摘要
结合北京—张家口高速铁路联调联试,针对0.6m厚级配碎石上覆0.1m厚沥青混凝土的新型基床表层结构(AC基床),开展试验车速在10~295km/h范围的有砟轨道路基动力响应测试,分析路基面动应力、动位移、振动加速度和振动速度随车速的变化规律,与邻近位置0.7m厚级配碎石强化基床表层结构(GW基床)比较的基础上,系统评价基床结构的动力性能。试验表明:随车速提高,反映基床动力作用的动应力、动位移近似线性增加,表征振动特性的振动加速度、振动速度呈折线形加速增大趋势;行车速度超过200km/h后,受1/3倍频程谱的低频范围加速度级VAL升高影响,AC基床路基面振动加速度高于GW基床;基于动应力和振动位移响应,运用归一化和基线修正技术,所得路基面动位移时程曲线能较好反映列车作用加卸载过程;路基面动力响应均低于控制限值,限值比Rx在0.16~0.82范围,基床结构的长期动力稳定性良好。
An in situ examination of a novel roadbed structure,consisting of a 0.6 m-thick graded gravel layer topped with a 0.1 m-thick asphalt concrete(AC roadbed),was conducted on the Beijing-Zhangjiakou high-speed rail to assess its dynamic properties under traveling speeds ranging from 10 to 295 km/h.This assessment involved an analysis of train-induced stress,deflection,acceleration,and velocity on the roadbed as a function of traveling speed.A comparison was made with an adjacent test section built with 0.7 m-thick graded gravel(GW roadbed)to systematically evaluate the dynamic performance of both roadbed structures.Test results reveal that stress and deflection,as measures of roadbed dynamic action,increase linearly with rising traveling speeds.In contrast,acceleration and velocity,as indicators of vibration characteristics,exhibit growth at an increasing rate with elevated traveling speeds.When traveling speeds surpass 200 km/h,the vibration acceleration of the AC roadbed exceeds that of the GW roadbed due to an increase in vibration acceleration levels(VALs)within the low center frequency range of 1/3 octave bands.Employing normalization and baseline correction techniques on the collected stress and displacement data,time histories of deflection that accurately represent the roadbed's loading and unloading processes caused by moving train loads were obtained.The indices pertaining to the dynamic performance of the roadbeds fall below the corresponding limit values,with limit ratios ranging from 0.16 to 0.82,signifying satisfactory long-term dynamic performance for both roadbed structures.
作者
冯桂帅
罗强
张良
谢宏伟
王腾飞
Feng Guishuai;Luo Qiang;Zhang Liang;Xie Hongwei;Wang Tengfei(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of High-speed Railway Engineering of the Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2023年第7期168-179,共12页
China Civil Engineering Journal
基金
国家自然科学基金(52078435,41901073)
四川省科技计划(2021YJ0001)。
关键词
高速铁路
有砟轨道
沥青混凝土
基床结构
动力响应
high-speed railway
ballasted track
asphalt concrete
roadbed structure
dynamic response
