干旱区生态环境知识资源中心(Arid): 寒旱环境灌木植物根-土复合体强度模型试验研究

Arid

	寒旱环境灌木植物根-土复合体强度模型试验研究
其他题名	RESEARCH ON STRENGTH MODEL TEST OF SHRUB ROOT-SOIL COMPOSITE SYSTEM IN COLD AND ARID ENVIRONMENTS
	余芹芹 1; 胡夏嵩 1; 李国荣 1; 乔娜 1; 卢海静 1; 付江涛 2; 李华坦 1
来源期刊	岩石力学与工程学报
ISSN	1000-6915
出版年	2013
卷号	32 期号:5 页码:1020-1031
中文摘要	在自行设计、加工的原位剪切试验装置中分别种植灌木植物霸王和柠条锦鸡儿,通过对2种坡度的素土、霸王根-土复合体和柠条锦鸡儿根-土复合体进行原位剪切试验,测得素土和根-土复合体抗剪力、抗剪强度的动态变化,评价灌木植物护坡的时间效应,并采用室内直剪试验方法检验原位剪切试验结果的合理性。试验得出以下结论:(1)根-土复合体的抗剪力和抗剪强度均大于同种坡度的素土,即植物根系可显著提高边坡土体的抗剪能力,且霸王根-土复合体抗剪力和抗剪强度主要体现在剪切面处断裂根系的抗拉或抗剪作用、拔出根系的根-土摩擦力及滑移根系的锚固、摩擦作用,柠条锦鸡儿根-土复合体主要体现在根系的锚固和根-土摩擦作用,同时,素土和灌木根-土复合体的抗剪力和抗剪强度随着坡度的增加而减小;(2)素土的剪切力在3 s左右达到峰值,而根-土复合体的剪切力峰值时间为69.8~168.2 s;素土试样在剪切位移为1 mm内抗剪强度均达到峰值,而剪切位移为23.13~83.13 mm时霸王根-土复合体和柠条锦鸡儿根-土复合体抗剪强度达到峰值,即根-土复合体的剪切力峰值时间、抗剪强度峰值位移均较素土相对滞后,这反映了在剪切过程中根系的抗拉能力、根-土界面的摩擦作用逐步转化为根-土复合体的抗剪能力,从而延缓坡面变形破坏的时间;(3)为了验证原位剪切试验结果的准确性,对素土和灌木根-土复合体进行室内直剪试验,其抗剪强度值与原位剪切试验值接近,反映原位剪切试验及其结果的合理性。上述研究成果对于开展研究区西宁盆地及其周边地区坡面水土流失、浅层滑坡等地质灾害的防治,以及对青藏高原东北部黄土地区边坡生态工程建设、区域生态环境保护具有重要的理论指导价值和现实意义。
英文摘要	Zygophyllum xanthoxylon and Caragana korshinskii are shrubs planted separately in in-situ shear test devices designed and worked out by the researchers. The dynamic variation on the shear resistance,shear strength of the soil without roots and root-soil composite systems are observed from two degrees of slope via in-situ shear test on soil without roots,Zygophyllum xanthoxylon root-soil composite system and Caragana korshinskii root-soil composite system. At the same time,the time effect of slope protection for shrubs is evaluated;and the accuracy of the in-situ shear test is proved by indoor direct shear tests. The results show:(1) At the same degree of slope,the shear resistance and shear strength of root-soil composite system are larger than those of soil without roots,i.e. plant roots can significantly improve the shear capability of slope soil. The shear resistance and shear strength of Zygophyllum xanthoxylon root-soil composite system are reflected in tension or shear of broken roots,friction between soil and pulled-out roots,anchor and friction of slipped roots,while those of Caragana korshinskii root-soil composite system from the anchor of roots and friction between roots and soil. The shear resistance and shear strength of soil without roots and shrub root-soil composite systems decrease with the slope degree increase. (2) The shear resistance of soil without roots reaches its peak value after three seconds,while that of root-soil composite system reaches the peak values after 69.8 to 168.2 seconds. The shear strength of soil without roots reaches the peak value when the displacements are within one millimeter,while that of root-soil composite system reach the peak values when the displacements are from 23.13 to 83.13 millimeter,i.e. the peak time of shear resistance and peak displacement of shear strength for root-soil composite system appear later than those of soil without roots. Those findings reflect that the tensile capability of roots and the friction between roots and soil during the process of shearing gradually transform to be the shear ability which can delay the slope deformation and failure. (3) To prove the accuracy of in-situ shear test,indoor direct shear tests on soil without roots and shrub root-soil composite systems are conducted. The shear strength values of indoor direct shear tests approach the values of the in-situ shear test,showing that the method and the results of in-situ shear test are rational. Those achievements have theoretical and practical values in constructing ecological engineering,protecting ecological environment and preventing geological catastrophes,such as soil and water loss,shallow landslide in Xining basin and the loess slopes of northeast Qinghai-Tibet plateau.
中文关键词	土力学 ; 寒旱环境 ; 原位剪切试验 ; 根-土复合体 ; 抗剪强度 ; 模型试验
英文关键词	soil mechanics cold and arid environments in-situ shear test root-soil composite system shear strength model test
语种	中文
国家	中国
收录类别	CSCD
WOS类目	CONSTRUCTION BUILDING TECHNOLOGY
WOS研究方向	Construction & Building Technology
CSCD记录号	CSCD:4892346
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/230376
作者单位	1.青海大学地质工程系, 西宁, 青海 810016, 中国; 2.中国科学院青海盐湖研究所, 西宁, 青海 810008, 中国
推荐引用方式 GB/T 7714	余芹芹,胡夏嵩,李国荣,等. 寒旱环境灌木植物根-土复合体强度模型试验研究[J],2013,32(5):1020-1031.
APA	余芹芹.,胡夏嵩.,李国荣.,乔娜.,卢海静.,...&李华坦.(2013).寒旱环境灌木植物根-土复合体强度模型试验研究.岩石力学与工程学报,32(5),1020-1031.
MLA	余芹芹,et al."寒旱环境灌木植物根-土复合体强度模型试验研究".岩石力学与工程学报 32.5(2013):1020-1031.