香根草根系在公路边坡土体中的分布特征  

Distribution Characteristics of Vetiver's Roots in Highway Slope

作　　者：李珍玉[1] 王丽锋 肖宏彬[1] 王皓磊[1] 杨慧[1] LI Zhenyu WANG Lifeng XIAO Hongbin WANG Haolei YANG Hui(College of Civil Engineering and Mechanics, Central South University of Forestry and Technology, Changsha 410004, China CCCC Fourth Highway Engineering CO. , Ltd： , Beijing 100022, China)

机构地区：[1]中南林业科技大学土木工程与力学学院,湖南长沙410004 [2]中交第四公路工程局有限公司,北京100022

出　　处：《应用基础与工程科学学报》2017年第1期102-112,共11页Journal of Basic Science and Engineering

基　　金：工程流变学湖南省重点实验室开放课题基金项目(14HNKLER02);国家自然科学基金项目(51608545);湖南省外国专家局资助项目(湘财教指[2012]26号)

摘　　要：模拟实际公路边坡坡度和土质条件,制作模型试验箱,并种植了根系发达的生态护坡植物——香根草.通过全断面开挖法,研究了在模型箱中生长了两年的香根草根系在边坡土体中的分布特征.结果表明:在贫瘠土壤条件下,两年生香根草的根系垂直向下生长,最大根长达1m多,其根系生物量沿土层剖面深度呈二项式函数关系减少;根系直径约为0.8~1.4mm,且根径>1mm的根系居多,最粗者可达2.2mm;香根草根系的分布范围随土层深度呈先增大后减小的趋势,其分布规律可以用Gauss曲线来描述;沿土层剖面自上而下,根系密度分布规律服从Logistic曲线关系;香根草的大部分根系偏向坡脚方向生长,坡脚方向生长的根系粗长且密集,而坡顶方向生长的根系则细短且稀疏.以上对根系形态分布规律的研究可为进一步分析植物根系与土体间的相互作用机理、防治边坡水土流失、浅层滑坡等地质灾害提供理论基础.An experimental study was carried out to investigate the distribution characteristics of vetiver roots in highway soil slope. Model boxes with simulated side slope and soil conditions of a practical project were constructed; and vetiver known for its stabilizing role on soil slope were planted in these model boxes. By using full face excavation method, the distribution characteristics of two-year-old vetiver roots in soil slope and the stabilizing effects of vetiver roots system on highway slope were focused on in this study. The test results indicated that, under poor soil conditions, vetiver roots grow vertically downward, its maximum length reaches more than l m, and along the depth of soil profile, the root biomass reduces according to the binomial function. The diameters of roots vary mainly from 0. 8 to 1.4mm, and diameters greater than lmm is the majority,some even up to 2. 2mm. The distribution range of vetiver root system along the soil depth tends to go up at the beginning followed by a decrease, and can be described by Gauss curve. On the other hand, along the soil depths the density distributions of roots are in accordance with Logistic curve. Most of vetiver roots tend to grow along the direction of slope toe ; roots grown along the slope toe are thicker, longer and denser than those grown along the slope top. This study provides a theoretical basis for the further analysis of the interaction mechanism between vetiver roots and soil, and it also has an important significance for the prevention and control of geological disasters, such as ecological slope erosion, shallow landslides etc.

关 键 词：生态护坡 香根草根系 根-土相互作用 根系形态 根系密度 

分 类 号：S774[农业科学—森林工程]