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工程科学与技术:2019,51(4):75-83
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拉索索力增量校验系数检定方法研究
(1.北京交通大学 土木建筑工程学院, 北京 100044;2.中国公路工程咨询集团有限公司, 北京 100089;3.中国铁道科学研究院 基础设施检测研究所, 北京 100081)
Investigation on Rating Method of Cable Force Increment Adjustment Factor
(1.School of Civil Eng., Beijing Jiaotong Univ., Beijing 100044, China;2.China Highway of Eng. Consultants Corp., Beijing 100089, China;3.Infrastructure Inspection Research Inst., China Academy of Railway Sciences, Beijing 100081, China)
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投稿时间:2018-04-12    修订日期:2018-11-01
中文摘要: 拉索结构在铁路桥梁中运用越来越广泛,现有铁路桥梁检定规范中无拉索结构的检定要求。现有桥梁规范或理论研究的检定方法大多基于索力或频率校验系数,鲜有文献或规范对拉索的索力增量校验系数进行可行性研究或规定。此外,在计算校验系数时,拉索索长应如何合理选取、索力理论计算采用的有限元计算模型如何确定,仍有待于进一步研究确定。基于此,作者建议了索力增量校验系数的检定方法,并通过案例分析比较确定了拉索索长的合理计算方式和索力理论计算模型。首先基于弦张理论和能量法分别推导了不同边界条件下拉索索力精确计算公式,并考虑振动频率比建立了外载作用下拉索索力理论简化模型,在简化模型基础上推导了索力增量校验系数。试验表明:索力精确求解方法计算结果分别与有限元计算结果和简化求解方法求解结果吻合较好;通过索力、索力差和频率比较发现,实测频率转换为实测索力过程中应选择合理的拉索索长。理论索力可按全桥有限元模型确定,拉索理论振动频率可按与全桥有限元模型索力等效的局部模型确定。与振动频率校验系数、索力偏差率以及索力校验系数相比,索力增量校验系数反映出的各吊杆变化幅度显著,能评定拉索结构技术状况,可作为拉索结构检定标准,适用于评价考虑抗弯刚度的影响参数μ>80的中长吊杆。
Abstract:Cable structures are more and more widely used in railway bridges, however there is no rating requirement for the cable structures in the current code for rating existing railway bridges yet. Most of the rating methods are based on were based on the adjustment factor for the cable force or frequency in the existing bridge standards or theories, while few of them are paid attention to the studies or requirements about the cable force increment adjustment factor were carried out in current literatures or specifications. In addition, further study and validation should be firmly confirmed on how to reasonably select the cable length and how to determine the finite element model for the theoretical calculation of cable force in calculating the adjustment coefficient. Based on the above, the rating method of cable force increment adjustment coefficient was proposed, and the reasonable calculation method of cable length and theoretical calculation model for cable force were determined by the comparison of case study. The cable force calculation formula under different boundary conditions was accurately derived based on the string theory and energy method, and the simplified calculation model of cable force loaded was suggested considering vibration frequency ratio, and the increment adjustment factor of cable force was derived on the basis of the simplified model. Experimental cases demonstrated that the results by the accurate methods of cable force is in good agreement with the result of finite element calculation and the simplified method. By comparing with the cable force, the cable force variation and the basic frequency, the cable length should be reasonably selected for the measured cable force calculation during the transition from the measured frequency to the cable force. The theoretical cable force can be determined according to the finite element model of overall bridge, and the vibration frequency of the cable can be determined according to the local cable model equivalent to the cable force of the finite element model of overall bridge. Compared with the adjustment coefficient of vibration frequency, cable force deviation rate and cable force adjustment factor, the increment adjustment factor of cable force can remarkably reflect the variation amplitude of the cable force and evaluate the technical status of cable structure, which can be used as the rating standard of cable structures and suitable for evaluating the medium length hangers with the bending stiffness affecting parameter μ>80.
文章编号:201800419     中图分类号:TU446.3    文献标志码:
基金项目:中国铁路总公司科技研究开发计划课题(2017G002-J);中咨集团科技项目(zzkj-2017)
作者简介:桂成中(1984-),男,工程师,博士.研究方向:桥梁养护检测研究.E-mail:guicz.cqu.edu@163.com
引用文本:
桂成中,宋国华,柯在田,齐法琳.拉索索力增量校验系数检定方法研究[J].工程科学与技术,2019,51(4):75-83.
GUI Chengzhong,SONG Guohua,KE Zaitian,QI Falin.Investigation on Rating Method of Cable Force Increment Adjustment Factor[J].Advanced Engineering Sciences,2019,51(4):75-83.