考虑道砟嵌入作用的有砟轨道基床表层变形行为研究  

Study on Deformation Behaviors of Subgrade Bed Surface Layer in Ballast Tracks Considering Ballast Penetration

作　　者：聂如松[1,2] 李亚峰 冷伍明[1,2] 黄茂桐 周思危 董俊利 NIE Rusong;LI Yafeng;LENG Wuming;HUANG Maotong;ZHOU Siwei;DONG Junli(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;School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232000,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学重载铁路工程结构教育部重点实验室,湖南长沙410075 [3]安徽理工大学土木建筑学院,安徽淮南232000

出　　处：《铁道学报》2023年第11期128-137,共10页Journal of the China Railway Society

基　　金：国家自然科学基金(51878666,51978672,52308335);安徽省项目高校科研项目(2023AH051170);安徽理工大学引进人才科研启动基金(2022yjrc75);中国铁路太原局集团有限公司技术合作开发项目(A2020G02);高速铁路建造技术国家工程实验室开放基金(HSR201905)。

摘　　要：为研究有砟轨道道砟嵌入现象及其对基床表层变形行为的影响,开展以道砟碎石-基床粉土双层试样为研究对象的动三轴试验,分析道砟嵌入对基床表层变形行为的影响,探讨基于道砟嵌入指标的基床表层变形行为标准。试验结果表明,道砟嵌入使得道砟碎石-基床粉土试样的粉土表层出现道砟槽痕并发生侧向变形,同时承受动荷载的能力降低;提高动应力水平和增加粉土含水率会加剧道砟嵌入程度;道砟碎石-基床粉土试样的破坏模式可分为剪切破坏型和软化破坏型;基床粉土含水率较低时,道砟碎石-基床粉土试样整体变形主要源于道砟和粉土的压缩变形,而当粉土含水率较高时,道砟嵌入引起的轴向和侧向变形则较为显著;当粉土处于最优含水率时,道砟嵌入速率为2.9×10^(-5) mm/s时道砟碎石-基床粉土试样达到塑性安定极限,而当粉土处于天然含水率和饱和含水率时,塑性安定极限对应的道砟嵌入速率则为1.4×10^(-4) mm/s。Based on the double-layered sample consisting of ballast particles and subgrade soil,a series of dynamic triaxial tests were carried out to study the ballast penetration and the resulting deformation behavior of subgrade surface layer in ballast tracks and to explore the influence of ballast penetration on the deformation behavior and failure patterns of the subgrade surface layer.The failure criterions of the ballast-soil samples were defined based on the ballast penetration rate.The research results show that the ballast penetration induces ballast pockets and lateral deformation of the silty soil and reduces the ability of the sample to resist dynamic loading.The increase in dynamic stress level and subgrade moisture content aggravates the ballast penetration degree.The failure patterns of ballast-soil samples can be divided into shear failure and softening failure.The deformation of the ballast-soil sample is mainly caused by the compression of ballast and soil at the low moisture content of silty soil.The deformation caused by ballast penetration is significant when the moisture content of silty soil is high.For silty soil with optimal moisture content,the plastic stability limit represented by the ballast penetration rate is 2.9×10^(-5) mm/s,and this index changes to be 1.4×10^(-4) mm/s for the samples with natural and saturated moisture content.

关 键 词：道砟嵌入 动三轴试验 基床表层 变形行为 塑性安定极限 

分 类 号：TU431[建筑科学—岩土工程] U213.7[建筑科学—土工工程]