摘要
大跨长联桥上无缝线路由于受温度力、制动力等附加力影响,梁轨之间频繁产生相对伸缩位移,导致梁端位置扣件轨下垫板窜出。为了研究轨下垫板窜出对小阻力扣件纵向阻力的影响,以WJ-8型小阻力扣件为例,分析轨下垫板窜出时的状态,将影响因素总结为垫板受力面积减小和垫板挡肩受钢轨与铁垫板挤压2个方面。据此,分别开展无挡肩垫板扣件和有挡肩垫板扣件在不同扭矩及垫板窜出量下的纵向阻力室内试验,通过将垫板挡肩去除,研究垫板受力面积减小对扣件纵向阻力的影响,并与正常垫板扣件试验进行对比,研究挡肩受挤压对扣件纵向阻力的影响。试验结果表明:1)无挡肩垫板扣件试验结果表明,垫板受力面积减小会使扣件滑移阻力减少2.7%~5.6%,对扣件纵向滑移曲线的影响较小;2)垫板挡肩受挤压程度增大会显著改变扣件纵向滑移特征曲线及滑移点,挡肩受挤压稳定后会使扣件滑移阻力增大约24.9%~40.3%;3)不同垫板窜出量下,有挡肩垫板扣件纵向阻力明显大于无挡肩垫板扣件纵向阻力;在垫板挡肩挤压稳定后,前者纵向阻力值为后者的1.29~1.36倍;4)扣件滑移阻力-位移曲线与扣件安装扭矩正相关,拟合了有挡肩垫板扣件不同扭矩及垫板窜出量下纵向阻力-位移曲线的幂指数函数,为使小阻力扣件滑移阻力满足(4±1) kN的使用要求,现场发现扣件垫板窜出超过15 mm应及时复原或更换部件。研究成果可为无缝线路状态的预测计算及现场维护检修提供参考。
The continuously welded rail track on the long-span continuous bridge is subject to additional forces such as temperature and braking forces,resulting in frequent relative displacements between the beam and the track.This leads to the pad of the fasteners at the beam ends sliding.In order to study the influence of sliding pad on longitudinal resistance of fasteners,taking WJ-8 type small resistance fastener as an instance,the paper analyzed the fasteners state during pad slide.The influence factors were mainly reflected in the reduction of the force area of pad and the compression of the pad shoulder by rail and iron pad.Accordingly,indoor tests were conducted to measure the longitudinal resistance of rail fasteners with and without pad shoulder under different torques and different pad sliding displacement.By removing the shoulder from the pad,the impact of the reduced contact area on the longitudinal resistance of the fasteners was studied.These results were then compared with tests on standard fasteners with shoulder pad to investigate the effect of shoulder compression on the longitudinal resistance of the fasteners.Experimental results are drawn as follows.(1)For fasteners without pad shoulders,the reduction in force area of the pad leads to a decrease in sliding resistance of the fastener by 2.7%~5.6%,with a relatively minor impact on the longitudinal sliding curve of the fastener.(2)Compression of the pad shoulder significantly alters the longitudinal sliding characteristic curve and sliding point of the rail.After the pad shoulder is compressed stably,it increases the sliding resistance of the fastener by approximately 24.9%~40.3%.(3)With different pad sliding displacements,the longitudinal resistance of fasteners with shoulder pads is significantly greater than that of fasteners without shoulder pads.After the compression of the shoulder pads stabilizes,the longitudinal resistance of the former is 1.29~1.36 times that of the latter.(4)The power exponential function is fitted for the longitudinal resistance-displacement curve of fasteners with pad shoulders at different torques and different pad sliding displacement.In order to make the slip resistance of the small resistance fasteners meet the usage requirement of(4±1)kN,the fasteners should be recovered or replaced in time when the pad is found to have slid more than 15 mm.The research results can provide reference for the state prediction and maintenance of continuous welded rail.
作者
曾志平
刘卓
李沛成
王卫东
张志鹏
黄志斌
段廷发
ZENG Zhiping;LIU Zhuo;LI Peicheng;WANG Weidong;ZHANG Zhipeng;HUANG Zhibin;DUAN Tingfa(School of Civil Engineering,Central South University,Changsha 410075,China;MOE Key Laboratory of Engineering Structures of Heavy Haul Railway(Central South University),Changsha 410075,China;Dongnan Coastal Railway Fujian Co.,Ltd.,Fuzhou 350000,China;China Railway 12th Bureau Group Co.,Ltd.,Taiyuan 030024,China)
出处
《铁道科学与工程学报》
北大核心
2025年第5期2114-2125,共12页
Journal of Railway Science and Engineering
基金
中国铁路南昌局集团有限公司科技研究开发计划课题(202007)。
关键词
扣件系统
纵向阻力
垫板窜出
WJ-8型小阻力扣件
无缝线路
fastening system
longitudinal resistance
sliding of pad
WJ-8 small resistance fastener
continuous welded rail
