【作者】 杨娜；

【导师】 张鸿儒；

【作者基本信息】 北京交通大学 ， 岩土工程， 2010， 硕士

【摘要】 地铁的抗震设计并不仅要保证结构的安全,而且要保证在地震时有一定的运行安全保证。在地震作用下,轨道产生的弯折、挠曲等变形、地震引起的震动幅值过大等,均可能使在上面行驶的列车脱轨造成事故。为了进行地震作用下列车安全性分析,本文主要从轨道结构在地震荷载下的变形和震动幅值等方面研究了地铁轨道的抗震计算问题。(1)假定整体道床轨道与隧道结构共同变形,提出了地震作用下轨道结构抗震验算的方法,并分析了地震动强度、不同土层及隧道结构对轨道变形的影响。结果表明,地震动强度是影响轨道变形的主要因素,结构或土层的影响较小。(2)以集中质量模型,建立了在地震作用下地铁轨道地震动响应和列车运行安全验算方法。分析了普通整体道床和不同减震道床轨道的地震响应特性。计算表明,轨下减震构件的弹性连接刚度阻尼越大,轨道的震动位移幅值越小,若是安装了减振器的轨道结构,轨道位移比没有安装时小1%左右。减振器不仅在日常使用中能减少列车行驶对轨道产生的振动,还能减轻地震荷载对轨道产生的冲击,抗震效果好。(3)为进一步分析地震作用下列车运行安全,建立了车轨耦合相互作用模型,直接计算车轮对轨道的横向和垂向力,用于计算脱轨系数,并验算列车轨道的抗震性能。最后为了说明前文中所述的计算方法,根据实际工程的资料给出了地震作用下轨道变形计算实例。更多还原

【Abstract】 Anti-seismic design on subway track is not a deeply researched subject internal, so this paper just brings forth a simplified calculating method to calculate the deformation of the track under seismic, and limits some deformation value coin with the cope. This paper starts from three sides when researched:simplify calculated methods by the lengthways of the tunnel; analysis on vibration of the track; analysis on vehicle-track dynamic interaction.(1) Track deformation analysis is assumed that track and tunnel structure is in common deformation, and make the displacement of the strata which the tunnel bottom in instead of the longitudinal deformation of the track when earthquake happened. Checking that what influence would different seismic intensity, strata and tunnel structure make to the deformation on above.(2) The reason for track vibration response analysis is that most subway structures are based on ballastless monolithic concrete bed, and the influence to track vibration comes from tie plate under track while the bed embed roadbed without elastic connection between them. Stiffness of the cushion decides deformation of the track. Another new shock absorption track structure such as floating slab structure, etc, is different from ordinary structure in damping effect because of the increase steel spring below ballast, so explained separately.(3) Vehicle-track dynamic interaction model. This is commonly used in orbit computation. The paper is mainly calculating influence from seismic to track structure, so it’s also increased earthquake on this model and analyzes its corresponding reaction. The three methods explain the specific action of the track under seismic from simple to hard, and give different limited conditions to different action results for checking. Any structural design methods are aimed at certain design goal, and different design goal is to achieve different requirements, therefore, this paper also puts forward corresponding track structure anti-seismic performance requirements to adapt to the seismic design methods.Finally to illustrate the former method, according to some actual project material lists the calculation process and explained in detail of the process. This is not in specific engineering calculation of its seismic response, but I hope the seismic design method of anti-seismic design of metro could play a role, which can reduce earthquake damage in a certain extent of underground rail transportation engineering.更多还原