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高速铁路中小跨度桥梁与轨道相互作用研究

Interaction between Continuously Welded Rail and Medium/Small Bridges of High-speed Railway

【作者】 闫斌

【导师】 戴公连;

【作者基本信息】 中南大学 , 土木工程, 2013, 博士

【摘要】 在中国高速铁路建设中,为节约耕地、减少路基沉降等问题,往往以桥梁代替路基作为轨道的支撑结构,由此产生的无缝线路和铁路桥梁之间的相互作用问题,是高速铁路桥梁设计的重要课题之一。桥上铺设无缝线路后,在温度、徐变、制动力和地震作用下,梁轨间产生相对位移,由于梁轨之间的非线性约束作用,将在轨道、梁体和墩台中引起纵向力。该纵向力既是轨道强度和稳定性的控制性指标,也是影响桥梁下部结构设计的重要因素。高速铁路桥梁中,应用范围最广、数量最多的结构形式为标准跨度的简支梁和连续梁桥。在跨越既有线时,也常采用斜拉桥的形式。研究中小跨度简支梁、连续梁和斜拉桥上梁轨系统的受力特性有其必要性。本文在吸收和借鉴国内外研究成果的基础上,建立了可进行温度、活载和地震响应分析的梁轨系统力学模型,编制了相关实用程序,对高速铁路中广泛使用的标准跨度简支梁、连续梁,以及应用日益广泛的斜拉桥进行了梁轨相互作用分析,探讨了设计参数对梁轨系统受力的影响,对简支梁、连续梁和独塔斜拉桥上梁轨系统的受力特点进行总结,并提出设计建议,本文主要内容包括:1、推导了线路纵向阻力的迭代公式,采用非线性杆模拟线路阻力、带刚臂的梁单元模拟梁体,建立了考虑加载历史和邻跨结构的梁轨系统模型。在进行温度和活载作用分析时,考虑了滑动支座摩阻力、扣件竖向刚度的影响;在进行地震响应分析时,还考虑了桩-土共同作用、桥墩非线性、地震动行波效应,以及梁体间的碰撞效应。通过与相关文献中的算例进行对比,证明模型的正确性。2、采用Visual Basic.net图形界面和Access数据库技术,基于ANSYS二次开发,开发了标准跨度简支梁和连续梁的实用有限元程序SBCWR和CBCWR,可分析温度、活载和地震,以及三者耦合作用下的梁轨系统响应,并探索性地开发了基于客户端/服务器端的梁轨分析程序。3、探讨了简支梁标准跨度的双线无砟轨道简支箱梁的跨数、截面形式、线路阻力、路基段钢轨长度、滑动支座摩阻系数、下部结构刚度等因素对梁轨相互作用的影响,分析不同地震激励方向和行波效应下的梁轨系统动力响应,以及轨道结构对简支梁桥动力特性和碰撞效应的影响。4、针对主跨为40-100m的双线无砟轨道连续梁,探讨相邻简支梁跨数、桥墩刚度等因素的影响。针对大跨度连续梁,设置多种小阻力扣件和钢轨伸缩调节器组合布置方案进行比选。参照国内外规范检算标准,推导无缝线路固定区极限温度跨长及各跨连续梁桥制动墩纵向刚度限值,讨论碰撞效应对连续梁上无缝线路的影响。5、分析了某槽型截面独塔斜拉桥梁轨系统纵向力分布规律,探讨相邻简支梁支座布置、斜拉桥结构体系、截面形式、桥塔和拉索温度变化及风载的影响;分析一致激励和行波效应下,斜拉桥梁轨系统的动力响应。

【Abstract】 In China’s high-speed railway, the embankment was often replaced by the bridge as the support of track to save farmland and reduce embankment settlement. The interaction between the continuously welded rail (CWR) and bridge was one of the important topics in high-speed railway bridge.After the CWR was laid on the bridge, the relative displacement took place between beam and track under the action of the temperature, creep, braking force and earthquake. Due to the nonlinear constraint between beam and track, the longitudinal force was generated in the track, beam and pier. The longitudinal force was both a controlling indicator of the track strength and stability. It was an important factor to affect the bridge design as well. In the high-speed railway, the bridge forms of the widest applied range and largest quantity were simply-supported beam and continuous beam with standard span length. The cable-stayed bridge was also often used across the existing line. It was necessary to study the force characteristics of the beam-track system on medium and small simply-supported beam, continuous beam and cable-stayed bridge.In this dissertation, on the basis of existing researches, the beam-track mechanics model for the temperature, live load and seismic response analysis was established. The related utility program was compiled. The beam-track interaction was analyzed for standard span length simply-supported beam and continuous beam widely used in high-speed railway as well as cable-stayed bridge of the increasingly widespread application. The impact of the design parameters on the beam-track system was explored. The beam-track system force characteristics on simply-supported beam, continuous beam and single-tower cable-stayed bridge were summarized, and the design proposals were put forward. The main contents in this dissertation included:1. The iterative formula of track longitudinal resistance was derived. The nonlinear bar elements were used to simulate the track resistance and the beam element with rigid arms was used to simulate the bridge. The beam-track finite element model was established considering the loading history and adjacent structures. Analyzing the temperature and live load, the impact of the movable bearing friction and vertical stiffness of the fastener was considered. Analyzing the seismic response, the pile-soil interaction, pier nonlinearity, traveling wave effect and pounding effect between beams were also taken into account. Compared with the examples in the relevant literatures, the correctness of the model was proved.2. Based on the ANSYS, the practical finite element programs, SBCWR and CBCWR, for simply-supported beam and continuous beam with the standard span length were developed by the Visual Basic.net graphical interface and Access database, which could be used to analyze beam-track system response under the temperature, live load, earthquake and three coupling. Based on the client/server, the beam-track analysis program was developed.3. It was explored that the span number of double unballasted track simply-supported box beams with standard span length, cross-sectional form, track resistance, roadbed track length, movable bearing friction, substructure stiffness and other factors made the impact on the beam-track interaction. Under the different seismic excitation directions and traveling wave effects, the dynamic response to the beam-track system was analyzed, and it was also analyzed that the track made the impact on the dynamic characteristics and pounding effect of simply-supported beams.4. It was explored that the span number of adjacent simply-supported beams, pier stiffness and other factors made the impact on the continuous beams with a main span of40-100m carrying double unballasted track. For the large continuous beam, the small resistance fastener and track expansion device arrangements were set to do the comparison. Based on the related standards, the maximum expansion length and minimum stiffness of continuous beam pier were put forward. It was discussed that the pounding effect made the impact on the CWR and continuous beam.5. The longitudinal force distribution for the beam-track system of an U-shape section and single-tower cable-stayed bridge was analyzed, and the impact of adjacent simply-supported beams, cable-stayed bridge structure system, cross-sectional form, tower and cable temperature variation as well as wind load was explored. Under the action of uniform excitation and traveling wave effect, the dynamic response to the beam-track system of cable-stayed bridge was analyzed.

  • 【网络出版投稿人】 中南大学
  • 【网络出版年期】2014年 03期
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