The Old Bridge Carrying Capacity Evaluation And Safety Evaluation Method Research

With the rapid development of the cause of highway bridges, the carrying capacity of the existing bridge reducing, the old bridges widening and other factors make carrying capacity evaluation and researching safety assessment methods for the old bridges imminent. The discuss about the methods of research and evaluation for carrying capacity of the bridge structure of concrete Disease Mechanism has a great significance. In this paper taking a highway overpass as the basis, it selects the typical bridge’s structure following the researchs:First, it elaborates the current situation of the development of existing bridge at home and abroad, the old bridges’ assessment methods and development, then it researchs the main disease mechanism of concrete, the causes and methods of carrying capacity on this basis, and it provides a solid theoretical foundation for thefurther assessing the carrying capacity and the safety assessment of old bridges. It selects the typical structures of the continuous prestressed box girder and the prestressed hollow plate bridge to study and investigate their historical conservation, and make special inspection, according to the 《Evaluation of highway bridge carrying capacity testing procedures》(JTG / T J21-2011), two reinforced bridges obtain good results. Using the Midas Civil 2015 and Dr.Bridge to finite element model and Combined with the China’s former standard《Code For Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts》(JTJ 023-85) and the Chinese new standard 《Code For Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts》(JTG D62-2004), it calculations about the the original design and the design of the carrying capacity after reducted, and obtains that the reinforced bridges meet the regulatory’s requirements, but the surplus amount of carrying capacity is lower.Through this study, it has a certain reference value for the old bridges’ carrying capacity assessment and the study of safety assessment methods in the future.