装配式铝合金人行天桥结构设计及性能分析

Structural Design and Performance Assessment of Prefabricated Aluminum Pedestrian Bridge

铝合金人行天桥因质量轻、强度高、经久耐用等优势而得到广泛应用,传统的天桥结构设计方法存在分析模型过度简化导致结果偏差较大的问题。基于此,本文给出了一种装配式铝合金人行天桥的结构设计方法,用于提高结构设计分析结果的准确性和可靠性。以珠海市某天桥为例,建立该天桥的精细化有限元分析模型,并对其强度、刚度和自振频率进行验算。结果表明:基本组合荷载作用下桁架梁的应力最大,且最大拉应力和最大压应力分别为设计强度的15.5%和14%,人群荷载与恒载作用下桁架梁的应力接近;天桥的最大挠度为最大竖向挠度允许值的28%,天桥的宽跨比是最小允许宽跨比的3.8倍;天桥侧向和竖向固有频率分别为最小允许值的1.92倍和1.87倍,均满足规范要求。

Aluminum alloy pedestrian overpasses have been widely used due to their advantages of light weight,high strength,and durability.However,traditional bridge structure design methods suffer from the problem of excessive simplification of analysis models,leading to significant deviation in results.To this end,this paper introduces a method for the structural design of the prefabricated aluminum pedestrian bridge.Taking a certain pedestrian bridge in Zhuhai as an example,a refined finite element analysis model of the bridge was established,and its strength,stiffness,and natural frequency were verified.The results showed that the stress of the truss beam was the highest,and the maximum tensile stress and maximum compressive stress were 15.5%and 14%of the design strength respectively,under the basic combination load.The stress of the truss beam under crowd load and dead load was similar;The maximum deflection of the overpass was 28%of the maximum allowable vertical deflection,and the width to span ratio of the overpass was 3.8 times the minimum allowable width to span ratio;The lateral and vertical natural frequencies of the pedestrian bridge were 1.92 times and 1.87 times the minimum allowable values,respectively,all of which met the requirements of the specifications.