The Studies On Geotechnical Characteristics Of Artemisia Ordosica Root-Soil Complex

In this paper,based on the principle and method of soil mechanics,we took the silty soil and the root of Artemisia ordosica(a kind of soil and water conservation pioneer shrub)as objective to investigate the effects of different factors about the friction characteristics of root-soil interface and shear properties of root-soil complex.The research results are as follows:There was a linear positive correlation between the direct shear friction strength and the vertical load of the root-soil interface of Artemisia ordosica and silty sand.The frictional strength of the root-soil interface increases with the increase of the vertical load.The growth rate of the frictional strength is different under different vertical loads.The larger the vertical load,the greater the growth rate of the root-soil interface relative to the soil-soil interface.The direct shear friction strength and cohesion of the root-soil interface under pore water confined condition are less than that under pore water unconfined condition.The friction coefficient of pore water under confined condition is greater than that under unconfined condition.The frictional resistance of the root-soil interface decreases with the increase of shear rate.The pull-out frictional resistance of Artemisia ordosica increased with the increase of root diameter,and the pull-out frictional strength decreased with the increase of root diameter.The soil consolidation efficiency of fine root unit root diameter was stronger than that of coarse root.The effect of loading rate on the drawing friction strength is not significant.The strength and residual shear strength of the root-soil complex of Artemisia ordosica were linearly positively correlated with the vertical load.The greater the depth of the burying root,the lower the soiling efficiency.The strength and cohesion of the root-soil composite under the condition of soil pore water pressure is less than that of the soil pore water.The internal friction angle and the residual friction internal angle are positive growth rates under different soil pore water pressure conditions.The strength characteristics of the root-soil composite increase with increasing root diameter.The shear rate has no significant effect on the strength characteristics of the root-soil composite.The effect of soil water content on the geotechnical characteristics of the root-soil complex of Artemisia ordosica was as follows:the friction resistance,cohesion and root-soil composite strength and cohesion of the root-soil interface increased first and then decreased with the increase of water content.The trend reached the maximum at the dominant moisture content(11.94%);the root-soil friction coefficient and the root-soil composite friction angle decreased with increasing water content.