Assessment Of Bearing Capacity Of Exiting Reinforced Concrete Ribbed Arch Bridge And Study On Its Strengthening

Reinforced concrete arch bridges have been widely used in the bridge engineering, especially in the highway bridge engineering. As time goes by, the structural materials will age and deteriorate gradually, leading to degradation of the material properties, as a consequence of the influence of the climate and the environmental factors. Moreover, considering the factors of improper design, poor quality construction and the development of vehicle load etc., a lot of existing bridges have been damaged over the days, and their bearing capacity is reduced, durability is missed, and then influence their safe service seriously. So, these bridges need to be maintained or strengthened in time to eliminate the hidden danger.This thesis reviewed the research results about the bridge bearing capacity assessment and strengthening at home and abroad firstly. Then by taking the Guang'an Baita Bridge as the engineering background, the appearance detection, the static and dynamic load test, the bearing capacity assessment, the strengthening method, as well as the performance reassessment after the strengthening of the existing reinforced concrete arch bridges are further discussed. The main contents are as follows.1. Summarize the typical damages of the concrete reinforced ribbed arch bridges, and analyze the causes.2. Appearance detection and primary evaluation. By adopting proper detecting method, the defects and material performance of the main load-bearing component of the bridge were obtained, as well as the arch axis of coordinates. Then, the primary evaluation of the bridge was implemented according to the detecting results.3. Static and dynamic load test. Use the finite element method to obtain the static and dynamic analysis, including the force calculation, vibration characteristics and stability. On the other hand, compare the results of static and dynamic load test to evaluate the static and dynamic performance in service.4. Bearing capacity assessment. According to the appearance detection and static and dynamic test results, modifying the material performance, the arch axis of coordinates and the impact factor of the assessment model, and then using the modified model to assess the bearing capacity.5. Sumarize and analyze the common strengthen methods and their characteristics of the reinforced concrete ribbed arch bridge. On this basis, through proposing the the principle of macro comparison and selection, the strengthen method can be chosen quickly from qualitatively.6. Strengthening effect analysis and the reassessment of the bearing capacity after strengthening. By comparing the static and dynamic load test results before and after strengthening, the strengthening effect is estimated. And by modeling the strengthened bridge, the actual bearing capacity is evaluated.