Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>

Rainfall-induced weakening of the root–loess interface’s shear strength is a key factor in slope instability, yet research on its shear characteristics remains limited. This study classifies <i>Robinia pseudoacacia</i> roots into three types (0–2 mm, 2–5 mm, and 5–10 mm) based on field s...

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Main Authors: Qi Gu, Bo Hong, Qiangbing Huang, Xiaosen Kang, Dengfei Zhang, Xiaopeng Guo, Gang Liu, Tao Xiao
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Agronomy
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Online Access:https://www.mdpi.com/2073-4395/15/4/847
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author Qi Gu
Bo Hong
Qiangbing Huang
Xiaosen Kang
Dengfei Zhang
Xiaopeng Guo
Gang Liu
Tao Xiao
author_facet Qi Gu
Bo Hong
Qiangbing Huang
Xiaosen Kang
Dengfei Zhang
Xiaopeng Guo
Gang Liu
Tao Xiao
author_sort Qi Gu
collection DOAJ
description Rainfall-induced weakening of the root–loess interface’s shear strength is a key factor in slope instability, yet research on its shear characteristics remains limited. This study classifies <i>Robinia pseudoacacia</i> roots into three types (0–2 mm, 2–5 mm, and 5–10 mm) based on field surveys and 3D laser scanning. Large-scale, direct shear tests and three-dimensional failure surface reconstruction were conducted using a self-developed apparatus to examine the effects of water content (5%, 12%, and 19%), root type, and root content ratio (2.11%, 1.17%, and 0.23%) on shear strength and failure morphology. Results indicate that increasing water content reduces shear resistance, while root type and content ratio enhance cohesion. Shear resistance follows an order: Type II > Type III > Type I, influenced by root curvature, and increases with root content. A novel correlation is identified between shear strength and the fractal dimension of the failure surface. This study proposes a self-locking and interlocking mechanism based on micromechanical force chains between roots and soil particles, offering new insights into root–loess interface mechanics and a theoretical basis for evaluating vegetative root reinforcement under rainfall conditions.
format Article
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institution DOAJ
issn 2073-4395
language English
publishDate 2025-03-01
publisher MDPI AG
record_format Article
series Agronomy
spelling doaj-art-0a546196b3be4ff69836fb227dc2895e2025-08-20T03:14:24ZengMDPI AGAgronomy2073-43952025-03-0115484710.3390/agronomy15040847Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>Qi Gu0Bo Hong1Qiangbing Huang2Xiaosen Kang3Dengfei Zhang4Xiaopeng Guo5Gang Liu6Tao Xiao7Key Laboratory for Geo-Hazard in Loess Area MNR, Xi’an Center of China Geological Survey, Xi’an 710119, ChinaKey Laboratory for Geo-Hazard in Loess Area MNR, Xi’an Center of China Geological Survey, Xi’an 710119, ChinaSchool of Geological Engineering and Geomatics, Chang’an University, Xi’an 710064, ChinaSchool of Geological Engineering and Geomatics, Chang’an University, Xi’an 710064, ChinaSchool of Geological Engineering and Geomatics, Chang’an University, Xi’an 710064, ChinaKey Laboratory for Geo-Hazard in Loess Area MNR, Xi’an Center of China Geological Survey, Xi’an 710119, ChinaKey Laboratory for Geo-Hazard in Loess Area MNR, Xi’an Center of China Geological Survey, Xi’an 710119, ChinaDepartment of Geology, Northwest University, Xi’an 710069, ChinaRainfall-induced weakening of the root–loess interface’s shear strength is a key factor in slope instability, yet research on its shear characteristics remains limited. This study classifies <i>Robinia pseudoacacia</i> roots into three types (0–2 mm, 2–5 mm, and 5–10 mm) based on field surveys and 3D laser scanning. Large-scale, direct shear tests and three-dimensional failure surface reconstruction were conducted using a self-developed apparatus to examine the effects of water content (5%, 12%, and 19%), root type, and root content ratio (2.11%, 1.17%, and 0.23%) on shear strength and failure morphology. Results indicate that increasing water content reduces shear resistance, while root type and content ratio enhance cohesion. Shear resistance follows an order: Type II > Type III > Type I, influenced by root curvature, and increases with root content. A novel correlation is identified between shear strength and the fractal dimension of the failure surface. This study proposes a self-locking and interlocking mechanism based on micromechanical force chains between roots and soil particles, offering new insights into root–loess interface mechanics and a theoretical basis for evaluating vegetative root reinforcement under rainfall conditions.https://www.mdpi.com/2073-4395/15/4/847ecological environmentloess plateauroot–loess interface<i>Robinia pseudacacia root</i>single shear test
spellingShingle Qi Gu
Bo Hong
Qiangbing Huang
Xiaosen Kang
Dengfei Zhang
Xiaopeng Guo
Gang Liu
Tao Xiao
Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>
Agronomy
ecological environment
loess plateau
root–loess interface
<i>Robinia pseudacacia root</i>
single shear test
title Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>
title_full Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>
title_fullStr Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>
title_full_unstemmed Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>
title_short Macro–Microscale Research on the Single Shear Characteristics of the Root–Loess Interface in <i>Robinia pseudoacacia</i>
title_sort macro microscale research on the single shear characteristics of the root loess interface in i robinia pseudoacacia i
topic ecological environment
loess plateau
root–loess interface
<i>Robinia pseudacacia root</i>
single shear test
url https://www.mdpi.com/2073-4395/15/4/847
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