城际铁路桥上新型双块式无砟轨道力学特性

Mechanical Characteristics of New Twin-block Ballastless Track on Intercity Railway Bridge

研究目的:为优化城际铁路无砟轨道结构设计,本文提出一种桥上新型双块式无砟轨道结构。该结构采用单层道床板形式,同时配以新型角钢-双块式轨枕。通过建立桥上新型双块式无砟轨道空间耦合力学模型,分析典型荷载作用下轨道静力学特性与动力学响应。研究结论:(1)角钢-双块式轨枕与道床板连接良好,在承受荷载作用时,角钢、轨枕与道床板协同变形,且角钢和轨枕的受力均不超过其材料的极限强度;(2)新型双块式无砟轨道在承受列车荷载、温度梯度荷载及整体温度荷载作用时,道床板的受力及变形情况较好,结构强度满足城际铁路设计要求;(3)新型双块式无砟轨道可以给列车提供平顺稳定的运行面,列车动力响应较小,安全性与平稳性指标均小于限值;(4)单层无砟道床可以提供足够的支承刚度,钢轨垂向位移较小,且由于道床板与梁面连接紧密,道床板动力响应较小;(5)本研究结论可为城际铁路轨道结构的优化设计提供理论支撑。

Research purposes:To optimize the design of the ballastless track structure of intercity railway,a new type of twin-block ballastless track structure on a bridge was presented in this paper,which adopted the single layer track bed plate and was equipped with a new angle steel-double block sleeper.In this paper,a new coupling mechanical model for the double-block ballastless track was established,and the static characteristics and dynamic response of the track under typical loads were analyzed.Research conclusions:(1)The new angle steel twin-block sleeper and the track bed plate are well connected,and when bearing the load,the angle steel,sleeper,and track bed are deformed together,and the force of the angle steel and sleeper does not exceed the ultimate strength of the material.(2)When the new twin-block ballastless track is subjected to train load,temperature gradient,and overall temperature load,the stress and deformation of the track bed are better,and the structural strength meets the design requirements of intercity railway.(3)When the intercity railway adopts the new twinblock ballastless track,the track could provide a smooth and stable running surface for the train,the dynamic response of the intercity train is small,and the safety and stationarity indicators are less than the limit value.(4)The single-layer track bed will not cause much change in the stiffness of the rail-bridge system,the vertical displacement of the rail is small,and the dynamic response of the track bed plate is small because of the close connection between the track bed plate and the beam surface.(5)The research results can provide theoretical support for the optimal design of intercity railway track structures.