Buffeting Time-Domain Analysis And Study On Wind-Resistance Measure Under Construction For Super Kilometer-Span Highway-Railway Steel Truss Cable-Stayed Bridge

Since the application of computer technology and the invention of new materials have greatly promoted the development of modern bridge, cable-stayed bridge, which is of the advantage of appealing design and reasonable price, is quite popular. Among those constructed or under-construction cable-stayed bridges, they almost present the features of high tower, long span, flexibility and weak damp. In terms of structural wind resistance, cable-stayed bridge belongs to wind sensitive structure. In the wind-resistant design of bridges, buffeting can occur in any wind speed, which will produce great influence on construction safety and driving comfort, therefore buffeting has always been taken seriously by designers.In this thesis,a highway-railway cable-stayed bridge was taken as example, making buffeting linear time domain analysis respectively on its after-construction state and construction state and investigating buffeting suppression effect of setting up wind resistance cable at the construction state. The content framework includes:Brief introduction of cable-stayed bridge development and theoretical knowledge of wind engineering;According to the structure features of large span cable-stayed bridge and the characteristics of natural wind at bridge site, the three-dimensional fluctuating wind field of the cable-stayed bridge is simplified as independent one-dimensional random variable to carry out wind field simulation.Utilizing Ansys13.0 to establish the finite element model, making dynamic characteristics analysis on after-construction state and construction state, obtaining the aerostatic force coefficient through wind tunnel experiment and getting first-order derivative of each aerostatic force coefficient through matching the aerostatic force coefficient;Calculating resistance coefficient of each bridge tower through CFD software, making time domain treatment on buffeting force and self-excited force, and then uploading them with static wind force to a cable-stayed bridge to carry out liner buffeting time domain analysis;Investigating the buffeting suppression effect of setting up wind resistance cable at the most unfavorable construction state.