Stability Analysis Of Slope Strengthened By Plant Roots In Zhenjiang Area

As an engineering technology,slope vegetation has been widely applied in slope protection,but its theoretical research lags behind the application of engineering practice.Especially,there are few articles reported about straight comparison between the slope reinforced by roots and the the shallow reinforced slope.Because of this situation,this article conducts exploratory research.Firstly,based on the achievements of many scholars,this article summarizes the mechanical mechanism of soil reinforcement by vegetation roots.Secondly,taking the Chimonanthus praecox root of zhenjiang area as the research object,and the shear strength of samples which contain vegetation roots or do not contain vegetation roots can be obtained by indoor direct shear text,so that the contribution of roots to the increase of slope stability coefficient can be obtained.Thirdly,further based on the results of the text,using ABAQUS finite element software,we establish model of shallow reinforced slope and model of slope reinforced by roots.Finally,using the stability of shallow reinforced slope as a reference,and the shallow reinforcement range is 2m depth in the vertical direction of the inclined slope,so that under the same slope stability condition,the root parameter design of root reinforcement model can be obtained by inversion.This article mainly through three factors of chimonanthus praecox root to design the root parameters of root reinforcement model,three factors are root reinforcement position,whether there are lateral roots and vegetation numbers.Then,taking the slope safety factor calculated by strength reduction method as evaluation to perform inversion analysis,in order to make the slope fixation effect consistent with the model of shallow reinforced slope.The mian results are as follows:(1)Systematically summarize the mechanical mechanism of vegetation root reinforcing soil,containing root reinforcement theory,anchorage theory and root-soil interaction mechanical model,it covers the reinforced mechanical model of herbaceous plants on the surface of slope and the anchorage mechanical model of woody plants on the slope.(2)The shear text results show that,compared with the samples without vegetation roots,the displacement of samples containing roots increased by about 22.23% when shear failure occurred.This shows that the existence of roots can improve the ductility of soil,delay the shear failure time of soil,and to a certain extent,improve slope stability.(3)Obtained by numerical simulation analysis,the optimal solid slope position of single vegetation root with lateral roots is 0.05 L from the base of slope.In addition,the scope of the effect of the vegetation root with lateral roots on reinforcing the slope is approximately 0.3L near the base of slope,compared with roots without lateral roots,the regional scope of the reinforcement effect increased by approximately 0.15 L.This shows that the presence of lateral roots has a significant effect on enhancing soil consolidation range.(4)The first tree planted at the base of the slope makes the greatest contribution to improving the slope stability,and the stability safety factor of the slope increases as the number of root on the slope increases,In a certain range of the beginning,the slope safety factor increases in direct proportion with the increase of the root number,but when the root content in the soil reaches a certain degree,the safety factor of the slope will no longer increase,and it will tend to a constant value.(5)Obtained by numerical simulation inversion analysis,when the reinforcement position of root with lateral roots and the number of planted vegetations are reasonably arranged on the slope reinforced by roots,this will make the safety factor of slope reinforced by roots be basically identical with the shallow reinforced slope,so that they can achieve equivalent solid slope effect.