Research On Mechanical Characteristics And SuPPort Technology Of High Embankment With SteeP SloPe In V-shaPed Gully

The special topographic conditions of valleys make the failure modes and deformation characteristics of high embankment with steeP sloPe in mountainous different from ordinary embankments.It is the problem need to slove that how to understand the three-dimensional sPace effect of the V-shaped gully,and put forward the appropriate support technology.In this paper,numerical simulations,model tests and theoretical analysis are used to study the main factors of affecting the stability and deformation of high embankment with steeP slope in mountainous areas,the soil arching effect of embankments in a narrow path in the V-shaped gully,the large-scale similarity ratio model test of sands,and the support technology of embankment.The main conclusions are as follows:1.On the basis of literature and engineering research,the high embankments with steeP slopes in the mountainous area were divided into four types:polyline type fully-filled embankment,polyline type half-filled' embankment,straight type fully-filled embankment,and straight type half-filled embankment.2.The analysis results of FEM strength reduction method show that the changes of filling height and steeP slope will affect the safety factor,failure mode and deformation characteristics of embankment.If the embankment is higher,the sloPe of the steep slope of the foundation is greater,so the safety factor is lower.However,the impact of steep slopes is less.3.The steep slope gradient,the width of the bottom of the trench,the slope of the side bank,and the filling of the embankment will have different degrees of influence on the three-dimensional spatial effects of the gully topography.Compared with the two-dimensional embankment,under the effect of three-dimensional space effect of the gully terrain,the embankment fill height,steep slope,bottom width,and side bank slope increase the safety factor of the embankment by 1.12-1.16 times and 1.15-1.16 times,1.05-1.12 times,1.07-1.22 times.4.In consideration of the three-dimensional spatial effect of gully terrain,the embankment fill height increased from 20m to 40m,the deformation of three-dimensional embankment was redueed by 12%-19%compared with two-dimensional embankment;the steep slope increased from 25° to 40°,three-dimensional embankment The deformation is reduced by 11.5%to 16.7%compared to the two-dimensional embankment.Th e deformation of the three-dimensional embankment is smaller than that of the two-dimensional embankment,and the growth rate of the embankment is less than the two-dimensional embankment.5.Based on numerical simulation and theoretical analysis,it is concluded that the formation of soil arching in beam-piercing embankment is closely related to the special terrain of the gully;the soil arching effect in high embankment on the steep slope of bunched gullies mainly occurs at the bottom of the embankment.At 2-7m,both sides of the basal bank actually acted as direct arching and friction arching.The internal friction angle and cohesion of the soil ha,ve a significant effect on the formation of the soil arching effect.Increasing the internal friction angle in the range of 10°-20° favors the formation of soil arching effect.When the cohesion force reaches 15kPa,the range of soil arching effect is obviously weakened.6.Under the influence of the three-dimensional spatial effect of the rectilinear steep slope high embankment,the safety factor of the three-dimensional embankment is greater than 1.09-1.15 times the safety factor of the two-dimensional embankment;the deformation of the three-dimensional embankment is smaller than that of the two-dimensional embankment.7.Com pared with a single retaining structure,the combined retaining structure of the retaining wall and geogrid can not only improve the stability of the embankment but also effectively limit the lateral deformation of the embankment.