Characteristics of root-permeated soil under simple-shear and direct-shear conditions  

作　　者：CHEN Jing-yi CHEN Xiao-qing SONG Dong-ri LV Ming GUO Han-qing SADEGHI Hamed 

机构地区：[1]Laboratory of Mountain Hazards and Earth Surface Process/Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Department of Civil Engineering,Sharif University of Technology,Tehran 1458889694,Iran

出　　处：《Journal of Mountain Science》2023年第8期2422-2435,共14页山地科学学报（英文）

基　　金：the financial supports from the National Natural Science Foundation of China(Grant No.41925030 and 4179043);the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,Grant No.2019QZKK0904);the Natural Science Foundation of Shaanxi Province(2020JQ-041)。

摘　　要：The simple-shear condition is closer to reality than the direct-shear condition for simulating the mechanical behavior of vegetated soil slope under shallow failure.However,study on simple-shear characteristics for vegetated slope is still insufficient,and there lacks intuitive comparison of characteristics between these two shear conditions.In this study,large-scale simple-shear and direct-shear experiments were conducted on soil permeated by roots of Amorpha fruticosa to investigate the shear strength and stiffness.The stress-displacement relationship of each sample was obtained and further normalized to unify the influence of root content.The results reveal that the direct-shear condition overestimates the shear strength of root-permeated soils(by 41%)and thus the estimation of slope stability based on the parameters of direct-shear condition is not conservative.Furthermore,the initial stiffness of root-permeated soil under simple-shear condition is 34%lower than that under direct-shear condition.The higher strength and stiffness under direct-shear condition are caused by the following reasons:the shear plane does not have the lowest strength,the shear area is decreasing,and the shear zone is thinner.The significant deformation(lower stiffness)revealed by the simple-shear condition facilitates the application of early warning for vegetated shallow landslides.

关 键 词：Simple-shear condition Direct-shear condition Root-permeated soil Shear strength Shear stiffness Shallow landslide 

分 类 号：TU41[建筑科学—岩土工程]