The Analysis On Reliability And Load-carrying Capacity Of The Existing Prestressed Concrete Bridge

Bridge is the throat hub of the city roads, highways, railway lines. It plays an important role in the construction of the national economy. However, almost all of these bridges have some damage because of design, construction, deterioration of material, environment and many other factors. There are some bridges which are designed according to lower designing grade. These bridges have more and more problems of safety along with the advancement of the highway development which resulting in structural strength, stiffness and durability lower and the operating conditions can not meet the needs of society. Based on the investigation, it is to research the degree of deterioration, the potential capacity of load-carrying, the degree of reliability and etc.Using previous research conclusions as references, It analyzed the result of the experimental research on site, analyzed the behaviors by nonlinear spatial finite element method, evaluated the reliability of load-bearing capacity and so on. Then, the effective maintenance and reinforcement can be carried through. The main content and results of this dissertation are as follows:1. Many aspects have been done in the experiment, such as bridge viewing examination, nondestructive detection, static test, dynamic test and so on. A comprehensive assessment about the carrying capacity of the bridge was given.2. Dongfeng Bridge was analyzed under the testing load by nonlinear spatial entity finite element method. The analysis results were compared with the test. The applicability of the analysis method was proved. Some parameters which affect the load-carrying capacity and deflection of concrete bridge were analyzed and compared. Tried to establish the finite element model based on the actual situation.3. The modified method on dead load and vehicles load were discussed based on the character of the load on the concrete bridges. Probability model at present was discussed considering the time-dependent of resisting force of concrete bridge. After completing resistance and load models, the limit state equations of carrying capacity of bridges damaged are formulated. The reliability theory is integrated with the evaluation of bridge structures. As the resistance is time-dependent and the vehicle load is non-normal in these equations, the reliability of Dongfeng Bridge was analyzed.