Abstract:[Background] The root system is the organ that directly contacts with the soil and has the function of supporting the plant and fixing the soil. In karst area, the soil layer is shallow, the soil erosion is serious, and the ecological environment is poor. With the development of economy, climate change, debris flow, landslides and other natural disasters occur frequently, the stability of slope soil has aroused widespread concern.[Methods] In order to study the mechanical characteristics of slope greening shrubs in karst area,taking 4-year-old Cassia bicapsularis and Indigofera amblyantha as the research objects, the root diameters were divided into four grades. Under the loading rate of 100 mm/min, the friction test between the root and soil was carried out by using a single root vertical pull-out method. The effects of root length, root surface interaction and root length on the soil were investigated. The soil bulk density and water content were 1.43 g/cm3 and 17.15%.[Results] 1) The root bark surface of C. bicapsularis had dense longitudinal cracks and formed notches, while the root bark surface of I. amblyantha was scaly. The root-soil friction coefficient of C. bicapsularis was higher than that of I. amblyantha, the root system of C. bicapsularis had better ability of strengthening soil strength and resisting deformation and failure than that of I. amblyantha. 2) In the process of friction between single drawing and soil interface, the characteristic curve of force displacement relationship experienced three stages:viscous friction stage, debonding friction stage and bonding friction stage.3) The friction force between the roots and soil of C. bicapsularis and I. amblyantha increased with the increase of burial depth. The longer the extension of vegetation roots in soil, the greater the role of force. 4) The root diameter of C. bicapsularis and I. amblyantha showed a significant positive correlation with their maximum friction, while with the change of diameter, there was no significant difference in the friction per unit area.[Conculsions] That is to say, the force released by a single root of C. bicapsularis in the pull-out friction test was greater than that of the latter, and it was better to enhance the soil strength and resist the deformation and failure. Therefore, it is suggested that C. bicapsularis should be used as vegetation slope protection. The results provide a theoretical basis for the selection of greening tree species, soil consolidation mechanism and prevention of shallow landslide in the study area.
郭欢, 陈龙, 唐丽霞, 潘露, 阮仕航. 喀斯特区2种护坡灌木单根拉拔摩擦试验[J]. 中国水土保持科学, 2022, 20(1): 128-135.
GUO Huan, CHEN Long, TANG Lixia, PAN Lu, RUAN Shihang. Experimental study on the pull-out friction of two kinds of slope protection shrubs in karst area. SSWC, 2022, 20(1): 128-135.
陈洪松,王克林.西南喀斯特山区土壤水分研究[J]. 农业现代化研究, 2008(6):734. CHEN Hongsong, WANG Kelin. Soil water research in Karst mountain areas of southwest China[J]. Agricultural Modernization Research, 2008 (6):734.
[2]
杨永红, 刘淑珍, 王成华, 等. 浅层滑坡生物治理中的乔木根系抗拉实验研究[J]. 水土保持研究, 2007,2(1):138. YANG Yonghong, LIU Shuzhen, WANG Chenghua, et al. A study of tensile strength tests of arborous species root system in forest engineering technique of shallow landslide[J]. Research of Soil and Water Conservation, 2007, 2(1):138.
[3]
PALLEWATTHA M, INDRARATNA B, HEITOR A, et al. Shear strength of a vegetated soil incorporating both root reinforcement and suction[J]. Transportation Geotechnics, 2019(18):72.
[4]
刘福全, 刘静, 瑙珉, 等. 植物枝叶与根系耦合固土抗蚀的差异性[J]. 应用生态学报, 2015, 26(2):411. LIU Fuquan, LIU Jing, NAI min, et al. Species-associated differences in foliage-root coupling soil-reinforcement and anti-erosion[J]. Chinese Journal of Applied Ecology, 2015, 26 (2):411.
[5]
吴鹏, 谢朋成, 宋文龙, 等. 基于根系形态的植物根系力学与固土护坡作用机理[J]. 东北林业大学学报, 2014, 58(5):139. WU Peng, XIE Pengcheng, SONG Wenlong, et al. Morphology-based plant root mechanics and function mechanism for slope stabilization[J]. Journal of Northeast Forestry University, 2014, 58(5):139.
[6]
易富, 张利阳. 土工格栅拉拔试验模型优化及加筋特性研究[J]. 安全与环境学报, 2020, 20(1):73. YI Fu, ZHANG Liyang. Approach to optimizing the pull-out test model of geogrid and the reinforcement features[J]. Journal of Safety and Environment, 2020, 20(1):73.
[7]
ZHOU Yue, D WATTS, LI Yuhui, et al. A case study of effect of lateral roots of Pinus yunnanensis on shallow soil reinforcement[J]. Forest Ecology & Management, 1998, 103(2/3):107.
[8]
SCHWARZ M, COHEN D Or D. Root-soil mechanical interactions during pullout and failure of root bundles[J]. Journal of Geophysical Research Atmospheres, 2010, 115(F4):701.
[9]
邢会文, 刘静, 王林和, 等. 柠条、沙柳根与土及土与土界面摩擦特性[J]. 摩擦学学报, 2010, 30(1):87. XING Huiwen, LIU Jing, WANG Linhe, et al. Friction characteristics of soil-soil interface and root-soil interface of caragana intermedia and Salix psammophila[J]. Tribology, 2010, 30(1):87.
