冻融循环作用下路基黏土的变形特性评价:室内试验及预估模型
Evaluation on deformation behavior of subgrade clay under freeze-thaw cycles:Laboratory tests and evolution model
冯介玺 1何忠明 1黄超 2刘正夫 1谢唐新1
作者信息
- 1. School of Traffic and Transportation on Engineering,Changsha University of Science&Technology,Changsha 410004,China
- 2. School of Civil Engineering,Central South University,Changsha 410075,China
- 折叠
摘要
路基土的变形特性对路基结构设计和路面耐久性保持十分重要.回弹模量(MR)和永久变形(PD)是分别表征路基土弹塑性变形的重要指标.本文旨在通过动三轴试验探究路基黏土在偏应力、围压、含水率、加载次数及冻融循环次数条件下的变形特性演变规律.结果表明:冻融循环次数对MR和PD的影响显著,且其在第1次冻融循环中衰减幅度最大,在第6次冻融循环中衰减趋于稳定.同时,在前2000次加载过程中,MR迅速衰减而PD急剧增加.提出并验证了一个综合考虑偏应力、围压、含水率、加载次数及冻融循环次数影响的PD预估模型.研究结果可为路基黏土在冻融循环作用下的变形特性分析提供有效参考.
Abstract
The deformation behavior of subgrade soil is crucial to the design of subgrade structures and to maintaining the long-term performance of pavements.Resilient modulus(MR)and permanent deformation(PD)are important indices to characterize elastic deformation and plastic deformation of subgrade soils,respectively.This study aims to investigate the evaluation of deformation behavior(MR and PD)of subgrade clay under deviatoric stress,confining pressure,moisture content,loading cycles,and freeze-thaw(FT)cycles by repeated triaxial load test.An evolution model for calculating PD was proposed based on experimental data.The results showed that the influence of FT cycles on MR and PD was obvious.The largest damage and stable trend were in the first and sixth FT cycles,respectively.MR decreases and PD increases rapidly during the first 2000 loading cycles.The PD evolution model consisting of deviator stress,confining pressure,moisture content,loading cycles and FT cycles of explicit modification functions was proposed and validated.The results obtained in this study contribute to a better understanding of the deformation behavior of subgrade clay under FT cycles.
关键词
路基土/循环加载三轴试验/变形特性/冻融循环/预估模型Key words
subgrade soil/repeated load triaxial test/deformation behavior/freeze-thaw cycles/evolution model引用本文复制引用
基金项目
National Natural Science Foundation of China(51978084)
National Natural Science Foundation of China(51678037)
Natural Science Foundation of Hunan Province,China(2020JJ4605)
Construction Project for Graduate Students of Changsha University of Science&Technology,China(CLSJCX22027)
出版年
2023
NETL
NSTL
维普
万方数据