Effect Research And Evaluation Of Slope Protection For Herbs In Different Soil Types

Recently years, With the rapid development of slope protection technology,its advantage in increase the stability of the slope and restoration of the ecological had got a very good expression. But there is very short time for slope protection using in the modern highway construction, and there are a lot of question of slope protection theory and application must be solved. For example, this technology can not combined with the location geology, climate of the highway, just imported foreign species or "new"、"strange" species, consider a single plant ecological habit and don’t consider the competition between species, as well as the influence of different regions and climate condition. So, although got better early results and landscape effect, a large number of plants dead or deteriorated because it cannot well adapt to the local environment. From the point of view of the long-term such slope protection engineering doesn’t have the sustainable, influence highway slope protection of long-term effects.Our country region is wide, and there are a lot differences between each region. The regional divisions of highway include the northern permafrost regions、the eastern wet season frozen area、the Loess plateau dry wet transition zone、the southeast warm area、the southwest tide warmer area、the northwest arid area、Qinghai-Tibet frigid area. The experimental field of this paper is in Harbin city which in the eastern wet season frozen area, we select three representative soil:clay(A)、silty clay(B) and sandy soil(C) as basis soil, and plant Medicago sativa L.、Coronilla varia L.、Bromus inermis L.in every soil. After the analysis of the theory of slope protection、choosing principle of vegetation slope protection and the rain on the slope erosion process, we got index system through goal-level method. Analysis the ecological adaptability and view result of three plants; through the direct shear test, analysis the shear strength of three plants; through pull out tests, analysis the resistance to pull force of three plants; Based on fuzzy neural networks selected the best soil-plants collocation program. Provide the reference for the local highway slope protection engineering construction. The specific content as follows:(1)Through the observation, got the germinate condition, growth rate, coverage, resistant, resurrected rate and other ecological adaptability indexes for the herb.(2) Through pull out tests, got the resistance to pull force of plants.(3) Try not to damage in primary state soil, sampled soil with cutting ring, then through the direct shear test, got the shear strength of plants, and further got the stick together force (c) and internal friction angle (f) to evaluate the ability to hold soil of herbs.(4)According to the result of the test, Based on fuzzy neural networks selected the best soil-plants collocation program. Through the analysis we got, we should select the most suitable herbs for different soil: for the clay (A), Coronilla varia L. is the best slope protection plant; for the silty clay (B) and sandy soil(C), Bromus inermis L.has the best slope protection effect. Medicago sativa L. has bad performance on stress resistance and the plants growing condition is poor, so the evaluation of slope protection is not ideal.