhile, the program realizes automatization of check assessment for bridges. Finally, according to the dynamic assessment of nine typical RC simple bridges (five T-beam bridges and four plate girder bridges), the reliability and applicability of the analytical method and program in the article is verified.The research work pushes the use and spread of the dynamic assessment technology and it has provided theoretical and experimental bases for the development of the dynamic assessment technology.