Numerical Simulation Of Root-soil Composite Based On ANSYS

With the rapid development of economy in recent years,various water conservancy and highway projects have gradually arose,yielding many engineering slopes,which have increasingly damaged the ecological environment.People began to pay more attention to green ecology gradually,and replace the traditional engineering slope protection with plant slope protection.Based on the above background,the direct shear test of root-soil composite with Festuca arundinacea was carried out in laboratory in this paper,and the effect of water content on shear strength of root-soil composite was studied and analyzed.Taking the root-soil complex of tall fescue as an example,the effects of plant roots on soil stability under different factors were studied and discussed,which laid a foundation for the theoretical study of plant roots ecological slope protection.In this paper,by combining the shear test of root-soil composite with the establishment of finite element model,the following work has been carried out and conclusions are drawn:(1)The existence of plant roots can improve the shear strength of soil.The shear strength of root-soil composite is greater than that of rootless soil under the same water content.The shear strength of rootless soil and root-soil composite increases first and then decreases with the increase of water content.The shear strength of rootless soil and root-soil composite is the highest when water content is 17.95%.(2)The shear strength of root-soil composite decreases with the increase of soil depth.The shear strength of 0-5 cm soil depth is the largest,and that of 10-15 cm soil depth is the smallest.Through the determination of root content in different soil depths,it was found that with the increase of soil depth,the root content became less and less.It was concluded that the shear strength of root-soil complexes decreased with the increase of soil water content.(3)By simulating the diameter shear test of root-soil complex under different root length and root diameter,it was found that the shear strength of root-soil complex increases with the increase of plant root length.When the plant root length increases from 5 cm to 15 cm,the cohesion and internal friction angle of soil increase by 0.849 KPa and 0.08 degree respectively.The shear strength increases with the increase of root diameter.When the root diameter increases from 1.5 mm to 3.93 mm,the cohesion and internal friction angle of soil increase by 0.48 KPa and 0.07 degree respectively.(4)By simulating the slope soil,it is found that the existence of plant roots can improve the stability of slope soil.With the increase of root diameter,the maximum displacement of slope soil deformation decreases gradually,and the stability of slope soil was strengthenedgradually.When the root diameter increases from 1.5 mm to 3.93 mm,the stability coefficient of slope soil increases by 11.16%.With the increase of root length,the maximum displacement of slope soil deformation decreases gradually,and the stability of slope soil strengthens gradually.When the root length increases from 5 cm to 15 cm,the stability coefficient of slope soil increases by 12.16%.