【作者】 范生波；

【导师】 罗强；

【作者基本信息】 西南交通大学 ， 道路与铁道工程， 2010， 硕士

【摘要】 高速列车行驶时无砟轨道-路基的相互动力作用是当前科学研究的一个热点问题,而现场动响应测试是揭示其真实作用规律的主要技术手段之一,是理论模型合理性验证的重要环节,也是开展动力学性能评价的基础。论文通过现场实车试验,测试无砟轨道路基系统在列车速度≥300km／h范围内的动响应幅值大小和分布规律,研究了混凝土结构层和路基基床在列车荷载下的动态特性,通过对测试数据的整理和分析得到了如下的初步成果：(1)通过对京津高铁和武广高铁土质路基上的CRTSⅡ型、CRTSⅠ型板式轨道结构在不同行车速度下动响应测试,数据统计分析表明,层状构造的混凝土结构发挥了对动荷载的支承和传递作用,纵向连接式的CRTSⅡ型板式轨道结构中从轨道板到路基面,动变形、振动加速度、振动速度分别衰减了77.5%、53.7%、70.2%；而间断式的CRTSⅠ型中衰减为58.06%、82.2%、41.7%,动响应衰减明显。(2)实测数据表明,板式轨道路基基床表面动应力(支承层下)横向呈马鞍形分布；基床动应力垂向沿着基床深度衰减明显,在距离路基表面0.4m、0.9m、1.5m、2.1m深度处相应衰减系数为0.71、0.57、0.52、0.32。基床表面(支承层下)振动加速度分布趋势是轨道板中心位置处大,支承层边缘小。路基面下2.7m相对基床表层振动加速度衰减了71.4%；基床表面振动速度在横向与振动加速度分布规律相似。(3)通过对实车测试数据的统计分析,得出列车轴重和速度在不同的结构部位对动响应影响效果不同,列车轴重对整个系统的振动变形、振动加速度、振动速度影响显著；而列车速度则对振动变形基本无影响,对基床动应力影响也不明显,对振动加速度和振动速度影响显著。(4)通过对实车测试数据的频域变换,得到信号功率谱,在频域内无砟轨道路基系统的振动位移信号的频率范围较窄,同时对列车速度的改变不敏感；而振动加速度信号频率范围较宽；振动速度信号的频率对列车速度改变敏感。更多还原

【Abstract】 Dynamic interaction between ballast track and subgrade under high speed train is a hot issue in current scientific research.Dynamic response field test is one of main technical means revealing the interaction law,an important step verificating rational of theoretical models,and a base carrying out dynamic performance evaluation.This paper bases on field test.In field test, the train speed is not less than 300km/h.Dynamic response’s amplitude and distribution in ballast track’s each structure part were tested.Meanwhile,the external characteristics of concrete layer and subgrade were investigated.Based on test data,researches and conclusions are as follows:(1) Dynamic response in two types of slab track structure (CRTSⅡtype and CRTS I type) were tested under different speed used in Beijing-Tianjin inter-city rail and Wuhan-Guangzhou passenger-dedicated line.The test results indicated that concrete structure in layer played a role in dynamic force’s bearing and transmission.Within CRTSⅡtype,dynamic deformation is decreased by 77.5%,dynamic acceleration 53.7%, dynamic velocity 70.2% from orbital plate to subgrade surface.While within CRTS I type, ynamic deformation is decreased by 58.06%,dynamic acceleration 82.2%, dynamic velocity41.7% from orbital plate to subgrade surface.(2) Transverse distribution of dynamic stress in subgrade surface is saddle-shape under slab track.Dynamic stress is decreased obviously in vertical direction. Transverse distribution of dynamic acceleration in subgrade surface is "larger in the middle,smaller in both sides".Dynamic acceleration is decreased by 71.4% from subgrade surface to 2.7m under it.Transverse distribution of dynamic velocity is similar to dynamic acceleration.(3) Axle load and speed’s influences on dynamic response of each structure part are different.Axle load’s influence on dynamic responses including deformation, acceleration and velocity of track-subgrade system are obvious.While train speed’s influences on dynamic deformation and stress are not apparent.(4) Through frequency transformation of test data,signal power spectrum was got.In frequency domain,dynamic deformation’s frequency coverage is small and not sensitive with train speed;dynamic acceleration’s frequency coverage is large and main stage frequencies vary with train speed;dynamic velocity’s main stage frequencies are sensitive with speed and increase exponentially.更多还原