以昆明市某(12.2+49.1+12.2)m人行桥为工程背景,介绍该单跨无吊杆人行悬索桥的结构体系,相关设计参数和动、静力计算分析,并探讨恒载、活载和温度荷载作用下主缆、加劲梁和桥塔的受力特点;分析了主梁两端不同的边界条件对结构振动使用性能的影响和抗震性能,并对人群同步荷栽作用下桥梁的响应时程进行计算。计算结果表明:将主梁两端固结能有效提高结构自振频率,从而满足人行桥振动使用性能要求。
Taking a (12.2 plus 49. 1 plus 12.2) m pedestrian bridge in Kunming as the engineering background, the structure system, the related parameters and the static and dynamic analysis were introduzed. Meanwhile, the mechanical characteristics of main cable, stiffening girder and bridge tower were evaluated under the condition of constant load,live load as well as temperature load. Then the bridge' s natural vibration characteris tics and the earthquake resistant behavior were compared under different boundary conditions of the stiffening girder, and the vertical acceleration was calculated by time history analysis under pedestrian load. The results show that fixing the two ends of the stiffening girder can improve the natural frequency efficiently so as to meet the requirements of pedestrian bridge.