Research On Mechanical Properties Of Large Span Three-Town Cable Supported Bridges

Abstract:

This study focused on mechanical property of large span three-town cable supported bridges, including suspension bridge, cable-stayed bridge and cable-suspension Bridge. The method was through the design of these type bridges to compare their mechanical characteristic. The main span of these bridges was 1400 meter. The result of this investigation clarify that moment diagram of box girder of the three bridges is similar to each other after cable force optimum. As a whole, internal force of beam and town of cable-stayed bridge is largest. Additionally the stability of cable-stayed bridge is not well because the axis force of its box girder is larger. However, the ratio of the natural frequencies of the flexural and torsional vibrations is larger than others. So the aseismic and wind-resistant behaviors of cable-stayed bridge is best. Internal force of beam and town of suspension bridge is smallest and its stability is highest, except the moment of bottom of the middle town due to live load, while the ratio of the natural frequencies of the flexural and torsional vibrations is lowest. So, the aseismic and wind-resistant behaviors of suspension bridge is worst. Internal force of beam and town of cable-suspension Bridge is between the two formers and the advantages are highlighted.