大跨度悬索桥桥塔地震纵向损伤特征研究

Study on the seismic longitudinal damage characteristics of the tower of long-span suspension bridge

为对大跨度悬索桥桥塔基于性能的抗震设计提供依据,对大跨度悬索桥桥塔在地震作用下的纵向损伤特征进行初步探究。以某大跨度悬索桥为工程背景,采用大型通用有限元软件ADINA建立地震分析模型,将20条实测地震波沿纵桥向输入,采用IDA方法,对塔中和塔底两个潜在塑性铰区的塑性损伤发展全过程进行逐级观察。结果表明:随着地震等级的增加,塔底和塔中截面的塑性损伤有协同发展趋势,但塔底截面的塑性损伤发展速度远大于塔中,因此最终的桥塔破坏形式为塔底截面破坏而导致的桥塔动力失稳。

In order to provide basis for seismic research of the tower of long-span suspension bridge,the longitudinal damage characteristics of the tower of long-span suspension bridge under earthquake action is explored.A finite element model is established used ADINA by taking a long-span suspension bridge as the example and the development characteristics of plastic damage of the tower is observed by 20 earthquake excitations with increasing intensity in the longitudinal direction.It is found that with the increase of earthquake intensity,the development of the plastic damage at the bottom of the tower and in the middle of the tower bottom is synergistic.However,the rate of development of the plastic damage at the bottom of the tower is far greater than that in the middle of the tower,which leads to the low level plastic damage degree in the middle of the tower when the final section fails at the bottom of the tower.