Reinforcement Effect of Herb Root System on Soil

doi:10.11988/ckyyb.20231043

Abstract

Abstract:

To investigate root-soil interaction and quantify the enhancement of soil shear strength by herb roots, an improved root-soil reinforcement model based on Wu and Waldron’s model was proposed by integrating three key factors: root distribution shear direction, anchorage length, and effective root number. The enhanced model was employed to examine the impact of the initial angle between the root and the shear surface, as well as root diameter, on soil reinforcement capacity. Results indicate that the improved model accurately fits the experimental data. Specifically, with the increase of the angle between root and shear plane, the reinforcement contribution of inversely oblique roots increases first and then decreases, while that of forward oblique roots increases first from zero and then decreases. Furthermore, with the increase of root diameter, the contribution of roots with varying distribution angles to soil reinforcement increases, roughly exhibiting a proportional relationship.

Key words: herbs, ecological slope protection, root-soil composite, reinforcement effect, soil reinforcement model

WANG Hai-tao, ZHANG Yu, LIU Lin-lin, CUI Ming-hua, SHEN Xiang-jun. Reinforcement Effect of Herb Root System on Soil[J]. Journal of Changjiang River Scientific Research Institute, 2025, 42(2): 100-106.

Figures/Tables 8

Fig.1 Root distribution and shear direction

Fig.2 Improved W & W’s model

Fig.3 Curves of test results and model calculation results

Table 1 Statistical results of ryegrass roots in samples

直径/mm	根数	与水平面夹角/(°)	直径/mm	根数	与水平面夹角/(°)
0.15~0.20	1	顺35	0.60~0.65	4	顺49、顺66、 90、逆44
0.20~0.25	1	逆46	0.65~0.70	1	逆67
0.25~0.30	1	顺58	0.70~0.75	2	顺82、逆59
0.30~0.35	1	顺84	0.75~0.80	1	逆58
0.35~0.40	2	顺32、逆53	0.80~0.85	1	顺76
0.40~0.45	2	顺64、逆71	0.85~0.90	1	逆73
0.45~0.50	2	顺52、顺65	0.90~0.95	1	90
0.50~0.55	2	顺48、顺56	0.95~0.10	1	逆78
0.55~0.60	2	顺74、逆53

Fig.4 Contribution of the initial angle of a single root to soil reinforcement (d=0.6 mm)

Fig.5 Relationship between tensile stress and shear displacement of a single root (d=0.6 mm)

Fig.6 Contribution of roots diameter to soil reinforcement

Fig.7 Relationship between root tensile stress and shear displacement

[1]	LIU Xiang-feng, ZHANG Qiang, HAO Guo-liang, WANG Yi-teng, SUN Ying-cong, WANG Lai-gui. 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.
[2]	CHENG Ping, LI Peng-cheng, ZHONG Cai-yin, HE Bo, WU Li-zhou. Mechanical Properties and Nonlinear Failure Criteria of Root-Soil Composite Dependent on Root Content [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(12): 110-117.
[3]	ZHANG Xiao-rong, MA Yan-xia, ZHANG Wu-yu. Influence Factors of Root-Soil Composite Slope Stability during Spring Thawing [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(11): 154-159.
[4]	FANG Lin, SUN Hong-xia, YANG Chun-jing, CHEN Cheng. Ecological Slope Protection Technology for Irrigation Canal Diverted from Yellow River [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(11): 51-55.
[5]	LIAO Tian-ting, JIANG Guan-lu, ZHANG Chong-lei, SHAN Yuan-chun, YE Xiong-wei. Numerical Analysis of Slope Protection Effect of Root System of Different Plants Considering Hydrological Effect [J]. Journal of Changjiang River Scientific Research Institute, 2022, 39(9): 102-108.
[6]	LIU Xiang-feng, HAO Guo-liang, YU Bing. Effect of Herb Plant Root System on the Reinforcement of Opencast Mine Dump [J]. Journal of Changjiang River Scientific Research Institute, 2022, 39(5): 83-88.
[7]	HU Qi-zhi, ZHOU Yong, MA Qiang, TAO Gao-liang. Experimental Study on Mechanical Properties of Composite Reinforced Soil with Root System and Grid [J]. Journal of Changjiang River Scientific Research Institute, 2022, 39(10): 109-115.
[8]	WU Song-hua. Field Test Study on Different Forms of Electroosmosis Reinforcementof Dredger-fill Silt [J]. Journal of Changjiang River Scientific Research Institute, 2020, 37(5): 108-112.
[9]	MA Qiang, LI Zhi, XIAO Heng-lin, WAN Juan. A Simplified Calculation Method for Shear Strength of Tap Root-Soil Composite [J]. Journal of Changjiang River Scientific Research Institute, 2020, 37(2): 112-118.
[10]	ZHANG Qiao-yan, TANG Li-xia, PAN Lu, HUANG Tong-li, CHEN Long. Mechanical Properties of Shrubs and Applicability of Model WU in Karst Area [J]. Journal of Changjiang River Scientific Research Institute, 2020, 37(12): 53-58.
[11]	WANG Shao-wei, ZHENG Chun-feng, SU Huai-zhi, FU Qi-min. A Cloud-model-based Approach for Comprehensive Evaluation of Reinforcement Effect of Dangerous Sluices [J]. Journal of Changjiang River Scientific Research Institute, 2019, 36(8): 61-66,80.
[12]	MA Chi, ZHU Ya-lin, PENG Xue-feng. Stability Analysis of Geogrid Reinforced High Earth-rockfill Dam under Seismic Action [J]. Journal of Changjiang River Scientific Research Institute, 2019, 36(11): 125-131.
[13]	LIU Xing-zong, TANG Chun-an, SUN Run. Reinforcement Mechanism and Effectiveness of Anti-shear Galleries in the Right Bank of Dagangshan Hydropower Station in the Process of Reservoir Impoundment [J]. Journal of Changjiang River Scientific Research Institute, 2019, 36(11): 104-109.
[14]	CHEN Yuan, ZHANG Lin, YANG Bao-quan, YANG Jin-wang, LI Si-ying. Stability of the Left Bank High Slope in Strong Unloading Area of Baihetan Hydropower Station [J]. Journal of Changjiang River Scientific Research Institute, 2018, 35(3): 144-150.
[15]	YANG Qi-lin,LI Bai. Growth Distribution of Bamboo Root System in LandslideArea and Its Slope Protection Effect [J]. Journal of Changjiang River Scientific Research Institute, 2017, 34(10): 45-49.