Pull-out Study Of Soil-reinforcement In The Roots Of Trees And Shrubs

With the speeding up of the national civil process,plasma spray block stone slope is widely used in slope protection construction,because the concrete protection and formation of the gray landscape and the surrounding green environment become very abrupt,therefore,vegetation and shrubs are widely used in slope protection.At present,there is still little research on the mechanism and experimental study of the slope protection of the shrub.In this paper,a large number of indoor and outdoor experiments were conducted on different root morphology,different water content and geometric parameters.The main content and conclusions are as follows.(1)The interaction force between roots and soil was studied by means of indoor drawing test.The experimental results show that the larger the radius or length of the root system,the higher the pulling force level;The friction angle decreases with the increase of surface area.The friction cohesive force increases with the surface area of the root system;The larger the loading,the more the friction coefficient of the root system increases with the increase of the surface area.(2)The interaction force between root soil in different water content,overburden load,root and soil type was studied.The experimental results show that the maximum pulling force increases linearly with the height of the plant,and the increase of the living root is greater than that of the dead root.With the increase of the root length L,the pulling force of the dead root area increases first and then decreases,and decreases with the increase of the root diameter R.The per unit area pullout force decreases with the increase of L,and decreases with the increase of R.The maximum pulling force increases with the increase of moisture content and then decreases.When the moisture content was 22%and 24%,the maximum pulling force decreases with the increase of root volume.The root system of plants has a large fluctuation in the displacement curve under different volume or water content.The root morphology has little influence on drawing parameters;The maximum pulling force of the Y-type root system and the main direct root system increases linearly with the increase of the secondary lateral root number.When the water content of the main direct root system is 10%,20%and 25%,the drawing curve is hardened,and when the moisture content is 15%,the drawing curve is softened.When the horizontal root system and the Y-type root system were at 15%and 17.5%of the water content,the drawing curve was hardened,and the water content was 20%,22.5%and 25%,and the drawing curve was softened.(3)Red clay slope is studied through field drawing symplocos anomala,pinus elliottii,photinia fraseri root system under the condition of moisture content,root volume changes,the effects of root system on soil slope reinforcement.The results showed that the slope protection effect of 1-2 year old shrubs suitable for growth in the red clay area was ranked as photinia fraseri,prunus elliottii and symplocos anomala from good to bad.