Research On Soil Stabilization And Slope Protection Stability Of Plant Root System In Dalian Area

Ecological slope protection is a new type of flexible protection technology,which can not only play a good supporting effect,but also take into account the landscape,economy and ecology.At present,the research and application of vegetation slope protection technology are very rich,but due to the complex geological conditions and the characteristics of plants,the quantitative research on slope protection is relatively weak,and the safety and stability calculation of vegetation slope protection has important engineering significance.The slope geology of Dalian area is mainly soft rock and gravel soil,and the representative slope protection plants are mainly Robinia pseudoacacia,Lespedeza and Amorpha.Based on the Dalian Distinguished Young Scientific and Technological Talent Funding Project(2018RJ10),this article carried out the research on the soil-fixing effect and slope protection stability of plant roots in vegetation slope protection in Dalian area.The main contents are as follows:(1)The root pull test was carried out on site.Carry out root pullout tests on typical geological slopes in Dalian area,analyze the influence of different root system conditions and planting density on pullout force,and explore the anchoring performance of root-soil composite materials.Studies have shown that the root plucking force of Robinia pseudoacacia,Lespedeza amorpha and Amorpha pseudoacacia is significantly positively correlated with root diameter,root length and soil density,and shows a trend of first increasing and then decreasing with water content and planting density,that is,it exists Optimal moisture content and planting density.(2)The indoor single-root tensile test was carried out.In order to further explore the slope protection effect of the root system itself,a single root tensile test was carried out on the basis of the field pull test.The influence of different root diameters,types and fresh weights on the breaking force was analyzed,and the tensile strength of a single root was explored.Mechanical properties.The results showed that the root breaking force and diameter of the three plants of Robinia pseudoacacia,Lespedeza chinensis and Amorpha pseudoacacia showed a power function increase,while the tensile strength and diameter showed a power function decrease relationship.Linear increase relationship,when the diameter of the three plants is 10 mm and larger,the breaking force reaches more than 1000 N.(3)Researches on the soil consolidation mechanism and slope protection stability of plant roots have been carried out.Based on the mechanical properties of root system soil consolidation obtained by root system pull-out and indoor single-root tensile test,a theoretical model of root system slope protection was established,the mechanical mechanism of root system slope protection was revealed,and three representative slope protection plants for typical geological slopes in Dalian area were proposed.Calculation method of slope safety factor under different root lengths and planting densities.Use MIDAS GTS-NX finite element software to perform numerical simulation analysis on different working conditions,and compare and verify with theoretical calculation results.The results show that there is a certain error between the numerical simulation and the theoretical result,but the overall trend is more consistent.Therefore,the accuracy of the calculation method in this paper for the safety and stability calculation of vegetation slope protection in Dalian area is verified,and it can provide a certain reference for the safety and stability calculation of vegetation slope protection in Dalian area.