频率法测连续梁拱桥吊杆索力影响因素研究  

Study of Influencing Factors When Using Frequency Method to Test Suspender Forces of Continuous Girder Arch Bridge

作　　者：吴焕庆[1] 欧阳永金 刘世忠[1] 

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]厦门市市政建设开发总公司,福建厦门361012

出　　处：《世界桥梁》2013年第4期54-57,共4页World Bridges

基　　金：国家自然科学基金项目(50968008)

摘　　要：为了准确地测出连续梁拱桥吊杆的基频,进而推算出吊杆索力,基于弦振动理论,建立考虑轴向力影响的弯曲振动偏微分方程,对风荷载及吊杆有效计算长度2个重要参数进行了研究,通过实桥在有风与无风条件下的实测数据与理论计算值进行对比分析。结果表明:采用频率法测吊杆基频时,吊杆上不能有横向外荷载作用;提出按分段修正的方法计算吊杆的有效长度,进而根据修正后的有效计算长度计算吊杆的理论基频,按此方法计算所得的吊杆理论基频与无风条件下的实测基频值误差较小。To exactly test the fundamental frequencies of the suspenders of continuous girder arch bridges and thereby to calculate the forces of the suspenders, the partial differential equation of the flexural vibration taking into account the impact of axial forces was established based on the theory of string vibration, on the basis of which the two important parameters of wind loads and the calculated effective lengths of the suspenders were studied. And the measured data of the real bridge under wind condition and the wind-free condition and the theoretically calculated values were compared and analyzed. The results indicate that when the frequency method is used to test the fundamental frequencies of the suspenders, no external loads in the transverse direction should be found on the suspenders. It is proposed that the effective lengths of the suspenders be calculated via segment-based modification and the calculated effective lengths gained in turn be used to calcu- late the theoretical fundamental frequencies of the suspenders. The gap between the theoretical .2 frequencies of the suspenders gained by using the wind-free conditions is narrow. method and the measured frequencies under the wind-free conditions is narrow.

关 键 词：连续梁拱桥 吊杆 频率法 风荷栽 基频 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]