控制简支型梁拱组合式钢结构天桥设计的参数研究

Research on Parameters of Controlling the Design of Simply Supported Beam Arch Composite Steel Structured Overpass

依托实际工程,从影响简支型梁拱组合式钢结构天桥安全的各项指标出发,基于安全系数可知控制结构设计的关键指标为自振频率。通过概念分析,对自振频率具有显著影响的参数变量为系梁高、拱高、拉杆宽、拱矢跨比(矢高)、板厚。基于这5个变量,运用Midas Civil对天桥的自振频率进行参数化研究,研究结果表明:自振频率随着拉杆宽度的增加呈现出先增加后降低的规律;基于单位增量的改变程度,对自振频率的影响幅度从大到小依次为梁高、拱高、板厚、矢高。

Relying on the actual project and basing on the indexes that affect the safety of simply supported beam-arch composite steel structure footbridge,the key index which controls design of the structure is natural vibration frequency according to the safety factor.Through conceptual analysis,the parameter variables that have significant influence on the natural vibration frequency are tie beam height,arch height,pull rod width,arch rise-span ratio(rise height)and slab thickness.Based on these five variables,the study of the the natural vibration frequency of the overpass is parameterized by Midas Civil.The research results show that the natural frequency increases first and then decreases with the increase of the width of the pull rod,and based on the change degree of unit increment,the range of influence on natural vibration frequency from large to small is tie beam height,arch height,slab thickness and rise height.