Wind-resistant Performance Analysis And Experimental Investigation On Long-span Cable-stayed Bridges

Cable-stayed bridge has been rapidly developed due to its large spanning capacity, beautiful shape and economical advantage. In recent years, the cable-stayed bridge span has continuously increasing, the stiffness and damping ratio of these structures decrease consequently, and wind resistance stability has become more and more important. This thesis analyzes the wind-resistant behaviors of an asymmetric single-pylon cable-stayed bridge with steel box girder.In this paper, those key points had been studied on:natural vibration property, Aerodynamic parameter identification, aerostatic wind response and flutter stability. The main contents of the work can be summarized as follows:(1) A three dimensional space finite element analysis model was constructed to analysis the static force coefficients of the bridge. Natural vibration properties were analyzed to do the section model wind tunnel test and research on wind-induced vibration later.(2) Through the section model dynamic wind tunnel test, flutter critical wind speed was obtained and flutter stability was evaluated. The flutter critical wind speed under three different initial wind attack angle meet the requirements of the specification.(3) Based on the CFD numerical methods, the three component coefficients of the girders were calculated. The forced vibration method was used to identify the flutter derivatives of the girder. Aerostatic wind response was computed under different wind attack angle.(4) Two degree of freedom coupling flutter analysis was applied on the cable-stayed bridge. The flutter critical wind speed was calculated by compiling matlab language program. Using the flutter derivatives to ascertained the critical state of the flutter.