Study On Ecological Slope Protection Performance Of Vetiveria Zizanioides Based On The Fractal Theory

Based on the fractal theory,the plant-ecology theory and the theory of slope engineering mechanics,this paper studies the mechanism of vetiveria zizanioides ecological slope by numerical simulation and indoor experiment.On the basis of the fractal theory and the plant-ecology theory,the morphological model of vetiveria zizanioides root system was established,and this model was used to analyze the correlation between the fractal dimension of vetiveria zizanioides root system and its morphological parameters.On the basis of the theory of hydrological effect and mechanics effect of slope engineering,the hydrological effect and mechanical effect of vetiveria zizanioides were studied by indoor simulation experiment.The correlation between the fractal dimension of vetiveria zizanioides root system and the hydrological effect parameters and mechanical effect parameters of vetiveria zizanioides ecological slope protection technology were established.On the basis of the finite element analysis theory and the Mohr-Coulomb failure criterion,the model of the interaction between the root system and the slope soil was established.The relationship between the surface stability of the slope and the fractal dimension of the root system was studied by numerical simulation.1.The fractal dimension of vetiveria zizanioides root system gradually increases with the extension of its growth period,and they showed significant logarithm correlation.2.The maximum rainfall cutoff rate and the maximum rainfall cutoff per unit area increase with the increase of fractal dimension of vetiveria zizanioides root,and they show the significant linear positive correlation.3.The tensile force of vetiveria zizanioides root system gradually increases with the increase of root diameter,and basically remained the same with the increase of root length.The tensile strength and tensile force of vetiveria zizanioides root system decreases with the increase of the root diameter,and decreases with the increase of the length of the root system.They showes the correlation of the multivariate index.4.The cohesion and internal friction angle of the root-soil composite increases linearly with the increase of root content,and increases linearly with the increase of the root-system fractal dimension.Under the condition of confining pressure,the failure load for the different root distribution of root-soil composite is different,which is sorted in descending order by their soil-reinforcement abilities as following: complexing type,intersecting type,vertical type,tilting type.The slope stability coefficient increases linearly with the increase of root content,and increases linearly with the increase of fractal dimension.5.When the branch angle is constant,with the increase of fractal dimension,the horizontal displacement,vertical displacement and total displacement of the slope surface are reduced to different degrees.The reduction of horizontal displacement,vertical displacement and total displacement for the slope surface increase linearly with the increase of the fractal dimension.