首页|黄土边坡典型护坡植被的根系加固力学效应演化分析

黄土边坡典型护坡植被的根系加固力学效应演化分析

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植被防护是增强边坡浅层力学稳定性,恢复路域生态环境的重要手段.为了研究草本植物对黄土边坡的加固效应,以典型护坡植被高羊茅为例,获取其各发育阶段根系的形态参数指标,并进行拉伸试验,得到根系力学特性演化规律.此外,通过直剪试验获得了原状根土复合体的抗剪强度参数,采用响应面法分析了各因素对根系加固力学效应的影响程度,并将植物生长状况的跟踪应用于土体强度的演化解释,进而分析根系发育周期内边坡浅层力学稳定性的变化.研究结果表明:根系的形态参数指标均随发育时间而显著增大,根土间的相互作用得到提升,根系对土壤的加固效应逐渐增强,沿土层深度方向呈现出依次减弱的空间差异性;根系的抗拉力、极限延伸率、抗拉强度以及弹性模量均随发育时间呈现正相关关系,且上层根系所能提供的抗拉力最大,对复合体的力学加固效应也最强;根系可以改变土体剪切力学行为特征,增大剪切峰值强度,延长剪切峰值位移,在边坡受到剪切破坏时,能够抵抗更大的极限剪应力,并延长破坏时间,且加固效果随着坡度的提升而显著增大,法向应力、含水率、根面积比对土体的力学效应逐次增强;基于高羊茅根系,优化了 Wu-Waldron-Model根土复合体模型中的固土修正因子k,建立了更加精确量化根系固土效应的计算方法.
Evolution Analysis of Root Reinforcement Mechanical Effect of Typical Plant Protection on Loess Slope
Plant protection is important for improving the mechanical stability of shallow slopes and rehabilitating the ecological environments of road areas.To investigate the reinforcing effect of herbaceous plants on loess slopes,a typical slope-protecting plant,Festuca arundinacea,was selected as an example.Morphological parameters of root development at each growth stage were obtained,and tensile tests were conducted to assess the evolution of the mechanical properties of the roots.Additionally,the shear strength parameters of the undisturbed root-soil coupling body were obtained by performing direct shear tests.A response surface method was used to analyze the impact of various factors on the mechanical effects of root reinforcement.Furthermore,the growth status of the plants was tracked to interpret the evolution of soil strength,and changes in the mechanical stability of the shallow slope during the root development cycle were analyzed.The results show that the morphological parameters of the roots significantly increase with developmental time,and the interaction between the roots and soil is enhanced.The reinforcing effect of roots on the soil gradually increases and shows a spatial difference,which weakens along the depth of the soil layer.The tensile resistance,ultimate elongation rate,tensile strength,and elastic modulus of the roots exhibit positive correlations with the development time.The upper root system of the soil provides the maximum tensile force,and the effect of the mechanical reinforcement on the coupling body is the strongest.Roots modify the shear mechanical behavior of the soil by increasing the peak shear strength and prolonging the peak shear displacement.When subjected to shear failure,the slope can withstand a greater ultimate shear stress and prolong the failure time,and the reinforcing effect increases significantly with slope inclination.Furthermore,the extent of the influence of normal stress,water content,and root area ratio on the mechanical effects of the soil increases.Based on the roots of Festuca arundinacea,the soil consolidation correction factor k of the WWM model was optimized,and a more precise method for quantifying the soil stabilization effect of roots was established.

subgrade engineeringplant slope protectionexperimental studygrass rootme-chanical effects

包含、敖新林、高月升、兰恒星、郭冠淼、郑涵

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长安大学公路学院,陕西西安 710064

黄土科学全国重点实验室(筹),陕西西安 710054

陕西省水务集团有限公司,陕西西安 710075

长安大学地质工程与测绘学院,陕西西安 710054

自然资源部生态地质与灾害防控重点实验室,陕西西安 710054

长安大学水利与环境学院,陕西西安 710054

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路基工程 植被护坡 试验研究 草本根系 力学效应

国家自然科学基金项目国家自然科学基金项目国家自然科学基金项目陕西省重点研发计划项目陕西省科学技术协会青年人才托举计划项目西安市未央区科技和工业信息化局项目

4204100642077265419278062023-YBSF-48620220707202120

2024

中国公路学报
中国公路学会

中国公路学报

CSTPCD北大核心
影响因子:1.607
ISSN:1001-7372
年,卷(期):2024.37(6)
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