农业工程学报Issue(4)：142-149,8.DOI:10.11975/j.issn.1002-6819.2016.04.020
模拟自然降雨条件下植物根系增强边坡土体抗剪强度特征
Characteristics of slope soil shear strength reinforced by vegetation roots under artificially simulated rainfall condition
摘要
Abstract
Xining Basin which is located at the conjunction of the Loess Plateau and the Qinghai-Tibet Plateau is selected as the testing area, and the artificially simulated rainfall test and the washout test are carried out on the slopes with the monocultures ofCaragana korshinskiiKom.,Zygophyllum xanthoxylon (Bunge) Maxim.,Elymus nutans Griseb, and Agropyron trachycaulum (Linn.) Gaertn, separately, and with the mixed planting ofC. korshinskii andA. trachycaulum, as well asC. korshinskii andE. nutans. And there are denuded slopes there. Based on the artificially simulated rainfall test, the direct shear test is carried out systematically to analyze the influence of the rainfall on the shear strength and the corresponding shear strength variation regularity of 3 different soil layers. The result shows that before the artificially simulated rainfall test, the cohesion force of the soil in layer a(0-20 cm) mixing planted withC. korshinskii andA. trachycaulum, as well asC. korshinskii and E. nutans is 19.5 and 18.9 kPa respectively, which is larger than that for the soil layera on the slope planted with the single plant under the same condition. The cohesion force for the soil in layerb (20-40 cm) on the slope planted with vegetation is larger than that of the denuded slope. And the difference of the cohesion force for the soil layerc(40-60 cm) between the planting slope and the denuded slope is not significant. After the artificially simulated rainfall test, the composite cohesion force of soil layera on the mixed planting slopes is greater than that of the bare slopes. The composite cohesion force amplitude of the soil layer a on the 2 kinds of mixed planting slopes is greater than that of bare slopes, with an increase of 30.65%-56.45%. The increased cohesion force amplitude of soil layer a with the monocultures is 4.17%-38.89%, and that of layer b on the slopes with the mixed planting is 29.17%-34.72%. The cohesion force increased amplitude of soil layerc is significantly less than that of layera and layer b, which means that the herb roots play a role in soil reinforcement in the shallow layer and the shrub roots play a role of anchorage in the relatively deeper soil layer. The research has theoretical and practical significance in the further study on the mechanism of shear strength improved by plants under the condition of natural rainfall in loess area, as well as in preventing geological disasters such as water and soil loss on slope and shallow landslide.关键词
土壤/生长/降水/寒旱环境/植物边坡/模拟降雨/复合体抗剪强度/根-土复合体Key words
soils/growth/precipitation/the cold-arid environment/slope planted with vegetation/artificially simulated rainfall test/shear strength of root-soil composite system/root-soil composite system分类
农业科技引用本文复制引用
李华坦,李国荣,赵玉娇,胡夏嵩,刘昌义,朱海丽..模拟自然降雨条件下植物根系增强边坡土体抗剪强度特征[J].农业工程学报,2016,(4):142-149,8.基金项目
国家自然科学基金资助项目（41162010）；教育部“长江学者和创新团队发展计划”创新团队研究计划资助项目（IRT13074）；青海省重点科研攻关资助项目 （）
