摘要
以种植于西宁盆地自建试验区生长期为2 a的灌木植物柠条锦鸡儿(Caragana korshinskii Kom.)、霸王(Zygophyllum xanthoxylon Maxim.)为试验供试种,采用扫描电镜观察方法,分析了这2种灌木根表面、与根接触土体表面、未与根接触土体表面的微观结构特征及其对根–土界面摩擦特性的影响。在此基础上,通过单根拉拔试验定量评价2种灌木根–土界面静摩擦因数和单位面积摩擦阻力。扫描电镜观察试验结果表明,柠条锦鸡儿根表面粗糙程度相对高于霸王;与2种灌木根接触土体表面均表现出相对平整和致密的特征;未与根接触土体表面则表现出凹凸不平和粗糙多孔状的特征。灌木根生长过程中对与其接触的土体表面存在平整化作用,平整化后的与根接触土体表面粗糙度显著降低,故根–土界面摩擦特性主要取决于根表面粗糙程度。单根拉拔试验结果进一步表明,柠条锦鸡儿较霸王具有相对更为显著的根–土界面静摩擦因数(分别为0.74±0.03和0.56±0.04)和根–土界面单位面积摩擦阻力(分别为22.94±1.15 kPa和17.26±1.36 kPa)。研究结果为进一步探讨寒旱环境条件下西宁盆地黄土区植物根–土相互作用力学机制,以及科学、有效地防治研究区和与区内自然条件相类似的其他地区,水土流失、浅层滑坡等地质灾害的发生具有理论研究价值和实际指导意义。
Two 2-year-old shrubs Caragana korshinskii Kom. and Zygophyllum xanthoxylon Maxim.,which were planted in the testing area,were selected as the research objects. The scanning electron microscope（SEM） was applied to analyze the microstructural features of root surface,soil surface contacting the roots and soil surface notin touch with the roots,and to investigate their influence on the friction characteristics of the root-soil interface. The pull-out test of a single root was carried out to quantitatively evaluate the static friction coefficient and the friction resistance per unit area of the root-soil interface of two shrubs. The results of scanning electron microscope reveal that the roughness degree of root surface of C. korshinskii is higher than that of Z. xanthoxylon,that the soil surfaces contacting the roots of both shrubs are relatively flat and dense and that the soil surface not in touch with the roots is rough and porous. The soil surfaces contacting the roots can be flattened by the roots during the growth process so that the roughness degree of the soil surface contacting the roots is significantly reduced,which shows that the friction characteristics of the root-soil interface depend mainly on the roughness degree of the root surface. The results of pull-out test of a single root show that the static friction coefficients of root-soil interface of the roots of C. korshinskii and Z. xanthoxylon are 0.74±0.03 and 0.56±0.04 respectively and that the friction resistances per unit area of root-soil interface of C. korshinskii and Z. xanthoxylon are 22.94±1.15 k Pa and 17.26±1.36 kP a respectively,which reflects that the former has a more significant friction resistance per unit area between root and soil.
作者
刘亚斌
胡夏嵩
余冬梅
李淑霞
杨幼清
LIU Yabin1, 2, 3, HU Xiasong1, 4 ,YU Dongmei1,2, LI Shuxia1,2, 3 YANG Youqing1, 2, 3(1. Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008, China; 2. Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes, Xining, Qinghai 810008, China; 3. University of Chinese Academy of Sciences, Beijing 100049, China; 4. Department of GeologieaI Engineering, Qinghai University, Xining, Qinghai 810016, Chin)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第5期1270-1280,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
青海省自然科学基金资助项目(2014–ZJ–906)
国家自然科学基金资助项目(41572306)
中国科学院"百人计划"资助项目(Y110091025)~~
关键词
土力学
西宁盆地
黄土区
根–土界面微观结构
拉拔试验
摩擦特性
soil mechanics
Xining Basin
loess area
root-soil surface microstructure
pull-out test
friction characteristics
