含水率对根-土石复合体抗剪强度影响的试验研究——以垂丝海棠为例  

Experimental Study on the Influence of Water Content on the Shear Strength of Root-Soil-Rock Composite--A Case Study of Malus halliana

作　　者：陶首仲 周花玉 张卓超 樊东升 郑峰 刘含霞 周张路 刘建平 TAO Shouzhong;ZHOU Huayu;ZHANG Zhuochao;FAN Dongsheng;ZHENG Feng;LIU Hanxia;ZHOU Zhanglu;LIU Jianping(College of Water Conservancy and Hydropower Engineering,Sichuan Agricultural University,Yaan 625014,Sichuan,China;Central and Southern China Municipal Engineering Design and Research Institute Co.,Ltd.,Wuhan 430010,China)

机构地区：[1]四川农业大学水利水电学院,四川雅安625014 [2]中国市政工程中南设计研究总院有限公司,武汉430010

出　　处：《四川农业大学学报》2024年第3期613-619,共7页Journal of Sichuan Agricultural University

基　　金：国家自然科学基金(41907242);大学生创新训练计划项目(2221998240、2321998131)。

摘　　要：【目的】探究含水率对根-土石复合体抗剪强度的影响规律。【方法】以四川农业大学雅安校区老板山典型固坡植物垂丝海棠为研究对象,固定剪切面含根量为0.2%、含石量为30%,设置5种含水率梯度(10%、15%、20%、25%、30%),分别在50、100、150和200 kPa的四级正应力下进行室内直接剪切试验,分析含水率对抗剪强度及其指标(黏聚力和内摩擦角)的影响规律。【结果】根-土石复合体的抗剪强度随正应力的增大而增高,符合莫尔-库伦强度准则,其抗剪强度随含水率的升高呈先下降后上升随之再下降的趋势,呈多峰曲线变化,在含水率为20%时取得最小值;含水率对根-土石复合体的黏聚力影响较大,在含水率为25%时取得临界峰值,但含水率对根-土石复合体的内摩擦角影响较小。【结论】含水率的变化主要影响根-土石复合体的黏聚力,从而影响根-土石复合体的峰值抗剪强度,而对内摩擦角的影响较小。研究结果可为植被加固土石混合体边坡提供一定的理论支撑。【Objective】The aim of this study is to investigate the effect of water content on the shear strength of root-soil-rock composite.【Method】This study was conducted on Malus halliana,a typical slope stabilization plant on the Laoban Mountain of Yaan campus,Sichuan Agricultural University.Five gradiants of water content(10%,15%,20%,25%,30%)were set on a fixed shear surface with root content of 0.2%and stone content of 30%.Direct shear tests were carried out with four different normal stresses of 50,100,150 and 200 kPa.The influence of water content on the shear strength and its in⁃dexes(cohesion and internal friction angle)were analyzed.【Result】The shear strength of the root-soil-rock composite increased with the rising of normal stress,suggesting adherence to the Mohr-Coulomb strength criterion.Additionally,the shear strength of the composite decreased first,then increased and followed by a decrease with the increase of water content,characterized by a multi-peak curve pattern with a minimum value observed at 20%water content.The cohesion of the root-soil-rock composite was affected by the water content significantly,and reaching a critical peak at 25%.In contrast,the internal friction angle of the root-soil-rock composite showed minimal variation with changing water content. 【Conclusion】 The change of water content primarily affects the cohesion of the root-soil-rock compos⁃ ite, and thus influence the peak shear strength while having minimal impact on the internal friction angle. The findings of this study could provide theoretical support for the reinforcement of soil-rock mixture slope through vegetation.

关 键 词：边坡工程 根-土石复合体 含水率 抗剪强度 垂丝海棠 

分 类 号：S157.2[农业科学—土壤学]