钢结构人行天桥自振频率优化分析

为了提高人行天桥的整体安全性,该文在结构设计的理论基础上提出了一系列有效措施。以楚雄市某钢箱人行天桥为依托,采用结构优化的方式,利用有限元软件建立参数化模型,以梁高和二期荷载为变量,以基频和时程为目标函数,分别将钢箱梁梁高增加20 cm和30 cm,将原混凝土铺装更换为轻型材料聚氨酯塑胶,天桥的基频提高到原来的两倍多。结果表明:梁高和铺装对人行天桥抗震性能有着显著的影响,增加梁高,采用轻型铺装,能有效地优化人行天桥的自振频率,保证了结构安全,可为类似结构的安全运行提供有力参考。

Optimization Analysis of Natural Vibration Frequency of Steel Structure Pedestrian Bridge

In order to improve the overall safety of the pedestrian bridge,this paper puts forward a series of effective measures based on the theory of structural design.Based on a steel box pedestrian bridge in Chuxiong City,the parameter optimization model was established by using the finite element software.The beam height and the second stage load were used as variables,and the fundamental frequency and time history were used as the objective functions.The beam height was increased by 20 cm and 30 cm,and the original concrete pavement was replaced with a lightweight material polyurethane plastic.The base frequency of the bridge was more than doubled.The results show that the beam height and pavement have a significant impact on the seismic performance of the pedestrian bridge.To increase the height of the beam and applying the light pavement can effectively optimize the natural vibration frequency of the pedestrian bridge,ensure engineering safety and provide references for safe operation of similar projects.