水土保持研究2025，Vol.32Issue(4)：208-216,9.DOI:10.13869/j.cnki.rswc.2025.04.007
冻融作用对白家包滑坡狗牙根根土复合体强度影响研究
Research on the effect of freeze-thaw action on the strength of root-soil composite of Cynodon dactylon in the Baijiabao landslide
摘要
Abstract
[Objective]This study aims to investigate the effects of the coupling between root systems and freeze-thaw cycles on the mechanical properties of soil,enriching the theoretical basis for vegetation-based soil protection and slope reinforcement,and providing a reference for establishing a predictive analysis system for the stability of reservoir slopes.[Methods]Taking the root-soil composite of Cynodon dactylon,the dominant vegetation in the Baijiabao landslide area of the Three Gorges Reservoir,as the research subject,macro and micro physical and mechanical tests were conducted under freeze-thaw cycles.The study investigated the failure patterns and the pattern of changes in unconfined compressive strength of root-soil composites with different root contents under freeze-thaw cycles.[Results](1)Under freeze-thaw cycles,the root-soil composite exhibited typical plastic failure characteristics.As the number of freeze-thaw cycles increased,the failure pattern gradually shifted from plastic failure to brittle failure.(2)The sample underwent a compression process consisting of four stages:linear elasticity,elastoplasticity,failure,and residual.The strength of the root-soil composite in the four stages was higher than that of bare soil,indicating that the presence of roots significantly enhanced the resilience of the soil.(3)The residual strength difference between bare soil and the root-soil composite decreased with the increase in the number of freeze-thaw cycles,suggesting that the reinforcement effect of roots on the soil gradually weakened with an increase in freeze-thaw cycles.(4)The freeze-thaw degradation process of the root-soil composite could be categorized into three stages:rapid attenuation,slow attenuation,gentle stabilization.The degradation effect was most significant in the early stages of freeze-thaw action,with the strength reduction after two freeze-thaw cycles accounting for 33%of the total strength reduction.(5)A rapid evaluation method for overall freeze-thaw damage across slopes with different vegetation coverage rates was established based on the freeze-thaw damage degree index.[Conclusion]The root system of Cynodon dactylon,to some extent,mitigates freeze-thaw-induced damage to shallow soil layers in the Baijiabao landslide and enhances soil strength.However,the reinforcing effect of roots decreases as the number of freeze-thaw cycles increases.It is convenient and feasible to evaluate the freeze-thaw damage in shallow soil layers of the Baijiabao landslide by using freeze-thaw damage degree instead of the number of freeze-thaw cycles.关键词
环境工程/根土复合体/冻融循环/根系加固/植被覆盖率Key words
environmental engineering/root-soil composite/freeze-thaw cycles/roots reinforcement/vegetation coverage rate分类
建筑与水利引用本文复制引用
王瑞红,崔芸静,骆浩,王芳,包顺..冻融作用对白家包滑坡狗牙根根土复合体强度影响研究[J].水土保持研究,2025,32(4):208-216,9.基金项目
国家自然科学基金面上项目(51979151) （51979151）
湖北省自然科学基金杰青项目(2021CFA090) （2021CFA090）
三峡库区地质灾害教育部重点实验室开放资助项目(2020KDZ07) （2020KDZ07）
