紫花苜蓿根面积比对边坡稳定性的影响

doi:10.16178/j.issn.0528-9017.20240384

摘要/Abstract

摘要：

近年来,护坡工程备受关注,以紫花苜蓿等草本植物为主的生态护坡逐渐成为护坡工程的首选。本研究搜集了紫花苜蓿根-土复合体直接剪切的试验数据,采用相关分析方法,初步探讨了根面积比(RAR)与土体黏聚力增幅(Δc/c₀)、内摩擦角增幅(Δφ/φ₀)的相关性;运用有限元软件PLAXIS 3D模拟边坡,研究了不同RAR下边坡安全系数与总位移的变化规律。结果表明,种植紫花苜蓿能够提高坡体黏聚力,进而有效加固坡体,提升边坡稳定性,且存在最优根面积比0.3%,此时根系对边坡土体的加固效果最优。该研究可为浅层边坡的生态固土提供参考。

关键词: 紫花苜蓿, 根面积比, 黏聚力, PLAXIS 3D, 数值分析

Abstract:

Slope protection projects have attracted much attention in recent years. Ecological slope protection based on herbaceous plants such as Medicago sativa L. has gradually become the first choice for slope protection projects. Based on the collected direct shear test data of Medicago sativa L. roots, the correlation between root area ratio (RAR) and the increase of soil cohesion (Δc/c₀) and the increase of internal friction angle (Δφ/φ₀) was preliminarily discussed by correlation analysis method. The finite element software PLAXIS 3D was used to simulate the slope, and the variation law of slope safety factor and total displacement under different RAR was studied. The results showed that Medicago sativa L. can increase the cohesive force of the slope and thus effectively reinforce the slope and improve the stability of the slope, and there was an optimal root area ratio of 0.3%. At this time, the root system had the best reinforcement effect on the slope soil. This study can provide reference for ecological soil reinforcement of shallow slope.

Key words: Medicago sativa L., root area ratio, cohesive force, PLAXIS 3D, numerical analysis

中图分类号:

S541.9

刘晨, 吕羿, 高新南. 紫花苜蓿根面积比对边坡稳定性的影响[J]. 浙江农业科学, 2026, 67(1): 178-183.

LIU Chen, LYU Yi, GAO Xinnan. Effect of the influence of Medicago sativa L. root area ratio on slope stability[J]. Journal of Zhejiang Agricultural Sciences, 2026, 67(1): 178-183.

图/表 5

图1 RAR与黏聚力增幅(a)、内摩擦角增幅(b)的拟合关系

Fig.1 Fitting relationship between RAR and the increase of soil cohesion (a) and internal friction angle (b)

图2 边坡几何模型

Fig.2 Slope geometric model

图3 不同根面积比下的边坡安全系数

Fig.3 Slope safety factors under different root area ratios

图4 不同根面积比下边坡偏应变增量的分布云图

Fig.4 Distribution cloud diagram of slope deviatoric strain increment under different RAR

图5 根面积比与边坡总位移的关系曲线

Fig.5 The relationship curve between the root area ratio and the total displacement of the slope

