悬索桥超高桥塔的刚度和风致响应

为了探讨悬索桥超高桥塔的刚度和风致响应问题,围绕顺桥向A字形布置混凝土桥塔(不同底部张开量)和顺桥向独柱形布置混凝土桥塔(不同塔柱截面)展开研究。利用有限元分析软件建立了2种类型桥塔的裸塔自立状态有限元模型,计算对比了桥塔刚度以及静风响应,同时采用时域分析方法计算桥塔的抖振响应,对比分析了在桥塔横向构造形式一定的前提下,不同类型方案对超高桥塔刚度和风致响应的影响。分析结果表明,顺桥向A字形桥塔的整体刚度较独柱形桥塔大;在顺桥向静风作用下,独柱形桥塔塔顶位移比A字形桥塔大得多;在顺桥向脉动风作用下,独柱形桥塔塔顶抖振位移响应的脉动程度远大于A字形桥塔。

Stiffness and Wind-Induced Responses of Very High Towers of Suspension Bridge

To study the stiffness and wind-induced responses of the very high towers of suspension bridge,the A-shape concrete tower(with different opening distances between footings of the tower columns) and the isolated column concrete tower(with different sections of the tower columns) arranged in the longitudinal direction of the bridge were investigated.The analysis software was used to establish the finite element model for the two types of the towers in the state of free standing and the stiffness and static wind responses of the towers were calculated and compared.Meanwhile,the time-domain analysis method was used as well to calculate the buffeting responses of the towers and on condition that the transverse structural forms of the towers were given,the effect of the different types of the towers on the stiffness and wind-induced responses of the very high towers was compared and analyzed.The results of the analysis demonstrate that the global stiffness of the A-shape concrete tower arranged in the longitudinal direction of the bridge is greater than that of the isolated column concrete tower and under the respective action of the static wind and fluctuating wind in the longitudinal direction of the bridge,the displacement at the top of the isolated column concrete tower is far greater than that at the top of the A-shape concrete tower and the fluctuating degree of the buffeting displacement response at the top of the former is also far greater than that at the top of the latter.