Effects of loading rate on root pullout performance of two plants in the eastern Loess Plateau,China  

作　　者：ZHANG Chaobo LI Rong JIANG Jing YANG Qihong 

机构地区：[1]College of Water Resources Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China [2]Key Laboratory of the Regulation and Flood Control of Middle and Lower Reaches of the Changjiang River under Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China

出　　处：《Journal of Arid Land》2023年第9期1129-1142,共14页干旱区科学（英文版）

基　　金：supported by the Natural Science Foundation of Shanxi Province of China(20210302123105);the Shanxi Scholarship Council of China(2020-054);the Changjiang River Scientific Research Institute(CRSRI)Open Research Program(CKWV20221006/KY).

摘　　要：Root pullout performance of plants is an important mechanical basis for soil reinforcement by plant roots in the semi-arid areas.Studies have shown that it is affected by plant factors(species,ages,root geometry,etc.)and soil factors(soil types,soil moisture,soil bulk densities,etc.).However,the effects of loading rates on root pullout performance are not well studied.To explore the mechanical interactions under different loading rates,we conducted pullout tests on Medicago sativa L.and Hippophae rhamnoides L.roots under five loading rates,i.e.,5,50,100,150,and 200 mm/min.In addition,tensile tests were conducted on the roots in diameters of 0.5-2.0 mm to compare the relationship between root tensile properties and root pullout properties.Results showed that two root failure modes,slippage and breakage,were observed during root pullout tests.All M.sativa roots were pulled out,while 72.2%of H.rhamnoides roots were broken.The maximum fracture diameter and fracture root length of H.rhamnoides were 1.22 mm and 7.44 cm under 100 mm/min loading rate,respectively.Root displacement values were 4.63%(±0.43%)and 8.91%(±0.52%)of the total root length for M.sativa and H.rhamnoides,respectively.The values of maximum pullout force were 14.6(±0.7)and 17.7(±1.8)N under 100 mm/min for M.sativa and H.rhamnoides,respectively.Values of the maximum pullout strength for M.sativa and H.rhamnoides were 38.38(±5.48)MPa under 150 mm/min and 12.47(±1.43)MPa under 100 mm/min,respectively.Root-soil friction coefficient under 100 mm/min was significantly larger than those under other loading rates for both the two species.Values of the maximum root pullout energy for M.sativa and H.rhamnoides were 87.83(±21.55)mm•N under 100 mm/min and 173.53(±38.53)mm•N under 200 mm/min,respectively.Root pullout force was significantly related to root diameter(P<0.01).Peak root pullout force was significantly affected by loading rates when the effect of root diameter was included(P<0.01),and vice versa.Except for the failure mode and peak pullout

关 键 词：plant roots soil reinforcement loading rate root pullout properties root-soil interaction loess area 

分 类 号：S152[农业科学—土壤学]