Analysis And Assessment Of The Capacity Of The Existing Double-Curved Arch Bridge

Double-Curved arch bridge is a new style bridge in our country which born in the middle 1960s in Wuxi city Jiangsu Province. During 1960s to 1980s, this style is widely used in road and bridge because of its many advantages, such as simple in construction, less consumed in steel and lower requirement to the lifting equipments. But with the rapid growth of Chinese economic and the high speed development in transport, especially the increase of the traffic road scales, and heavy load vehicles also largely increase along with it. Now most of double-curved bridge has been not meet the normal requirements and a variety of damage have been appeared, then carrying capacity also decreased rapidly, those caused a lot of serious hidden traffic dangers. It is obvious that we urgently needed to evaluate the carrying capacity for these double-curved bridges so that we can give some direct advice to their conservation,revise and rebuild. The main research about this paper is as follows:1,The object study is an existing double-curvature arch bridge in Shaoyang Hunan Province. We use MIDAS software, and use spatial beam finite element model grid method to establish the model. We combine the real measured Arch axis, in order to easily reflect the force characteristic of this bridge itself and be able to build the more simple model as far as possible. Then we compare the theory base frequency with the dynamic test. Hence, we can obtain the best imitate result.2,We introduce a structural damage theory which based on the frequency changes, so that we can achieve the aim of revising the finite element model. Then carry on the finite element analysis by using this tested bridge, and evaluate the carrying capacity through checking out the bridge's appearance. It is true that the revision model frequency is close to the experiment obtains frequency.3,We compared the experiment value with the theory value about displacement,strain and so on. From the analysis result we know that about the qualitative the actual value and the theory value are consistent, and individual data is different from others. So the method in this paper and the tested result about bridge result can use to evaluate the bridge bearing capacity.