基于振动频率法的斜拉桥索力测试影响因素  

Influential factors in cable force measurement of cable-stayed bridges based on vibration frequency method

作　　者：吉伯海[1] 程苗[1] 傅中秋[1] 陈雄飞[2] 孙媛媛[1] 

机构地区：[1]河海大学土木与交通学院,江苏南京210098 [2]江苏扬子大桥股份有限公司,江苏南京210004

出　　处：《中南大学学报（自然科学版）》2015年第7期2620-2625,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51278166);高等学校博士学科点专项科研基金资助项目(20120094110009)~~

摘　　要：基于振动频率法,研究拉索自身参数和外界条件对拉索基频的影响。运用拉索静力平衡振动方程,推导考虑阻尼的拉索振动基频计算方法,研究拉索垂度和抗弯刚度对基频计算的影响范围。通过数值计算,分析阻尼器、梁体振动和温度变化等外界条件对基频计算的影响规律,提出斜拉桥索力测试和基频计算建议。研究结果表明:当反映垂度影响的量λ2≤0.9,不可忽略垂度的影响;当反映抗弯刚度影响的量0≤ξ≤210,不可忽略抗弯刚度的影响。拉索安装阻尼器将导致索基频增加,阻尼器安装越远离锚固端对基频的影响越大;拉索越长和直径越小,阻尼器对基频影响也越大。斜拉桥梁体振动时进行索力测试,拉索的基频存在动态波动;拉索温度越高,基频越小。建议选取车流较少、温度稳定的环境进行索力测试以获得较准确的基频。Based on the method of vibration frequency, the influence of cable parameters and external factors on cable fundamental frequency was studied. Calculation method of fundamental frequency was deduced with the static vibration equation equilibrium. And the influential range of cable sag and bending stiffness toward the calculation of the fundamental frequency was studied. Through numerical calculation, the influence of external factors was also analyzed, including damper, beam vibration and temperature variation. Suggestions for cable tension test and calculating fundamental frequency were proposed. The results show that the influence of cable sag can not be ignored when the quantity reacting cable sag λ2≤0.9 and that the influence of cable bending stiffness should be considered when the quantity reacting cable bending stiffness 0≤ξ≤210. The damper on the cable can increase the fundamental frequency. It has greater influence on fundamental frequency when the damper is set fiLrther to the anchoring section. And the longer and smaller dimension of the cable is, the more obvious influence damper has on the fundamental frequency. The vibration of beam causes the dynamic fluctuation of fundamental frequency when the testing work is done. Higher temperature causes testing results of larger fundamental frequency. So, a more accurate value of fundamental frequency can be got when the testing work was done under a small traffic flow and stable temperature environment.

关 键 词：斜拉桥 振动频率法 索力测试 基频 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]