基于界面黏结的含根土抗剪强度极限值估算模型  

Estimation model of limit values of shear strength of root-bearing soil based on interface bonding

作　　者：夏鑫 姜元俊[1] 苏立君[1] MEHTAB Alam 李佳佳 XIA Xin;JIANG Yuan-jun;SU Li-jun;MEHTAB Alam;LI Jia-jia(Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu,Sichuan 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Water Conservancy and Hydropower Engineering,Sichuan Agricultural University,Yaan,Sichuan 625014,China)

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,四川成都610041 [2]中国科学院大学,北京100049 [3]四川农业大学水利水电学院,四川雅安625014

出　　处：《岩土力学》2021年第8期2173-2184,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41761144077);中国科学院战略性先导科技专项(A类)(No.XDA23090202)。

摘　　要：目前根系力学固土定量评估模型中缺乏对根-土界面黏结作用的考虑,为提高量化模型精度及适用性,以广泛应用的Wu模型为基础,结合含根土中根系的破坏模式,通过界面黏结强度参数量化根-土界面间的黏结作用,建立了基于界面黏结的含根土抗剪强度极限值估算模型,考虑了含根土中土体应力、根径、根长、根系与剪切方向初始夹角的影响。含根土直剪试验的实测结果均在估算模型计算值范围内,其中根系与剪切方向夹角为45°时实测值接近模型计算最大值,夹角为90°时实测值接近模型计算极限值的平均值。与Wu模型计算值相比,估算模型精度平均提高了5倍。模型参数敏感性分析表明,根系提供的土体附加强度受根系数量参数、尺寸参数及界面黏结强度参数的影响较大。At present,the quantitative evaluation models of mechanical reinforcement of soil by roots lack consideration of root-soil interface bonding effect.In order to improve the accuracy and applicability of the quantitative model,this study was premised on the widely used Wu model,combined with the failure mode of root system in root-soil,and quantified the bonding effect of interface between root and soil interface by interface bonding strength parameters.Thus,an estimation model of limit values of shear strength of root-bearing soil based on interface bonding was established,which considered the influence of soil stress,root diameter,root length,and initial angle between root and shear direction in root-bearing soil.Furthermore,the comparison of shear strength of root-bearing soil between the measured values of direct shear test and the calculated values of the model showed that the measured values were within the range of the calculated values of the model established in this article.When the angle between the root and the shear direction was 45°,the measured value was close to the maximum value of the model calculation,and when the angle was 90°,the measured value was close to the average value of the limit values of the model calculation.Compared with the calculated value of Wu model,the accuracy of the estimation model established in this article was increased by five times on average.Moreover,the sensitivity analysis of model parameters showed that the additional soil strength provided by roots was greatly affected by the root number parameters,root size parameters and root-soil interface bond strength parameters.

关 键 词：含根土 根-土界面黏结强度 抗剪强度 力学模型 

分 类 号：TU43[建筑科学—岩土工程]