Analysis Of The Chain Bars Between Girders On Structural Behaviors For Cable-Stayed Bridges

Our basic construction for transportation was developed rapidly, and so does the urban bridge construction. More bridge engineers focus on structures’artistic performance and their capacity for pedestrians. Cable-stayed bridge as a long span structure and a landmark enjoyed a widely use, and more concentration lied on its serviceability and safety, which made load testing to be an essential evaluation method. By arranging the double-deck bridge with foot bridge and highway bridge, traffic capacity can be satisfied and humanistic concern can also be reflected. The chain bars used in double-deck cable-stayed bridges as a supplementary structure have some special function to improve structures’ behavior.Based on Mianyang Bridge’s loading test, the development history of cable-stayed bridges and special-shaped cable-stayed bridges were illustrated and background was introduced for foot bridges and double-deck bridges. In this paper, the theory of infinite element was briefly given, and then stride frequency of pedestrians were studied according to present research in China and abroad. Also the evaluation methods of vibration comfort for foot bridges and three typical ways to solve Eigen vector were carried out, which provided theoretical basis for this thesis. In this thesis, the main objects about the effects of chain bars on bridges’ structural behaviors are followed:1、Based on infinite element program, simulation computation was carried out for Mianyang Bridge, and the strained condition were calculated under completed status of the bridge.2、Two loading tests with chain bars and without chain bars were performed to test bridges’ serviceability and safety. And also the infinite element model for the bridge with chain bars and without chain bars were tested. The outcomes of these two conditions were compared.3、By adjusting clain bars’stiffness, numbers and positions etc., the influence of links on Mianyang Bridge’ serviceability and safety were analyzed. Based on "avoiding sensitive frequency method", to test the effects of whether the clain bars are existed or not on the pedestrians’comfort, and finally the reasonable arrangements of links were proposed.