寒冷地区CRTSⅢ型板式无砟轨道力学特性研究

发布时间：2018-06-23 23:51

本文选题：寒冷地区 + CRTSⅢ　；参考：《北京交通大学》2014年硕士论文

【摘要】：摘要：CRTSIII型板式无砟轨道是具有我国完全自主知识产权的新型无砟轨道结构形式,也是目前最具发展空间的无砟轨道结构形式之一。2013年9月开通运营的盘-营客运专线,是我国首条位于寒冷地区的采用CRTSIII型板式无砟轨道系统的客运专线,而寒冷地区铺设无砟轨道必须面临低温、冻融等导致轨道结构受力状态恶化的诸多问题。因此,对寒冷地区CRTSIII型板式无砟轨道结构的受力特性进行研究则显得尤为必要。本文以盘-营客运专线的建设为背景,在理论分析的基础上,运用有限元软件ABAQUS建立相应的静、动力分析模型,对寒冷地区CRTSIII型板式无砟轨道力学特性进行了深入研究,具体如下： (1)针对寒冷地区气温低、温差大的特点,利用有限元软件ABAQUS,建立寒冷地区CRTSIII型板式无砟轨道静力分析模型。研究在不同类型温度荷载作用下,轨道结构的翘曲位移和应力分布以及配筋对轨道板温度效应的影响情况。结果表明：寒冷地区温度荷载作用下轨道结构的应力与变形较大,尤其是轨道板的受力状态较为不利,建议在寒冷地区铺设的CRTSIII型轨道板加强配筋设置,具体为：采用双层配筋并在轨道板中部加密纵向受力钢筋。 (2)建立轨道结构静力分析模型及车辆-轨道-路基耦合动力分析模型,对寒冷地区自密实混凝土出现伤损后,在列车荷载、列车荷载与温度荷载共同作用下,轨道结构的受力特性进行研究,进而提出对于寒冷地区自密实混凝土伤损破坏程度的限值,并通过动力分析对伤损限值的合理性进行了验证。结果表明：基于轨道结构强度确定的自密实混凝土伤损限值满足动力响应的要求。 (3)建立车辆-轨道-路基耦合动力分析模型,研究路基不均匀冻胀、融沉变形对轨道结构动力响应的影响规律,以及在路基出现不均匀冻胀与融沉变形时,采取列车限速行驶的有效性及可行性。结果表明：路基冻胀与融沉变形对车体及轨道结构动力响应的影响较大,尤其是导致了轨道结构动应力的迅速增长；在出现轻微冻胀与融沉变形时,采取降速措施可以起到减弱动力响应的作用,但是随着车速的继续降低,对动力响应的减弱作用趋于平缓,因此,只靠单纯降低车速并不能够起到更好的改善效果。
[Abstract]:Abstract: CRTSIII slab ballastless track is a new type of ballastless track with our country's independent intellectual property rights. It is also one of the most developed ballastless track structures, which is one of the main forms of ballastless track, which opened and operated in September,.2013, which is the first one in our country to adopt the CRTSIII type slab ballastless track system in the cold area. The ballastless track in the cold area must face the problems of low temperature and freezing thawing, which lead to the deterioration of the stress state of the track structure. Therefore, it is particularly necessary to study the stress characteristics of the CRTSIII type slab ballastless track structure in cold areas.
In this paper, based on the construction of the PDL, based on the theoretical analysis, the finite element software ABAQUS is used to establish the corresponding static and dynamic analysis model. The mechanical characteristics of the CRTSIII type slab ballastless track in cold areas are studied in detail, as follows:
(1) aiming at the characteristics of low temperature and large temperature difference in cold area, the static analysis model of CRTSIII type slab ballastless track in cold area is established by using the finite element software ABAQUS. The influence of the warpage displacement and stress distribution of the track structure and the influence of the reinforcement on the temperature effect of the track plate under different types of temperature load are studied. The results show that the cold is cold. The stress and deformation of the track structure under the temperature load of cold area is larger, especially the stress state of the track plate is more unfavorable. It is suggested that the CRTSIII type track plate which is laid in the cold area should be reinforced. The concrete is to use the double layer reinforcement and encrypt the longitudinal reinforced bar in the middle of the track plate.
(2) the static analysis model of track structure and the model of vehicle track subgrade coupled dynamic analysis are established. The stress characteristics of the track structure are studied under the joint action of train load, train load and temperature load in cold areas, and the damage process of self compacting concrete in cold areas is put forward. The limit value of the degree is verified by the dynamic analysis. The results show that the limit of the damage of the self compacting concrete based on the strength of the track structure satisfies the demand of the dynamic response.
(3) establish a vehicle track subgrade coupled dynamic analysis model to study the influence of subgrade uneven frost heave and thawing deformation on the dynamic response of the track structure, and the validity and feasibility of the train running at the speed limit when the subgrade appears uneven frost heave and thawing deformation. The results show that the Subgrade Frost heave and thawing deformation are on the car body and the rail. The dynamic response of the channel structure is greatly influenced, especially the rapid growth of the dynamic stress of the track structure. In the case of slight frost heave and thawing deformation, the speed reduction measures can play a role in weakening the dynamic response, but as the speed continues to decrease, the weakening effect of the dynamic response tends to be slow, so only by the simple reduction of the vehicle. Speed does not have a better effect.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U213.244

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