摘要
聚氨酯固化道床可有效加强散体道床的整体性,固化后的碎石道砟体压缩性能是衡量改进效果的关键性指标。根据聚氨酯固化道床的结构及材料特点,制作立方体试件;通过单向及反复加压试验,研究自由边界下道砟体的压缩性能及变形规律。研究结果表明:单向压缩时试件的应力-应变曲线经过了刚度强化、稳定、衰减和破坏等4个过程;试件抵抗开裂的最大平均应力约为0.8 MPa。试件的耗能能力随着应力的增大而增强,随着反复荷载的次数增多而减小;当最大平均正压应力小于0.4 MPa时,反复加压后试件的残余应变能控制在0.01以内;超过0.4 MPa时,最大应变随荷载次数的增加仍有增大趋势。为保证聚氨酯固化道床运营的安全性和耐久性,道床所受的最大平均应力宜控制在0.4 MPa以下。
Polyurethane reinforced ballast bed can effectively strengthen the integrity of the ballast bed.The compression performance of the solidified ballast body is the key index to measure the improved effect.According to the structure and material characteristics of polyurethane reinforced ballast bed,the cube specimens were made.The compression performance and deformation of ballast body under free boundary were studied by unidirectional and repeated pressure tests.The results are as follows.The stress-strain curve of the specimen under unidirectional compression goes through four processes,which are stiffness strengthening,stability,attenuation and failure.The maximum average stress of the specimen against cracking is about 0.8 MPa.The energy dissipation capacity of the specimen increases with the increase of stress and decreases with the increase of the number of repeated loads.When the maximum average positive compressive stress is less than 0.4 MPa,the residual strain energy of the specimen after repeated pressure is controlled within 0.01.When the maximum strain exceeds 0.4 MPa,it still tends to increase with the increase of load times.In order to ensure the safety and durability of the operation of polyurethane reinforced ballast bed,the maximum average stress of ballast bed should be controlled below 0.4 MPa.
作者
余思昕
肖杰灵
景璞
杜帅
熊震威
YU Sixin;XIAO Jieling;JING Pu;DU Shuai;XIONG Zhenwei(MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;College of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2021年第5期1113-1120,共8页
Journal of Railway Science and Engineering
基金
国家自然科学基金高铁联合基金资助项目(U1734207)
四川省科技计划资助项目(2020YFG0125)
中铁第一勘察设计院集团有限公司科技开发计划资助项目(院科17-07)。
关键词
有砟轨道
聚氨酯固化道床
单轴压缩
反复加载
压缩性能
ballast track
polyurethane reinforced track bed
uniaxial compression
cyclic loading
compression performance
作者简介
通信作者:肖杰灵(1978−),男,湖南汨罗人,副教授,博士,从事高速、重载及城市轨道交通轨道结构及轨道动力学研究,E−mail:xjling@home.swjtu.edu.cn。
