节点文献
桥上无缝道岔区纵连式无砟轨道受力特性与结构优化研究
Research on Force Characteristics and Structural Optimization for Longitudinal Coupled Ballastless Track Turnout on Large Bridges
【作者】 任娟娟;
【导师】 刘学毅;
【作者基本信息】 西南交通大学 , 道路与铁道工程, 2009, 博士
【摘要】 随着京津城际客运专线的成功铺设和开通运营,我国将有更多的高速客运专线采用预制板纵连式无砟轨道方案。由于高速铁路对线路平纵面要求很高,因此桥隧所占线路延长的比例很大,不可避免地要在桥上无缝道岔区采用纵连板式无砟轨道。本文在充分吸收总结国内外相关研究的基础上,通过理论分析和试验研究,建立了桥上岔区纵连无砟轨道的计算模型与方法,对桥上岔区内的无缝道岔、无砟轨道、桥梁及相关传力结构的受力与变形规律进行较为系统和全面的计算分析,对无砟轨道的主体结构与传力结构进行了较为系统的力学计算、结构设计与优化。主要研究工作与成果如下:(1)分析了桥上岔区无砟轨道的岔梁相互作用关系。对比分析了三种典型桥上岔区无砟轨道结构(雷达型桥上岔区无砟轨道、城市轨道交通中桥上岔区无砟轨道和博格长桥岔区无砟轨道),认为博格纵连式桥上岔区无砟轨道具有明显优势。重点研究了桥上岔区博格纵连式无砟轨道的结构特点、各组成部分功能,以及无缝道岔、纵连式无砟轨道与桥梁的相互作用关系、岔桥传力方式等。(2)建立了桥上岔区纵连无砟轨道的计算模型与方法。基于无缝道岔—纵连板式无砟轨道—桥梁间的纵向相互作用关系和受力特点,针对武广客专雷大桥建立了桥上岔区纵连无砟轨道的“岔(无缝道岔)—板(组合道床板)—梁(桥梁)—墩(桥墩)”一体化计算模型,利用非线性有限元法对模型求解,编制相应计算软件。通过遂渝线新北碚嘉陵江大桥纵连板式轨道的现场测试与理论计算结果的对比,初步验证了计算理论的正确性;对采用类似计算理论和纵连结构的桥上岔区纵连无砟轨道,认为本文所建计算模型与方法是合理可行的。(3)分析了温度影响下桥上岔区纵连无砟轨道的受力与变形规律。在武广客专雷大桥客专无砟350km/h18号可动心轨道岔岔区无砟轨道设计中,针对道床板纵向伸缩刚度、滑动层摩擦系数、固结机构、温度变化幅度等,计算分析了无缝道岔、无砟轨道、桥梁各部分在温度影响下的受力与位移,主要包括基本轨伸缩附加力及伸缩位移、道岔传力部件的受力及尖轨心轨位移、道床板附加力及位移、桥梁墩台水平力、固结机构和端刺等传力结构的纵向力等,得到了温度影响下桥上岔区纵连无砟轨道的受力与变形规律。(4)分析了制动力和偶然荷载作用下桥上岔区纵连无砟轨道的受力与变形特点。针对武广客专雷大桥上岔区无砟轨道,计算分析了制动力和断轨或断板等偶然荷载的作用位置、道床板纵向伸缩刚度、滑动层摩擦系数和固结机构等对道岔、无砟轨道、桥梁及传力结构受力与变形的影响特点,并研究了各相关结构的安全性。(5)评价了武广线雷大桥岔区纵连无砟轨道的总体设计情况,进行了相关部件的力学计算、结构设计与优化。根据桥上岔区无砟轨道的结构特点,研究确定了武广客专雷大桥合理的岔桥相互位置、桥梁支座布置形式及摩擦板的长度值,提出了桥上岔区纵连无砟轨道结构设计的建议,可供实际工程设计中参考应用。对桥上岔区纵连无砟轨道中轨道板、底座板、滑动层等主体结构及硬泡沫塑料板、端刺等传力结构进行了较为详细的受力计算和检算;对滑动层的摩擦系数、耐久性及硬泡沫塑料板的耐久性,借助本人在德国学习期间所得到的相应测试资料进行了研究;对梁缝处结构、固结机构的设置方式及滑动层使用材质等方面提出相关优化措施。
【Abstract】 With the successful construction and operation of Beijing-Tianjin intercity railway line, Longitudinal Continuously Prefabricated Ballastless Track (LCPBT) system will be more and more applied on high-speed railway and Passenger Dedicated Lines (PDLs). Due to the high requirements of railway line plane and profile, bridges and tunnels will have a great proportion on PDLs which results in the inevitable application of LCPBT system in the seamless turnout area on bridges. Based on the comprehensive research of relative fields at home and abroad, a calculation model and method for LCPBT in turnout area on bridge was built by means of the theoretical analysis and experimental study in this thesis. The systematical analysis on forces and distortion of seamless turnout, ballast-less track, bridges and other force-transferring structures were carried out.The research work and main conclusion are divided as follows:(1) Analysis of interaction between seamless turnout and bridges for LCPBT in turnout area on bridge.The LCPBT used in turnout area on bridges showed a significant advantage from the structural contrast with the two other representative ballastless turnout systems on bridges which are respectively Rheda ballastless turnout system and the urban railway track system. Then its structural characteristics, mechanical function of every part were mainly studied. Furthermore, the interaction among seamless turnout, ballasteless track, bridge beam and their force transferring mode werel researched in detail in the thesis.