文献类型：期刊文献

中文题名：根-土复合体的胀缩变形及干湿循环后的力学特性研究

英文题名：Study on the swell-shrinking deformation and mechanical properties of the root-soil composites after dry-wet cycles

作者：陈筠 陈泰徐 王爽 王连锐 邬忠虎

第一作者：陈筠

机构：[1]贵州理工学院继续教育学院,贵州贵阳550003;[2]贵州大学资源与环境工程学院,贵州贵阳550025;[3]中国电建集团贵阳勘测设计研究院,贵州贵阳550081;[4]贵州大学喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025;[5]贵州大学土木工程学院,贵州贵阳550025

第一机构：贵州理工学院继续教育学院

年份：2023

卷号：54

期号：5

起止页码：136-146

中文期刊名：水利水电技术(中英文)

外文期刊名：Water Resources and Hydropower Engineering

收录：CSTPCD;;北大核心:【北大核心2020】；

基金：国家自然科学基金项目(52104080);贵州省地质灾害监测预警与决策支持平台建设(Z113278);贵州省科学技术基金项目(黔科合基础[2019]1142)。

语种：中文

中文关键词：红黏土;根-土复合体;干湿循环;膨胀变形;抗剪强度;边坡;含水率;生态防护

外文关键词：red clay soil;root-soil system;drying-wetting cycle;swelling-shrinking deformation;shear strength;slope;water content;ecological protection

摘要：【目的】边坡生态防护具有自然生态修复和固土作用,经济效益斐然。为了研究干湿循环作用下植物根系对红黏土的加固机理和生态防护在红黏土分布区的适用性。【方法】以贵州省贵阳市红黏土为研究对象,采用膨胀试验和收缩变形试验,探究根-土复合体在不同初始含水率下的胀缩性能,并采用固结快剪试验,测定干湿循环作用下不同循环幅度和不同初始含水率时根-土复合体的抗剪强度参数,从而分析干湿循环作用下根系的掺入对红黏土强度变化的影响。【结果】研究结果显示:(1)所测红黏土的自由膨胀率为58.0%,属弱膨胀土。膨胀率和线缩率分别随初始含水率的增加而减小和增加,根系的掺入能够有效抑制土体的胀缩变形,抑制强弱与根系含量和土体含水率有关。(2)当循环幅度分别为10%、20%和30%,且初始含水率和根系掺量一定时,根-土复合体的抗剪强度较5次循环前呈现先增大后减小的趋势。(3)当初始含水率分别为40%、50%和60%,且循环幅度和根系掺量一定时,根-土复合体的抗剪强度较5次循环前总体上随初始含水率的增加而减小。【结论】根系的掺入能够有效抑制干湿循环作用下红黏土抗剪强度的衰减。研究成果将进一步加深对红黏土力学特性和边坡生态防护的认识。
[Objective]Slope ecological protection has natural ecological restoration and soil consolidation effects,with remarkable economic benefits.In order to study the reinforcement mechanism of plant roots on red clay under drying-wetting cycle and the applicability of ecological protection in red clay distribution areas.[Methods]Taking the red clay in Guiyang City,Guizhou Province as the research object,the swelling-shrinking deformation tests were conducted to explore the swelling and shrinking properties of root-soil system under different initial moisture contents.The consolidation fast shear test was also used to determine the shear strength parameters of the root-soil system under different cyclic amplitudes and initial moisture contents under drying-wetting cycles,in order to analyze the impact of root system incorporation on the strength changes of red clay under drying-wetting cycles.[Results]The results show that:(1)The measured free swelling ratio of red clay is 58.0%,which belongs to weak expansive soil.The swelling ratio and linear shrinkage rate decrease and increase with the increase of initial moisture content,respectively.The addition of roots can effectively suppress the swelling and shrinking deformation of soil,and the strength of inhibition is related to the root content and soil moisture content.(2)When the cyclic amplitude is 10%,20%,and 30% respectively,and the initial moisture content and root content are constant,the shear strength of the root-soil system shows a trend of first increasing and then decreasing compared to before 5 drying-wetting cycles.(3)When the initial moisture content is 40%,50%,and 60%,and the cyclic amplitude and root content are constant,the shear strength of the root-soil system decreases overall with the increase of the initial moisture content compared to before 5 drying-wetting cycles.[Conclusion]The results indicate that the addition of root system can effectively suppress the attenuation of shear strength of red clay under drying-wetting cycles,and the research results will further deepen the understanding of the mechanical properties of red clay and slope ecological protection.