适用于新活载标准的铁路桥梁动力系数研究

【作者】 戴慧敏；

【导师】 郭向荣；

【作者基本信息】 中南大学 ， 土木工程， 2011， 硕士

【摘要】 我国高速铁路的荷载模式采用ZK活载图示,其对应的动力系数为引用UIC荷载图示的公式,而随着我国高速铁路运营里程的大量增加,有必要对线性桥规中ZK活载对应的动力系数进行进一步计算研究。本文以现有已建和在建的部分常用跨度简支梁和连续梁或连续刚构桥为研究对象,对现行桥规中的动力系数的合理性进行了分析,为进一步制定适用于ZK活载的动力系数提供参考。本文的主要内容如下：(1)综述了国内外桥梁动力系数的研究历史和研究现状,简要介绍了部分国家规范桥梁动力动力系数的计算方法,阐述了对适用于我国ZK活载的动力系数研究的必要性。(2)用梁段单元和空间梁元对若干座典型桥梁建立了动力学空间有限元分析模型,并对各桥的自振特性进行了分析计算,同时建立了车桥系统动力学分析模型以便于进一步进行桥梁运营动力系数仿真计算与分析。(3)对各典型桥梁在高速列车通过时的车桥系统空间动力响应进行了仿真计算与分析,得出了各工况下桥梁的运营动力系数,并将其变化趋势的峰值速度与理论共振速度进行了对比分析,二者吻合良好。(4)通过对列车荷载和ZK活载的等效线性荷载分别乘以运营动力系数和设计动力系数后二者的对比分析,对现行桥规中动力系数的合理性进行了研究。结果表明：现行桥规中动力系数计算公式在桥梁设计时偏于保守,且连续梁比简支梁和连续刚构桥更加保守,故有必要进一步完善现行规范中动力系数计算公式。更多还原

【Abstract】 The train live load mode of our high-speed railway is ZK live load. Their corresponding dynamic coefficients are quoted from the UIC load. With high-speed railway operational mileage large increasing in our country, it is necessary to further analysis dynamic coefficient formula of ZK live load. This paper takes part of some existing and under construction simple supported beam bridges, continuous girder bridges and continuous rigid-frame bridges as the research objects, analyses the rationality of dynamic coefficients of existing bridge codes, so as to provide reference for establishing the dynamic coefficients for ZK live load. The major work are as follows:(1) The research history and status of bridge dynamic coefficients at home and abroad in recent years are summarized, the bridge dynamic coefficient calculation methods of some countries’standards are briefly introduced, and the necessity of the study of dynamic coefficients of ZK live load applicable in our country is expounded.(2) Beam segment element and space beam element are used to establish numbers of typical bridges’dynamic space finite element analysis model, and the vibration characteristics of these bridges are analyzed and calculated; also the train-bridge system dynamics analysis mode is established for simulation calculation and analysis of bridge operation dynamic coefficients.(3) Through the simulated calculation and analysis of various typical bridges’train-bridge system space dynamic response when the high-speed train passes by, bridge operation dynamic coefficients under various operating conditions are obtained; peak speed along variation trend and theoretical resonance speed are analyzed and compared, which is shown that the two results coincide with each other well.(4) According to the contrast analysis of the equivalent linear load of train loads and ZK live load which have multiplied by operation dynamic coefficients and design dynamic coefficients separately, the rationality of dynamic coefficients of existing bridge codes are studied. The results show that the current calculation formula for dynamic coefficients of bridge rules tends to be conservative in bridge design, and the continuous girder bridge tends to be more conservative than simply supported beam bridge and continuous rigid-frame bridge, so it is necessary to further perfect the dynamic coefficient calculation formula for current specification.更多还原