黄土高原植物根系增强土体抗剪强度的模型与试验研究
发布时间：2018-11-05 14:18
【摘要】：为研究黄土高原植物根系固土力学机制,通过WuWaldron(WWM)模型和Fiber Bundle(FBM)模型,确定了黄土高原地区主要造林树种油松、刺槐、荆条和丁香4种植物根系对土体抗剪强度的增强作用,并用原位直剪试验对其进行了验证。应用ABAQUS有限元软件构建造林边坡稳定性分析模型,通过数值模拟的方法从边坡尺度上量化4种不同植物根系固土作用。结果表明:通过原位直剪试验的验证,发现评价植物根系对土体抗剪强度增强作用的WWM、FBM模型均存在一定的误差,因而建议进一步完善该理论模型。同时,基于原位直剪试验测定的根系对土体抗剪强度的增强作用,进行边坡稳定性分析,发现4种植物造林边坡稳定性均高于裸坡,边坡安全系数平均提高4.38%,最大等效塑性应变平均减小50.08%,最大水平位移平均减小40.83%,最大竖向位移平均减小14.84%;4种植物措施中,荆条造林措施对浅表层土体的固土效果最佳。研究结论为评价造林边坡的稳定性,揭示根系固土的力学机理提供理论基础和科学依据。
[Abstract]:In order to study the soil consolidation mechanism of plant roots in the Loess Plateau, the main afforestation tree species, Pinus tabulaeformis and Robinia pseudoacacia, were determined by WuWaldron (WWM) model and Fiber Bundle (FBM) model. The effects of four plant roots on the shear strength of soil were verified by in-situ direct shear test. The stability analysis model of afforestation slope was established by using ABAQUS finite element software, and the soil consolidation effect of four different plant roots was quantified from slope scale by numerical simulation method. The results show that there are some errors in the WWM,FBM model for evaluating the effect of plant roots on soil shear strength by in-situ direct shear test, so it is suggested that the theoretical model should be further improved. At the same time, based on the enhancement of soil shear strength determined by in-situ direct shear test, the slope stability analysis shows that the stability of the four plant afforestation slopes is higher than that of the bare slope, and the safety factor of the slope is increased by 4.38 on average. The maximum equivalent plastic strain is reduced by 50.08, the maximum horizontal displacement by 40.83 and the maximum vertical displacement by 14.84. Among the four plant measures, the afforestation measures of wattle strip have the best effect on soil consolidation of shallow surface soil. The results provide a theoretical and scientific basis for evaluating the stability of afforestation slope and revealing the mechanics mechanism of soil consolidation by root system.
【作者单位】： 北京林业大学水土保持学院;
【基金】：国家自然科学基金项目(31400616) 国家重点研发计划项目(2016YFC0501704--01)
【分类号】：S714.7
本文编号：2312336
[Abstract]:In order to study the soil consolidation mechanism of plant roots in the Loess Plateau, the main afforestation tree species, Pinus tabulaeformis and Robinia pseudoacacia, were determined by WuWaldron (WWM) model and Fiber Bundle (FBM) model. The effects of four plant roots on the shear strength of soil were verified by in-situ direct shear test. The stability analysis model of afforestation slope was established by using ABAQUS finite element software, and the soil consolidation effect of four different plant roots was quantified from slope scale by numerical simulation method. The results show that there are some errors in the WWM,FBM model for evaluating the effect of plant roots on soil shear strength by in-situ direct shear test, so it is suggested that the theoretical model should be further improved. At the same time, based on the enhancement of soil shear strength determined by in-situ direct shear test, the slope stability analysis shows that the stability of the four plant afforestation slopes is higher than that of the bare slope, and the safety factor of the slope is increased by 4.38 on average. The maximum equivalent plastic strain is reduced by 50.08, the maximum horizontal displacement by 40.83 and the maximum vertical displacement by 14.84. Among the four plant measures, the afforestation measures of wattle strip have the best effect on soil consolidation of shallow surface soil. The results provide a theoretical and scientific basis for evaluating the stability of afforestation slope and revealing the mechanics mechanism of soil consolidation by root system.
【作者单位】： 北京林业大学水土保持学院;
【基金】：国家自然科学基金项目(31400616) 国家重点研发计划项目(2016YFC0501704--01)
【分类号】：S714.7
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1 格日乐;左志严;蒙仲举;张成福;王娟;;杨柴根系提高土体抗剪特性的研究[J];水土保持学报;2014年04期
，本文编号：2312336
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