[10]
宋维峰, 陈丽华, 刘秀萍. 根系与土体接触面相互作用特性试验[J]. 中国水土保持科学, 2006, 4(2):62. SONG Weifeng, CHEN Lihua, LIU Xiuping.Experimenton characteristic of interface between root system and soil[J]. Science of Soil and Water Conservation, 2006, 4(2):62.
[11]
郑力文, 刘小光, 陈丽华, 等. 油松根系直径对根-土界面摩擦性能的影响[J]. 北京林业大学学报, 2014, 36(3):90. ZHENG Liwen, LIU Xiaoguang, CHEN Lihua, et al. Effects of root diameter of Pinus tabuliformis on friction characteristics for root-soil interface[J]. Journal of Beijing Forestry University, 2014, 36(3):90.
[12]
刘亚斌, 余冬梅, 胡夏嵩, 等. 黄土区灌木柠条锦鸡儿根-土间摩擦力学机制试验研究[J]. 农业工程学报, 2017,33(10):198. LIU Yabin, YU Dongmei, HU Xiasong, et al. Experimental study on root-soil friction mechanical of Caragana korshinskii Kom. mechanism in loess area[J]. Transactions of the CSAE, 2017, 33(10):198.
[13]
田佳, 曹兵, 及金楠, 等. 花棒沙柳根与土及土与土界面直剪摩擦试验与数值模拟[J]. 农业工程学报, 2015, 31(13):149. TIAN Jia, CAO Bing, JI Jinnan, et al. Direct shear friction test and numerical simulation of soil-soil and root-soil interface of Hedysarum scoparium and Salix psammophila[J]. Transactions of the CSAE, 2015, 31(13):149.
[14]
黄同丽, 唐丽霞, 张乔艳, 等. 喀斯特区3种灌木根系构型及其生态适应策略[J]. 中国水土保持科学, 2019, 17(1):89. HUANG Tongli, TANG Lixia, ZHANG Qiaoyan, et al. Root architecture and ecological adaptation strategy of three shrubs in karst area[J]. Science of Soil and Water Conservation, 2019,17(1):89.
[15]
张乔艳, 唐丽霞, 潘露, 等. 石漠化区多花木蓝和双荚决明根土复合体抗剪特性研究[J]. 西南林业大学学报(自然科学), 2019, 39(4):18. ZHANG Qiaoyan, TANG Lixia, PAN Lu, et al. Shearing characteristics of root-soil compisite of Indigofera amblyanthy and Cassia bicapsularis in rocky desertification area[J]. Journal of Southwest Forestry University(Natural Science), 2019, 39(4):18.
[16]
解明曙. 林木根系固坡土力学机制研究[J]. 水土保持学报, 1990,4(3):7. JIE Mingshu. Study on mechanical mechanism of slope soil stabilization by tree roots[J]. Journal of Soil and Water Conservation, 1990,4(3):7.
[17]
JI Xiaodong, CONG Xu, DAI Xianqing, et al. Studying the mechanical properties of the soil-root interface using the pullout test method[J]. Journal of Mountain Ence, 2018, 15(4):882.
[18]
刘亚斌, 余冬梅, 胡夏嵩, 等. 寒旱环境黄土区灌木植物根系拉拔试验及其根系表面微观结构特征研究[J]. 岩石力学与工程学报, 2018, 37(S1):3701. LIU Yabin, YU Dongmei, HU Xiasong, et al. Research on pull-out test and surface microstructure features of shrubs roots in loess area of cold and arid environment[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(S1):3701.
[19]
刘亚斌, 胡夏嵩, 余冬梅. 西宁盆地黄土区2种灌木植物根-土界面微观结构特征及摩擦特性试验[J]. 岩石力学与工程学报, 2018, 37(5):1270. LIU Yabin, HU Xiasong, YU Dongmei. Microstructural features and friction characteristics of the interface of shrub roots and soil in loess area of Xining Basin[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(5):1270.
[20]
曹云生, 陈丽华, 刘小光, 等. 植物根土界面摩擦力的影响因素研究[J]. 摩擦学学报, 2014, 34(5):482. CAO Yunsheng, CHEN Lihua, LIU Xiaoguang, et al. The influence factors of plant root-soil interface friction[J]. Tribology, 2014, 34(5):482.
[21]
夏振尧, 刘琦, 许文年, 等. 多花木蓝根系与土体界面摩阻特征[J]. 水土保持学报, 2018, 32(1):128. XIA Zhenyao, LIU Qi, XU Wennian, et al. Characteristics of interface friction between Indigofera amblyanthy root system and soil[J]. Journal of Soil and Water Conservation, 2018, 32(1):128.
[22]
朱宏慧. 4类土根-土界面摩阻特性研究[D]. 呼和浩特:内蒙古农业大学, 2016, 69. ZHU Honghui. Friction characteristics of root-soil interface of 4 types of soil[D]. Huhhot:Inner Mongolia Agricultural University, 2016, 69.