西部高墩大跨径桥梁桥墩的失稳载荷识别方法  

Research of Buckling Load Identification Method about Piers of Western High Pier Long-Span Bridges

作　　者：杜玲[1] 李范春[1] 

机构地区：[1]大连海事大学交通运输装备与海洋工程学院,辽宁大连116026

出　　处：《应用基础与工程科学学报》2016年第2期304-314,共11页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(5100906)

摘　　要：以高桥墩简化模型为基础,从动力学基本方程出发,推导了轴向压力下的自由端附有质量悬臂梁横向固有频率的平方与压力荷载之间关系的精确数值解的表达式.采用变分方法给出了其近似解的表达式,其图像是一条直线,并利用有限元方法求出有限元解.取不同的集中质量,将精确数值解、近似解和有限元解绘制在同一坐标系下进行比较,而且精确数值解和近似解的斜率之间的相对误差不超过10%,得出轴向压力下的自由端附有质量的悬臂梁的固有频率的平方与轴向力呈近似线性关系的结论.精确数值解与近似解所得失稳载荷的相对误差均不超过15%,满足工程要求,而且,随着集中质量的增加,误差有明显减小趋势.以此为基础,只要通过实验测量出任意两种数值不同的荷载工况下的高桥墩结构固有频率,就可以识别出它的弹性失稳荷载.Based on a simplified model of the high pier,from the basic equation of dynamics,the expression of exact numerical solutions( ENS) of the relationship,which was between the square of horizontal natural frequency and pressure load of the cantilever beam with quality attached to the free end subjecting to vertical pressures,was obtained. The expression of approximate solutions( AS) derived from the variational method and it was an image of a straight line. Finite element solutions( FES) were calculated by finite element method. The exact numerical solutions,approximate solutions and finite element solutions were drawn in the same coordinate system to compare with each other with different concentrated mass. And the relative error range between the curve slope of exact numerical solutions and approximate solutions was no more than 10%. The conclusion of approximate linear relationship that is between the square of the natural frequency and axial force of the cantilever beam with quality attached to the free end subjecting to the vertical pressures is got. The relative error of buckling load between exact numerical solutions and approximate solutions did not exceed 15%,which could meet engineering requirements. Moreover,with the concentrated mass increasing,the error had significantly reducing trend. On this basis,as long as the natural frequencies of the high pier at any two different values of load conditions are measured by experimental methods,elastic buckling load can be identified. So the no damage test method to identify the elastic buckling load of the high pier is given.

关 键 词：高桥墩 固有频率 变分 弹性失稳 荷载识别 

分 类 号：U446[建筑科学—桥梁与隧道工程]