基于分形理论的香根草生态护坡性能研究

发布时间：2018-08-26 13:13

【摘要】：本文基于分形理论、植物生态学理论和边坡工程力学理论等多种护坡理论,通过数值模拟和室内试验对香根草生态护坡性能的机理进行研究。基于分形理论和植物生态学理论建立香根草根系的形态模型,结合香根草根系的形态模型分析香根草根系的分形维数与其形态参数的相关关系。基于边坡工程的水文效应理论和力学效应理论,通过室内模拟试验对香根草生态护坡性能的水文效应和力学效应进行试验研究,建立香根草根系的分形维数与香根草生态护坡性能的水文效应参数和力学效应参数的相关关系。基于有限元分析理论和摩尔—库伦破坏准则建立香根草根系与边坡土体相互作用的模型,通过对模型的数值模拟计算探究边坡表层稳定性与香根草根系分形维数的相关关系。(1)香根草根系的分形维数随着其生长期的延长而逐渐增大,两者呈现显著的对数相关关系。(2)最大降雨截留率和单位面积最大降雨截留量随着香根草根系分形维数的增加而增加,且呈现显著的线性正相关。(3)香根草根系的抗拉力随着根系直径的增大而逐渐增大,随着根系长度的增加基本保持不变;香根草根系的抗拉强度与抗拉力均随着根系直径的增大而减小,随着根系的长度增大而减小,且呈现多元指数的相关关系。(4)根土复合体的粘聚力和内摩擦角随着含根量的增加呈现线性增加的趋势,随着根系分形维数的增加也呈现线性增加的趋势。在围压一定的条件下,不同根系分布方式的根土复合体的破坏荷载存在差异,具体表现为混合型相交型竖向型倾斜型;边坡稳定系数随着含根量的增加呈现线性增加趋势,随着分形维数的增加也呈现线性增加趋势。(5)在分支角度一定时,随着分形维数的增加,边坡表层的水平位移、竖向位移和总位移均有不同程度地降低,边坡表层的水平位移减小量、竖向位移减小量和总位移减小量与分形维数呈现显著性的线性相关关系。
[Abstract]:Based on fractal theory, plant ecology theory and slope engineering mechanics theory, the mechanism of Vetiver ecological slope protection was studied by numerical simulation and laboratory test. Based on fractal theory and plant ecology theory, the morphological model of Vetiver root system was established, and the correlation between the fractal dimension of Vetiver root system and its morphological parameters was analyzed. Based on the hydrological effect theory and mechanical effect theory of slope engineering, the hydrological and mechanical effects of Vetiver ecological slope protection were studied through indoor simulation tests. The correlation between the fractal dimension of Vetiver root system and the hydrological and mechanical effect parameters of the ecological slope protection performance of Vetiver was established. Based on the theory of finite element analysis and the Moorn-Coulomb failure criterion, a model of the interaction between root system and slope soil was established. The correlation between the surface stability of slope and the fractal dimension of Vetiver root system was studied by numerical simulation. (1) the fractal dimension of Vetiver root increased with the extension of the growth period. There was a significant logarithmic correlation between them. (2) the maximum rainfall interception rate and the maximum rainfall interception per unit area increased with the increase of fractal dimension of Vetiver root system. And there was significant linear positive correlation. (3) the tensile strength of Vetiver root increased gradually with the increase of root diameter, and remained unchanged with the increase of root length. The tensile strength and tensile strength of Vetiver root decreased with the increase of root diameter, and decreased with the increase of root length. (4) the cohesive force and the angle of internal friction of the root soil complex increase linearly with the increase of root content, and the fractal dimension of root increases linearly with the increase of root fractal dimension. Under certain confining pressure, the failure load of root soil complex with different root distribution modes is different, which is shown as mixed intersecting vertical inclined type, and slope stability coefficient increases linearly with the increase of root content. (5) with the increase of fractal dimension, the horizontal displacement, vertical displacement and total displacement of slope surface layer are decreased to some extent with the increase of fractal dimension. (5) with the increase of fractal dimension, the horizontal displacement, vertical displacement and total displacement of slope are decreased to some extent. The horizontal displacement, vertical displacement and total displacement decrease of the surface layer of the slope show a significant linear correlation with the fractal dimension.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948;U416.14

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