摘要
为探究根段形态对小叶锦鸡儿根土界面摩阻特性和复合体抗剪强度特性的影响,针对小叶锦鸡儿直根段、带须根根段及分叉根段进行拉拔试验和根土复合体直剪试验,研究分叉角度、须根有无对小叶锦鸡儿根土界面摩阻特性和复合体抗剪强度特性的影响。结果表明:根段形态对小叶锦鸡儿根土界面摩阻特性、复合体抗剪强度和复合体黏聚力有较大影响,根段长度相同、平均根径为1.75mm的小叶锦鸡儿根土界面拉拔阻力和复合体抗剪强度均为:分叉根段(26.52N,36.62Kpa)>带须根根段(24.74N,25.14Kpa)>直根段17.97(N,19.74Kpa);对于径级范围在1.5-2mm内的分叉根段,根土界面拉拔摩阻强度、复合体抗剪强度均随分叉夹角的减小而降低:60-90°(57.87Kpa,36.32Kpa)>30-60°(53.44Kpa,26.73Kpa)>0-30°(46.54Kpa,25.14Kpa);复合体黏聚力和内摩擦角的变化规律亦然:60-90°(15.54Kpa,22.13°)>30-60°(13.81 Kpa,20.59°)>0-30°(12.75 Kpa,18.86°)。须根能够提高根系固土效果,分叉角较大的根段在固土护坡效果上优于夹角较小的根段。
The arm of the research is to explore the influence of root morphology on the friction and strength of root-soil composite in Caragana korshinskii.The pull test and direct shear test on root-soil composite were carried out for the straight root,root with fibrous roots and bifurcated root segments of C.microphylla,and the effects of bifurcation angle and fibrous root on the root-soil interface friction characteristics and shear strength characteristics of the composite were studied.The results show that the root morphology affects the friction properties,composite shear strength,composite cohesion and friction angle of the soil.Both the interface tensile resistance and the shear strength of the composite with an average root diameter of 1.75 mm are:bifurcated root(26.52 N,36.62 Kpa)>root with fibrous roots(24.74 N,25.14 Kpa)>straight root(17.97 N,19.74 Kpa).For the bifurcated root segments with a diameter range of 1.5-2 mm,the impaction resistance strength and the composite shear strength at the root-soil interface all decrease with the reduction of the bifurcation angle:60-90°(57.87 Kpa,36.32 Kpa)>30-60°(53.44 Kpa,26.73 Kpa)>0-30°(46.54 Kpa,25.14 Kpa).The change of the composite cohesion and internal friction angle:60-90°(15.54 N,22.13°)>30-60°(13.81 N,20.59°)>0-30°(12.75 N,18.86°).The fibrous root can improve the effect of root consolidation,and the root section with larger bifurcation angle is better than the one with smaller angle in solid slope protection.
作者
袁亚楠
刘静
李诗文
张欣
胡晶华
刘泉
王丫博
YUAN Yanan;LIU Jing;LI Shiwen;ZHANG Xin;HU Jinghua;LIU Quan;WANG Yabo(College of Desert Contral Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010019;Institute of Water Resources for Pasturing Area of the Ministry of Water Resources,Hohhot 010010;Water Conservancy Bureau of Aohan Country,Chifeng 024300,China)
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2022年第7期173-179,共7页
Journal of Arid Land Resources and Environment
基金
内蒙科技计划项目(201802107)资助。
关键词
根段形态
根土复合体
抗剪强度
摩阻特性
root morphology
root-soil composite
shear strength
friction characteristics
