关于剪切变形土体中单根受力—失效模式的试验研究和分析

《水土保持研究》[ISSN:1005-3409/CN:61-1272/P] 卷: 32 期数: 2025年05期页码: 246-255 栏目: 出版日期: 2025-10-10

Title:: Experimental study and analysis on force-failure mode of a single root in shear-deformed soil

文章编号:: 1005-3409（2025）05-0246-10

作者:: 闫相君¹，李亦璞²，王彦丹³，李通⁴，祁子寒¹，胡岂源⁵，王云琦¹; （1.北京林业大学水土保持学院重庆缙云山三峡库区森林生态系统国家定位观测研究站，北京100083；2.北京水保生态工程咨询有限公司，北京 100055；3.重庆市林业投资开发有限责任公司，重庆 401120；4.中国水利水电科学研究院，北京100083；5.重庆市水利电力建筑勘测设计研究院有限公司，重庆 400020）

Author(s):: Yan Xiangjun¹, Li Yipu², Wang Yandan³, Li Tong⁴, Qi Zihan¹, Hu Qiyuan⁵, Wang Yunqi¹; (1.Three-Gorges Reservoir Area(Chongqing) Forest Ecosystem Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China; 2.Beijing Soil and Water Conservation Ecological Engineering Consulting Co.,Ltd.,Beijing 100055,China; 3.Chongqing Forestry Investment Development Co.,Ltd., Chongqing 401120,China; 4.China Institute of Water Resources and Hydropower Research,Beijing 100083,China; 5.Chongqing Survey and Design Institute of Water Resources...)

关键词:

Keywords:

分类号:: S714.7

DOI:: 10.13869/j.cnki.rswc.2025.05.028

文献标志码:: A

摘要:: [目的] 通过室内试验与力学分析，旨在揭示剪切变形土体中单根受力状态下的失效机理及水分响应机制，阐明根系直径、土壤含水率等因素对轴向抗拉/抗拔与径向抗弯强度的影响规律，明确根系固土效应的主控力学路径。[方法] 室内设计了系列单根的轴向（根系抗拉、拔试验）和径向（三点弯曲试验）试验模拟受力情景，并分析了土壤含水率和根系含水率对根系抗拉、抗拔和抗弯试验中力学参数的影响。[结果]（1）根系的抗拉、抗拔和抗弯强度均呈现随根系直径增大而减小的趋势，其负数幂函数关系分别为Tr=（23.68±3.28）D（-0.38±0.10），Tp=（23.61±6.26）D（-0.55±0.25），Tb=4.945D-0.375；（2）土体饱和度增大过程中，根系自身含水率变化不大，对抗拉强度影响不显著（p=0.59），而根系抗拔强度则随饱和度的升高而显著衰减（p<0.01）；（3）根系轴向的抗拉、拔强度的相对大小存在一个随土壤含水率变化的临界直径阈值（0.35~3.96 mm）；（4）相对而言，根系对土体抗剪强度贡献主要来自于轴向受力，根系抗弯作用对土体抗剪强度的贡献非常有限。[结论] 植物根系力学特性与直径、土体水状态相关，根系轴向受力对土体抗剪强度有贡献，在固土中起重要作用且效果因条件而异。

Abstract:: [Objective] Through laboratory experiments and mechanical analysis, this study aims to reveal the failure mechanism and moisture response mechanism of a single root under force in shear-deformed soil, clarify the influence patterns of factors such as root diameter and soil moisture content on axial tensile and pull-out strength as well as radial bending strength, and identify the dominant mechanical pathways of the soil reinforcement effect of roots. [Methods] A series of laboratory experiments on a single root was conducted, including axial tests(tensile and pull-out strength tests of roots) and radial tests(three-point bending tests), to simulate different mechanical force scenarios. Moreover, the effects of both soil moisture content and root moisture content on mechanical parameters were analyzed in root tensile, pull-out, and bending strength tests. [Results](1) The tensile, pull-out, and bending strengths of roots all exhibited a decreasing trend with increasing root diameter, following negative power function relationships: Tr=(23.68±3.28)D(-0.38±0.10), Tp=(23.61±6.26)D(-0.55±0.25), Tb=4.945 D-0.375; (2) As soil saturation increased, root moisture content remained relatively stable and showed no significant impact on tensile strength(p=0.59). In contrast, the pull-out strength of roots significantly decreased with rising saturation levels(p<0.01); (3) A critical diameter threshold(0.35~3.96 mm) was observed for the relative magnitude of the axial tensile and pull-out strength of roots, which varied with soil moisture content; (4) In comparison, the contribution of roots to soil shear strength mainly stemmed from the axial force, while the effect of root bending strength remained negligible. [Conclusion] The mechanical properties of plant roots correlate with root diameter and soil moisture conditions. Axial force of roots contributes to soil shear strength, playing an important yet variable role in soil reinforcement depending on environmental factors.

参考文献/References:

相似文献/References:

备注/Memo

更新日期/Last Update: 2025-10-10