(2) Establishing the computing model and method of LCPBT in turnout area on bridge.Based on the longitudinal interaction relation and force characteristics of seamless turnout-ballastless track-bridge, an integral finite element model of turnout (crossover)-track slab-bridge-pier for LeiDa Bridge turnout on Wuhan-Guangzhou PDL was established. A computing program was developed using the non-linear finite element method, which can solve the complex structure. A compare between site tests and theoretical calculating results was made for the new Beibei-Jialingjiang Bridge on Suining-Chongqing test line, which primarily shows correctness of calculating theory in this thesis. Therefore, the calculating model and method for LCPBT in turnout area on bridges was considered to be reasonable that uses the similar theory with LCPBT on Beibei-Jialingjiang Bridge.(3) Analysis the longitudinal force and deformation rule of LCPBT in turnout area on bridge under temperature’s influence. Taking a ballastless,350km/h, No.18 seamless turnout with movable frog on LeiDa bridge on Wuhan-Guangzhou PDL for research target, forces and distortions of turnouts, slab track, and bridges were calculated with change of some important parameters, such as extensional stiffness of track slab, friction coefficient of the slip membrane, the fixing of anchor point and rail temperature differences. The calculation items include additional forces and displacement for stock rail and slab, forces of turnout force-transfering parts, displacement of switch tongue and noise rail as well as forces of piers, anchor point, fixation point. Consequently, the longitudinal stress and deformation regularities of LCPBT in turnout area on bridges were concluded under temperature’s influence.(4) Analysis the longitudinal force and deformation rule of LCPBT in turnout area on bridge under braking force and occasional force.The ballastless,350km/h, No.18 seamless turnout on LeiDa bridge on Wuhan-Guangzhou PDL was still taken for research target in order to analyse the force-transmission mechamism among turnouts, ballastless track and bridges under braking force or rail/slab breaking force. The influencing factors were analysed, such as position of train braking or rail/slab breaking, extensional stiffness of track slab, friction coefficient of the slip membrane, the fixing of anchor point. In addition, the security of structures was researched to some extent.(5) Estimating the design concept of LCPBT design in turnout area on LeiDa bridge, and performing mechanical calculation, structural design as well as optimization of some components.According to the structural characteristics of LCPBT system, some design values were researchful confirmed, including reasonable mutual location between turnout and bridge, arrangement form of bridge bearing as well as length of rub plate. Some structural design advices were put forward which might be helpful in industrial design. Force check-calculations were carried out for prefabricated slab, subbase place, slip membrane, foam plate and fixation point. Based on the author’s study chance in Germany, the indoor test results of friction coefficient and durability of the slip membrane as well as durability of foam plate were researched, and some structural optimization measures were put forward, for instance, installation mode of beam crevice, anchor point and material of slip membrane.