自锚式斜拉-悬吊协作体系桥梁动力性能

讨论了自锚式斜拉-悬吊协作体系在主梁、辅助墩及主塔基础等不同约束方式下结构动力特性。通过分析得出该体系桥梁自振周期长,振型密集且振型间相互耦合;缆、塔、梁共同参与振动,提高了结构的扭转频率,结构的抗风稳定性较好;加劲梁受到主缆水平分力和斜拉索水平分力的共同作用,降低了结构的弯曲刚度,需加大截面尺寸;桥梁各阶振型频率随主梁弹性约束刚度的增加而增加,一阶纵飘频率受弹性约束刚度影响比较显著,其他振型频率影响较小;通过设置边跨辅助墩,可以提高协作体系的结构刚度,增加各阶振型的频率;主塔对结构动力特性的影响取决于基础对塔底的约束强度,当群桩基础足够强大时,其自振频率仅略小于沉井、沉箱基础。

Dynamic characteristics for self-anchored cable-stayed suspension bridges

The dynamic property of self-anchoring cable-stayed&suspension cooperation bridge is studied concerning different restraints including the girder,the assisting pier and the main tower.It is stated that this bridge possesses a rather high free vibration period with closely-related vibration modes.The participation of cables,tower and girders in the vibration has increased the torsion frequency which brings about a better resistance against the wind.The size of stiffening beams which are adversely affected by...