岩土力学2024，Vol.45Issue(8)：2221-2231,2241,12.DOI:10.16285/j.rsm.2023.1535
基于电阻的冻结砂砾土孔隙冰压融效应研究
A resistivity-based study on the pressure melting of pore ice in frozen gravel soil
摘要
Abstract
To investigate the presence of pressure melting during the compression of frozen gravel soil,we conducted unconfined compression tests and resistance tests on gravel soil samples with varying water(ice)contents and freezing temperatures.The unfro-zen water content in saturated gravel soil samples was quantified using nuclear magnetic resonance(NMR)spectroscopy.The results indicate that:(1)During compression,the resistance of gravel soil initially decreased rapidly,subsequently slowing down,with only the dry sample exhibiting an increase in resistance post-peak stress.(2)In the rapid reduction stage,the resistance reduction rate of dry samples was lower compared to saturated frozen samples.Specifically,the resistance reduction rate of-4 ℃ saturated samples was 26.8％,which was fourfold that of dry samples at the same temperature.(3)As the freezing temperature decreased,the rate of resistance reduction initially increased and subsequently decreased during the rapid reduction stage.(4)Upon temperature reduction,the relative contents of both free water and capillary water underwent rapid declines,whereas the relative content of adsorbed water initially increased marginally before gradually decreasing.Analysis reveals that the compression of frozen gravel soil elicits a pres-sure melting effect,resulting in an increase in unfrozen water content within the high-stress regions of the sample during loading.This meltwater subsequently migrates through the unfrozen water film into the pore spaces of low-stress areas,where it re-freezes,altering the pore structure.Notably,the pressure melting effect is most pronounced within the temperature range of-2 ℃ to—4 ℃.关键词
冻结砂砾土/压融效应/无侧限压缩试验/电阻/导电路径Key words
frozen gravel soil/pressure melting effect/unconfined compression test/electrical resistance/conductive paths分类
建筑与水利引用本文复制引用
贾海梁,王亚彪,魏尧,胡彬华,金龙,董元宏,唐丽云..基于电阻的冻结砂砾土孔隙冰压融效应研究[J].岩土力学,2024,45(8):2221-2231,2241,12.基金项目
国家自然科学基金(No.42271148) （No.42271148）
中国交建应用基础研究项目(No.2021-ZJKJ-PTJS02) （No.2021-ZJKJ-PTJS02）
极端环境绿色长寿道路工程全国重点实验室开放基金(No.YGY2021KFKT02).This work was supported by the National Natural Science Foundation of China(42271148),the China Transportation and Construction Applied Basic Research Project(2021-ZJKJ-PTJS02)and the National Key Laboratory of Green Long-life Road Engineering in Extreme Environment Project(YGY2021KFKT02). （No.YGY2021KFKT02）
