拉拔-水平荷载作用下三维根系对土体变形规律的影响

Influence of three-dimensional root system on soil deformation under pull-out and horizontal loads

摘要

植物根系在三维空间中的生长和交织能够显著增强土体的力学性能，采用数值模拟方法，分别从二维与三维计算差异角度出发，构建复杂根系-土体复合体二维和三维分析模型，研究逐级拉拔-水平耦合荷载作用下，土体和根系位移的变化规律，揭示复杂根系-土体复合体相互作用机制。发现：复杂根系比单一根系能够更有效地限制土体变形。由于根-土界面面积增加，三维复杂根系固土性能优于二维分布的根系。与二维根系的比较，三维复杂根系下位移测线的急剧变化出现在更高的荷载值上，三维根系与二维根系相比计算得到的拉拔-水平耦合荷载更大。三维根系的位移等值线随荷载增加而趋向于三角形，这是因为三维根系结构提供了额外的土体锚固点，从而改变了位移模式。

Abstract

The growth and interweaving of plant roots in three-dimensional space can significantly enhance the mechanical properties of soil. A numerical simulation method is used to construct two-dimensional and three-dimensional analysis models of complex root-soil complex from the perspective of two-dimensional and three-dimensional calculation differences, respectively, to study the change law of soil and root displacement under stepwise pull-out and horizontal coupling loads. To reveal the interaction mechanism of complex root-soil complex. It is found that complex root system can limit soil deformation more effectively than single root system. Due to the increase of root-soil interface area, the soil consolidation performance of three-dimensional complex root system is better than that of two-dimensional simple distributed root system. Compared with 2D roots, the sharp change of displacement line under 3D complex roots appears at higher load values, and the calculated pull-horizontal coupling load of 3D roots is larger than that of 2D roots. The displacement contour of the three-dimensional root system tends to be triangular with the increase of load, because the three-dimensional root system provides additional anchorage points, which changes the displacement mode.

关键词

生态护坡 / 复杂根系 / 数值模拟 / 变形 / 三维计算

Key words

ecological slope protection / complex root system / numerical simulation / metamorphosis / three-dimensional computation

Author summay

杜文辉(1975—), 男, 高级工程师, 学士, 从事铁道工程施工与设计方面的科研与生产。E-mail: [e-mail]

基金资助

湖南省重点研发计划(2022SK2082)

国家自然科学基金(42277175)