摘要
植物根系护坡工程措施对黄土边坡稳定性的提升及生态环境保护具有重要作用。采用大型直接剪切仪测试了原状刺槐根系复合土体的抗剪强度,并采用FLAC3D岩土工程数值计算软件分析了不同生长年限的刺槐根系对黄土边坡的加固作用。结果表明:植物根系通过其对土体的加筋锚固作用,使根系复合土体的抗剪强度指数显著提高,抗剪强度规律符合摩尔-库伦强度准则;根系复合土体的抗剪强度随根系生长年限的增加而增大,3~7 a生刺槐的原状根系复合土体的黏聚力(c)和内摩擦角(φ)分别在44.46~88.91 kPa和23.89°~28.85°之间,7 a生刺槐根系复合土体的抗剪强度最大,c和φ分别比无根土体提高了211%和31%;植物根系对边坡具有一定的加固作用,提高了黄土边坡的稳定性,使边坡不易发生滑动,但由于刺槐根系加固土体的深度较浅,植物对边坡的加固作用有限,相较于无刺槐的黄土边坡,7 a生刺槐根系对边坡稳定安全系数的提升也仅为9%。研究成果可为刺槐等植物护坡工程的设计和施工提供科学依据。
Plant slope protection measures play an important role in the improvement of loess slope stability and the restoration of ecological environment. Here, the shear strength of undisturbed Robinia pseudoacacia root composite soil was measured by a large direct shear device, and the reinforcement effects of Robinia pseudoacacia root system with different growth years on loess slopes were analyzed by the geotechnical engineering numerical calculation software FLAC3 D. The results show that the plant roots can improve the shear strength of root composite soil significantly because the root system plays the role of reinforcement anchoring in the soil, and the shear strength of root composite soil conforms to Mohr-Coulomb strength criterion. The shear strength of root composite soil increased with the increase of root growth years, the cohesion(c) and internal friction angle(φ) of 3-7 a Robinia pseudoacacia undisturbed root composite soil were 44.46-88.91 kPa and 23.89°-28.85°respectively, and 7 a Robinia pseudoacacia root composite soil had the highest shear strength, its c and φ were 211% and 31% higher than rootless soil respectively. Plant roots can strengthen the loess slope and improve its stability, make it less prone to displacement;however, due to the shallow depth of the soil reinforced by the Robinia pseudoacacia root system, the reinforcement effect on the slope is limited. Compared with the loess slope without the planting of Robinia pseudoacacia, the improvement of the safety factor of the 7 a Robinia pseudoacacia root system on the slope stability was only accounted for 9%. The research results can provide a technical support for the design and construction of control measures of plant slope protection such as Robinia pseudoacacia.
作者
雷磊
万昊
江涛
师一卿
吕平海
田堪良
王晓东
杨傲秋
LEI Lei;WAN Hao;JIANG Tao;SHI Yiqing;L Pinghai;TIAN Kanliang;WANG Xiaodong;YANG Aoqiu(Electric Power Research Institute of State Grid Shaanxi Electric Power Company Limited,Xi'an 710100,China;State Grid(Xi’an)Environmental Protection Technology Center Company Limited,Xi’an 710100,China;State Grid Shaanxi Power Company Limited,Xi’an 710048,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China)
出处
《水资源与水工程学报》
CSCD
北大核心
2022年第5期183-188,199,共7页
Journal of Water Resources and Water Engineering
基金
国家重点研发计划项目(2017YFC0504703)
陕西省科技统筹创新工程计划项目(2013KTDZ03-03-01)。
关键词
植物根系
黄土边坡
根系复合土体
抗剪强度
边坡加固
稳定性分析
plant root system
loess slope
root composite soil
shear strength
slope reinforcement
stability analysis
