斜拉人行天桥的动力性能研究

Dynamic Behavior of a Cable-stayed Flyover

斜拉人行天桥由桥、索和塔共同构成,不仅跨度大、体型复杂,而且它们之间的相互作用呈现出明显的空间振动特性,本文根据D’Alembert原理推导预应力悬挂结构的振动微分方程,得出预应力悬挂结构的自振频率与索的截面面积、弹性模量及长度有关,与结构的质量有关,与索支承结构的刚度有关,而与索中预应力的大小没有关系.通过对斜拉人行天桥的构成分析,采用弹簧串联和并联的概念,提出通过改变索的截面积来调整结构自振频率的方法,并以某小区斜拉人行天桥为例进行说明.

The span of a cable-stayed bridge is big,the structure is complex,and all members of the structure affect each other.The differential equation of vibration on pre-stressed suspended structures is derived through the theory of D＇Alember and factors to affecting the frequency of pre-stressed structure are analyzed.These factors include the section area,elastic modular,length of cable,and mass of whole structure,whereas pre-stress is not inclucled.A way to adjusting the frequency of the cable-stayed flyover is developed through modification on section area of the cable on the basis of the concept of spring in series or in parallel by analyzing members of the cable-stayed flyover.The method using the design of one cable-stayed flyover is used in one community.