参考文献 18

[1]	程洪, 张新全. 草本植物根系网固土原理的力学试验探究[J]. 水土保持通报, 2002, 22(5): 20-23.
	CHENG H, ZHANG X Q. An experimental study on herb plant root system for strength principle of soil-fixation[J]. Bulletin of Soil and Water Conservation, 2002, 22(5): 20-23.
[2]	WALDRON L J. The shear resistance of root-permeated homogeneous and stratified soil[J]. Soil Science Society of America Journal, 1977, 41(5): 843-849.
[3]	WU T H, MCKINNELL W P, SWANSTON D N. Strength of tree roots and landslides on prince of Wales Island, Alaska[J]. Canadian Geotechnical Journal, 1979, 16(1): 19-33.
[4]	杨亚川, 莫永京, 王芝芳, 等. 土壤-草本植被根系复合体抗水蚀强度与抗剪强度的试验研究[J]. 中国农业大学学报, 1996, 1(2): 31-38.
	YANG Y C, MO Y J, WANG Z F, et al. Experimental study on anti-water erosion and shear strength of soil-root composite[J]. Journal of China Agricultural University, 1996, 1(2): 31-38.
[5]	孙高峰, 王金霞, 杨旸, 等. 草本植物根系提高土体无侧限抗压强度及Wu & Waldron模型预测[J]. 江苏农业科学, 2019, 47(14): 263-268.
	SUN G F, WANG J X, YANG Y, et al. Herbaceous roots improve unconfined compressive strength of soil mass and prediction of Wu & Waldron model[J]. Jiangsu Agricultural Sciences, 2019, 47(14): 263-268.
[6]	祁兆鑫, 余冬梅, 刘亚斌, 等. 寒旱环境盐生植物根-土复合体抗剪强度影响因素试验研究[J]. 工程地质学报, 2017, 25(6): 1438-1448.
	QI Z X, YU D M, LIU Y B, et al. Experimental research on factors affecting shear strength of halophyte root-soil composite systems in cold and arid environments[J]. Journal of Engineering Geology, 2017, 25(6): 1438-1448.
[7]	刘向峰, 张强, 郝国亮, 等. 草本植物根系类型和分布对根土复合体无侧限抗压强度的影响[J]. 长江科学院院报, 2023, 40(9): 106-111.
	LIU X F, ZHANG Q, HAO G L, et al. Effects of herb root type and distribution on unconfined compressive strength of root-soil composites[J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(9): 106-111.
[8]	孙铁军, 聂明鹤, 滕文军, 等. 不同生态修复草种对土壤水分蒸散的影响[J]. 北方园艺, 2024(3): 71-78.
	SUN T J, NIE M H, TENG W J, et al. Effects of different grasses for ecological restoration on soil evapotranspiration[J]. Northern Horticulture, 2024(3): 71-78.
[9]	毛正君, 张瑾鸽, 毕银丽, 等. 紫花苜蓿对黄土边坡浅层破坏防护时间效应的数值分析[J]. 农业工程学报, 2022, 38(15): 72-83.
	MAO Z J, ZHANG J G, BI Y L, et al. Numerical analysis of protection time effect on planting alfalfa in loess slope with shallow failure[J]. Transactions of the Chinese Society of Agricultural Engineering, 2022, 38(15): 72-83.
[10]	崔明华. 大连地区生态护坡草本植物根系固土机理和护坡稳定性分析[D]. 大连: 大连交通大学, 2023: 38-42.
	CUI M H. Analysis of soil consolidation mechanism and slope stability of herbaceous plant roots in ecological slope protection in Dalian area[D]. Dalian: Dalian Jiaotong University, 2023: 38-42.
[11]	海龙, 谭世林, 徐博. 紫花苜蓿和通奶草根土复合体的力学特性[J]. 水土保持通报, 2023, 43(6): 57-64.
	HAI L, TAN S L, XU B. Mechanical properties of Medicago sativa and Euphorbia hypericifolia root-soil complex[J]. Bulletin of Soil and Water Conservation, 2023, 43(6): 57-64.
[12]	王贵荣, 王凯, 袁林, 等. 紫花苜蓿根系-砂土复合体力学特性[J]. 西安科技大学学报, 2023, 43(1): 99-108.
	WANG G R, WANG K, YUAN L, et al. Mechanical properties of alfalfa root-soil composite[J]. Journal of Xi'an University of Science and Technology, 2023, 43(1): 99-108.
[13]	包含, 敖新林, 高月升, 等. 黄土边坡典型护坡植被的根系加固力学效应演化分析[J]. 中国公路学报, 2024, 37(6): 98-110.
	BAO H, AO X L, GAO Y S, et al. Evolution analysis of root reinforcement mechanical effect of typical plant protection on loess slope[J]. China Journal of Highway and Transport, 2024, 37(6): 98-110.
[14]	张鲁渝, 郑颖人, 赵尚毅, 等. 有限元强度折减系数法计算土坡稳定安全系数的精度研究[J]. 水利学报, 2003, 34(1): 21-27.
	ZHANG L Y, ZHENG Y R, ZHAO S Y, et al. The feasibility study of strength-reduction method with FEM for calculating safety factors of soil slope stability[J]. Journal of Hydraulic Engineering, 2003, 34(1): 21-27.
[15]	赵秋. 北方低产土壤实用绿肥作物栽培与利用[M]. 天津: 天津科技翻译出版公司, 2010: 13-15.
[16]	钟佩文, 张慧莉, 田堪良, 等. 持续降雨入渗对黄土边坡稳定性的影响[J]. 人民黄河, 2018, 40(1): 76-81.
	ZHONG P W, ZHANG H L, TIAN K L, et al. Study on the influence of continuous rainfall infiltration on the loess slope stability[J]. Yellow River, 2018, 40(1): 76-81.
[17]	ZIENKIEWICZ O C, HUMPHESON C, LEWIS R W. Associated and non-associated visco-plasticity and plasticity in soil mechanics[J]. GÉotechnique, 1975, 25(4): 671-689.
[18]	李宗坤, 李艳, 赵凤遥. 土体物理力学指标对黏土边坡变形的影响[J]. 人民黄河, 2008, 30(12): 109-110.
	LI Z K, LI Y, ZHAO F Y. Influence of physical and mechanical indexes of soil on deformation of clay slope[J]. Yellow River, 2008, 30(12): 109-110.