摘要
动三轴试验是当今世界研究道床特性的最重要方法之一。通过动三轴试验 ,可研究荷载状态、道碴材质与级配以及道床状态对道床累积变形和道床弹性的作用 ,道床累积变形和道床弹性分别是道床由计划维修向状态维修过渡和轨道结构仿真参量的依据。基于动三轴试验 ,本文研究了试验前后道碴级配变化、道床累积变形和变形率以及道床弹性随荷载作用次数的变化规律 ,探索了道碴磨耗特性随重复荷载和材质的变化规律 ,得到了道床累积变形及变形率在试验开始时较大 ,随着荷载作用次数增大而减小 ,最后达到稳定的规律 ;道床弹性随荷载作用次数的变化规律也是如此 ,估算了道床最终稳定时的弹性模量 ,且有道床弹性仅是道碴材质的固有特性 ,受荷载作用次数和道床状态影响较小的结论。基于动三轴试验结果 ,对国外现有的道床累积变形模型进行了对比分析 ,并研究了各自的特点。
The dynamic triaxial test is one of the most important methods all over the world,which is used in studying ballast character.By the dynamic triaxial test,the effects of load status,ballast material and ballast grading,ballast status to ballast accumulated deformation and ballast elastic modulus are studied,which are the basements of parameters for dynamic emulation of track structure and for changing ballast time plan maintenance into ballast status maintenance. Based on the dynamic triaxial test,this paper studies the variable rule of pre test ballast grading and post test ballast grading,accumulated deformation and accumulated deformation rate with the load number,and ballast elastic modulus with load number.Therefore the characters of ballast abrasion with repeat load number and ballast material are found.A rule of the ballast accumulated deformation and its rate are concluded,whose values are big at the beginning of the test,smaller and smaller with load number,and become constant value at last,which is ballast modulus with load number as ballast accumulated deformation and its rate.The ballast elastic modulus is estimated at the last stable status,which is an intrinsic attribute of ballast material with little affect of load number and ballast status. Based on the results of dynamic triaxial test,the extant international ballast accumulated deformation modulus are compared and analyzed,whose characters are researched.The first step of the studying on ballast accumulated deformation and ballast elastic modulus has begun in our country.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2001年第2期101-106,共6页
China Railway Science
基金
铁道部科技研究开发计划项目! (98G3 1)
