摘要
基于无砟轨道基床表层水力损伤病害产生机制,提出一种在基床表层上设置聚氨酯碎石防水联结层的水力损伤控制措施。通过建立级配碎石组(J-0)、透水型聚氨酯碎石组(J-5)及致密型聚氨酯碎石组(J-10)3组试验模型,研究聚氨酯碎石防水联结层的静动力特性、疲劳特性与防水特性。结果表明:静力加卸载作用下,J-10残余应变为2.6×10^(–6),最大位移约为1.0 mm,与下部基床表层级配碎石层变形适应性良好,耗能效果明显,在列车动力荷载水平作用下,可减小基床表层动变形与动应力幅值,增大动应力扩散范围;在长期动力循环荷载作用下,J-0与J-5在注水后结构层动力响应显著增大,而J-10动力响应在加载次数1~2万次后基本保持稳定;试验过程中J-10能够有效防止水分进入基床表层级配碎石层,而J-0与J-5水分不断下渗,引起级配碎石细颗粒损失。研究成果对整治多雨地区无砟轨道基床表层水力损伤病害具有重要的应用价值。
Based on the mechanism of hydraulic damage of the surface layer of ballastless track subgrade bed,a hydraulic damage control measure of setting polyurethane crushed stone waterproof bonding layer on the surface layer of subgrade bed is proposed.By establishing three groups of test models of graded crushed stone group(J-0),permeable polyurethane crushed stone group(J-5)and dense polyurethane crushed stone group(J-10),the static and dynamic characteristics,fatigue characteristics and waterproof characteristics of polyurethane crushed stone waterproof bonding layer are studied.The results show that the residual strain of J-10 is 2.6×10^(–6)under static loading and unloading,and the maximum displacement is about 1.0 mm.It has a good deformation adaptability with the surface layer of the subgrade bed and an obvious energy consumption.Under the action of the train dynamic load,it can reduce the amplitude of dynamic deformation and dynamic stress on the surface of the subgrade bed and increase the expansion range of dynamic stress.Under the action of the long-term dynamic cyclic load,the dynamic response of structural layer of J-0 and J-5 increases significantly after water injection,while the dynamic response of J-10 remains basically stable after 10000–20000 times loading.During the test,J-10 can effectively prevent water from entering the crushed stone layer on the surface of the subgrade bed,while water continuously infiltrates in J-0 and J-5,causing the erosion of fine particles of graded crushed stone.The research work has an important application value for the treatment of hydraulic damage on the surface of ballastless track subgrade bed in rainy areas.
作者
谢康
苏谦
陈晓斌
刘宝
王武斌
王迅
邓志兴
XIE Kang;SU Qian;CHEN Xiao-bin;LIU Bao;WANG Wu-bin;WANG Xun;DENG Zhi-xing(School of Civil Engineering,Central South University,Changsha,Hunan 410075,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610003,China;China Railway Design Corporation,Tianjin 300308,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第8期2308-2317,共10页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51978674)
中国铁道科学研究院集团重点课题(No.2020YJ143)
中国铁路设计集团重点课题(No.2020YY240606)
中南大学研究生创业计划(No.2022ZZTS0622)。
关键词
无砟轨道
模型试验
水力损伤
聚氨酯碎石
防水联结层
ballastless track
model test
hydraulic damage
polyurethane crushed stone
waterproof bonding layer
