Study On The Evolutionary Characteristics And Mechanism Of Yehu Alley In Hei Fangtai

The development of geological disasters on the loess slope section of the loess platform severely threatens local roads,factories and other public facilities and residents' personal safety.Due to the lack of research and the difficulty of control,geological disasters in the Hei Fangtai area have always been a major issue to be resolved.Based on this,this paper takes the slopes of both sides of the Yehu valley as the research object,makes full use of the regional geological data,and uses geological analysis of the evolution process,numerical calculation and analysis,multi-period earth image analysis,indoor experiments and other analysis methods combined to make a study on deformation failure modes and mechanisms of the slopes on both sides and the overall evolution of Yehu valley.And preliminary results were obtained,which are of important reference significance for the prevention and control of the associated geological disasters in the evolution of the Loess Valley.The main conclusions are as follows:(1)Through the analysis,it is found that the impact of slope contact surfaces on the slopes of the two sides of the Yehu valley can be neglected,and the occurrence of bedrock is more important.Through the intersection relationship between the occurrence of bedrock and the free surface,there are two big types of slope structure types on both sides of the Yehu valley;the left bank is the bedding slope,and the right bank is the reversal type.(2)The reasons for the differences in slope deformation characteristics between the two banks are different at different sections in the two bank slopes.By comparing the types of slope structures and the deformation and destruction characteristics of the slopes,it is found that there is a connection between the two;the occurrence of bedrock has a great influence on the stability of slope,and the bedding slope is easier to deform and damage than the reverse slope.The left bank is a bedding slope,so the deformation is mainly landslide,the right bank is an inverted type,and the slope deformation is mainly collapse.(3)The characteristics of the slope deformation on the left bank of the Yehu valley are regular in the longitudinal direction.The types of deformation are from loess-basement landslides,loess-silt clay landslides to loess landslides.This change is related to the exposed thickness of bedrock.The pure loess slope with unexposed bedrock has good stability,and its deformation and destruction process is slow.When the exposed thickness of bedrock is large,the stability of the slope is very poor.The upper soil are easily driven by the bedrock and pulled and cracked to cause damage.(4)There are multiple models for the evolution of the Yehu valley,of which the evolution of the slopes on both banks to change the width of the ditch is the most important evolutionary method;in the evolution of the ditch width,the landslide is the most significant and the fastest.(5)There are differences in the evolution of the left and right banks of the Yehu valley,and the evolution speed of the left bank is significantly greater than that of the right bank;the reason for the difference is different from that of the slope structure,resulting in the difference in the evolution patterns and strengths of the slopes on both sides.