植物根系直径和长度对于生态护坡作用的影响分析

Effects of plant root diameter and length on ecological slope protection

摘要

生态护坡中植物根系以加筋或锚固的方式加固土体，根系尺寸直接影响着植物的固土效率和边坡稳定性。以根径和根长为变量，通过数值计算方法，分析了不同根系尺寸下根-土复合体受拉拔-水平耦合荷载作用的位移响应。通过对比拉拔-水平荷载作用下根系、土体以及根-土复合体的位移特征曲线，分析了根径和根长对拉拔-水平荷载作用下根-土复合体变形的影响，阐明不同根系尺寸下根-土复合体位移演化规律。结果表明：拉拔-水平荷载作用下，根径对根-土复合体变形影响较弱，而根长越大，根-土复合体变形越小。当根长较短时，根-土复合体的位移增量主要集中在根壁上部两侧的土体。随着根长增加，根壁下部两侧土体的位移增量也随之增长。较长的根系能提供更大的锚固面积，因此能够更好地分散和承载荷载。短根情况下，土体变形主要发生在根的近端，而长根则能使变形模式更加均匀，影响到更远距离的土体，有利于土体的稳定性。

Abstract

In ecological slope protection, plant roots reinforce soil by reinforcing or anchoring, and root size directly affects the soil consolidation efficiency of plants and slope stability. With root diameter and root length as variables, the displacement response of root-soil complex under pull-out and horizontal coupling loads under different root sizes was analyzed by numerical method. By comparing the displacement characteristic curves of root, soil and root-soil complex under pull-out and horizontal loads, the influence of root diameter and root length on the deformation of the complex was analyzed, and the displacement evolution law of the complex under different root sizes was clarified. The result show that the influence of root diameter on the deformation of the root-soil complex is weak under pull-out horizontal load, but the larger the root length, the smaller the deformation of the root-soil complex. When the root length is short, the displacement increment of the root-soil complex is mainly concentrated on the soil on both sides of the root wall. With the increase of root length, the displacement increment of soil on both sides of root wall also increases. Longer roots provide a larger anchoring area and are therefore better able to disperse and carry loads. In the case of short roots, soil deformation mainly occurs at the near end of the root, while long roots can make the deformation pattern more uniform, affect the soil at a longer distance, and improve the stability of the whole system.

关键词

生态护坡 / 根系长度 / 根系直径 / 变形 / 根-土复合体

Key words

ecological slope protection / root length / root diameter / metamorphosis / root-soil complex

Author summay

曾 旻(1973—), 男, 高级工程师, 学士, 从事工程项目管理研究。E-mail: [e-mail]

基金资助

湖南省重点研发计划(2022SK2082)