Slope Efficiency Of Five Kinds Of Shrub Root Protection On Ning-Hang Expressway

Through the survey and research on the current situation of greening of Ning-Hang Highway, the paper set the sample plot on the side slope of highway which was open to traffic.Choose five kinds of shrubs which have the same site condition and which is most representative, research on root system architecture, determination of root morphology(root length, root volume, root weight, root length density, root volume density), root tensile strength and shear strength.Investigate the effects of ecological protection of five kinds of shrubs to highway side slopes.Inorder to provide theoretical support and practice reference for further highway's greening design and construction. The main research aspects and results as follows:(1)Described five kinds of root's configuration;Described five kinds of root's distribution from root length, root volume, root weight, root length density and root volume density which is most relative to root reinforcement of soil, analysis and comparison five kinds of shrub root's capability from root's configuration and root's morphology.The results showed that, Hibiscus mutabilis's root length, root volume and root weight index are significantly greater than the other four kinds of shrubs. The indexes of Photinia serrulata are significantly lower than the other four kinds of shrubs.(2)Determine five kinds of shrub root's tensil strength through single root's pullout test, make constrastive analysis of five kinds of shrub roots's tensil strength.The results shows that Indigofera pseudotinctoria root's tensil strength is significantly greater than Cassia corymbosa. Hibiscus mutabilis and Cassia corymbosa root's tensil strength is significantly greater than Nerium indicum and Photinia serrulata.(3)Through shear test on compound body of roots and soil, measured the indexs that compared with the quadrat without roots, five kinds of shrubs all significantly improved the soil's slip resistance.Of which Nerium indicum is the max influences to the soil.(4)Composite the index of root configuration, root morphology and root mechanics, Hibiscus mutabilis have the greater index in five kinds of shrubs, and the more effcctive ecological protection to the side slop of highway. The differences of Indigofera pseudotinctoria, Nerium indicum and Cassia corymbosa are not significant. The compand index of Photinia serrulata is significantly lower than the other four kinds of shrubs.