Research On Mechanical Properties Of Vetiver Root-soil Composite

With the rapid development of social and economic, highway and railwayconstructions enter a rapid development in China. Due to the various characteristic ofthe landform, a large amount of artificial slope appear inevitably in the process ofconstruction, which destroyed the original ecological environment, and resulted in alarge number of secondary bare land, serious soil erosion, and caused serious imbalanceof the ecological environment, even appeared natural disasters, such as mountain slump,landslide and so on. The damage has brought great economic losses to the safety ofpeople’s life and property. Therefore, how to protect the environment in the highwayconstruction, realizing the sustainable development of ecological environment, is a veryimportant, and worthy of our attention. There is the traditional engineering protectiontechnology in the protection of highway slope, such as frame structure protection,masonry protection, cover, protection and retaining project, etc. But the traditionalengineering protection technology is expensive, and easy to cause environmentaldamage during the construction and use, and rock will occur weathering, concreteageing gradually, corrosion and intensity reduction of steel after years of weathering,which resulting in worse protection effect.So the ecological slope protection overcomes these drawbacks, in recent years,more and more slope protection engineering began to adopt the ecological protection,ecological protection technology combined engineering protection with plant protection.Based on slope stability, plant roots wrapped around each other in the soil, and the bondforce between roots and soil adhesion, which achieved the effect of reinforcement ofslope, and played the roles of engineering construction and environmental protection.The essence of the ecological slope protection is plant slope protection, and slopeprotection mainly through the interaction of plant roots and soil, plant roots in the soilshaped network by weaving, winding, which has definitely integrity. Plant roots issimilar to the fiber, plant roots, as the reinforced phase, formed a kind of naturalcomposite material, this natural compound materials can effectively improve thestrength of the soil, and can achieve the purpose of Solid slope.First of all, the paper simply introduces the vetiver and its application, anddiscussed the slope protection effect of vetiver grass, respectively from the mechanicseffect, hydrological effect, ecological effect and landscape effect. Secondly, this paper elaborated the basic theory of composite materials, andintroduced the definition and composition of composite materials, and then from thepoint of composite materials, took roots and soil as a natural complex compositematerials-root soil, and took soil as matrix phase of complex material, then took thedistribution of plant root systems as enhancement phase of complex material, andcontain the root soil is similar to the fiber which is reinforced brittle compositematerials, and introduced the reinforcement strengthening effect of plant roots and soilfrom the perspective of composite materials.Then, combined the slope protection of vetiver plant with composite materialtheory, root soil of composite material mechanics model is set up, using the classicallaminated plate theory, and analyzed theory of composite material mechanicsperformance for single and multi-layered soil complex, which provided a theoreticalcalculation formula for complex structure design of the root soil mechanics.Finally，We can calculate engineering constants of single root soil of complexthrough the theoretical calculation formula, and compared the theoretical calculationvalue with the experimental value, then found that the theoretical calculation value wasconsistent with the experimental results, and the error is in the acceptable range, thesafety coefficient is higher. The result showed that the formula can be used to guide theengineering and technical personnel in vetiver plant slope protection, which can avoid alarge number of test operation, at the same time, can reduce the error caused by test.Meawhile, the formula is simple and convenient, and easy to operate, has the very higheconomic benefits, and is worth of popularization.