无砟轨道泡沫混凝土路基碎石夹层结构动力特性试验研究  

Experimental Study on Dynamic Characteristics of Crushed Stone Interlayer Structure of Foamed Concrete Subgrade for Ballastless Track

作　　者：冯学茂 黄俊杰[3] 陈成华 黄志超 卢洺宇 王鑫越 FENG Xuemao;HUANG Junjie;CHEN Chenghua;HUANG Zhichao;LU Mingyu;WANG Xinyue(School of Civil Engineering,Central South University,Changsha 410075,China;Guangxi Xinfazhan Communication Group Co.,Ltd.,Nanning 530029,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Guangxi Road Construction Engineering Group Co.,Ltd.,Nanning 530001,China)

机构地区：[1]中南大学土木工程学院,湖南长沙4100075 [2]广西新发展交通集团有限公司,广西南宁530029 [3]西南交通大学土木工程学院,四川成都610031 [4]广西路建工程集团有限公司,广西南宁530001

出　　处：《铁道学报》2024年第5期132-141,共10页Journal of the China Railway Society

基　　金：国家自然科学基金(52078434)。

摘　　要：为研究无砟轨道泡沫混凝土路基碎石夹层结构的动力特性和长期动力稳定性,建立夹层结构足尺试验模型,开展变频加载和循环加载试验。研究结果表明,在变频动载作用下,夹层结构的振动加速度、动位移和动土压力呈增大规律但无峰值出现,表明夹层结构未产生共振现象;为降低加载频率对比值系数的影响,建议采用底座板与路基面之间振动位移比值系数作为基床或级配碎石夹层对无砟轨道结构支承状态分析的判据。循环动载作用下,夹层结构的振动加速度、动位移和动土压力在加载至100万次后趋于稳定;相较传统土石填料路基,泡沫混凝土层能更好地均化上部荷载;经200万次动载作用后,试验模型总累积沉降为0.898 mm,碎石夹层的压缩变形占总累积沉降的82.9%。试验结果表明,在无砟轨道结构与泡沫混凝土层之间设置厚度为0.7 m的级配碎石夹层,可为线路提供平顺性和稳定性。In order to study the dynamic characteristics and long-term dynamic stability of crushed stone interlayer structure of foamed concrete subgrade of ballastless track,a full-scale test model for interlayer structure was established to carry out variable frequency loading and cyclic loading tests.The results show that the vibration acceleration,dynamic displacement and dynamic earth pressure of the interlayer structure increase without peak value under the action of variable frequency dynamic load,indicating no resonance in the interlayer structure.Furthermore,to reduce the influence of the loading frequency on the ratio coefficient,it was suggested that the vibration displacement ratio coefficient between the base slab and the subgrade surface should be used as a criterion for the analysis of the supporting state of the ballastless track structure by the subgrade bed or the graded crushed stone interlayer structure.Under the cyclic dynamic load,the vibration acceleration,dynamic displacement and dynamic earth pressure of the structure can be stabilized after being loaded to 1 million times.Compared with the traditional embankment filled with soil and rock,the foam concrete layer can better distribute the loads from above.After 2 million dynamic loads,the total cumulative settlement of the test model was 0.898 mm,with the compression deformation of the crushed stone interlayer accounting for 82.9%of the total cumulative settlement.The results of the tests show that setting a graded crushed stone interlayer with a thickness of 0.7 m between the ballastless track structure and the foamed concrete layer can provide smooth and stable foundation for the line.

关 键 词：级配碎石夹层结构 足尺试验模型 变频加载试验 循环加载试验 动力响应 长期动力稳定性 

分 类 号：U213.1[交通运输工程—道路与铁道工程]