| The average cost per kilometer of expressway is up to tens of millions of yuan.If there are landslides,avalanches,mudslides and other disasters along the highway,it will not only cause damage to the road section,but also cause huge economic losses.It will also cause casualties and affect the local economic development and people's livelihood,and the occurrence of landslide disasters in the western region will be extremely serious.Therefore,in the process of highway construction,it is very important to understand the distribution characteristic,form condition and influence factors along the line,master its development mechanism,and take effective prevention and treatment of the landslide.In this paper,the development characteristics of 12 landslides along the Qingzi Expressway are summarized,the development factors and forming mechanism are analyzed,and the typical landslide is selected for stability analysis,which has certain application value.The results of the paper are following:(1)Through data collection and field investigation and analysis,the landslide along the Qingzi Expressway is mainly distributed on the right bank of xiuyanhe,both of which are loess-bedrock landslides,and more than 75% of them are old landslides,mainly in middle-level and deep landslides,which are classified by landslide scale,and most of them are large landslide.Landslide plane form in that area is divide into three types of dustpan type,sector and m-type.Landslide section characteristics of the study showed that 20 ~ 40 ° slope range are the advantages of landslides in the area of slope toe,landslide after the wall is exposed more obvious,the wall is highly concentrated in 15~25 m,40~50 m two range,two types of landslide after the wall height is large;From the appearance characteristics,the landslides that its' s ratio of width to length is 1~2.5 is the most.From the sliding mode,the landslide in the region is sliding.(2)This paper summarizes the factors affecting the landslide development in the region,including stratum lithology,topographical features,atmospheric precipitation,groundwater,surface water,etc.,and the above influencing factors are integrated,and the mechanism of landslide formation is analyzed,and it is concluded that rainfall is the main inducing factor in landslide.Then,through the geo-studio numerical simulation software,the seepage field and stress field variation of the slope under rainfall are simulated to show the whole process of slope deformation and destruction.Meanwhile,it is found that in the deformation process of the slope,the slope body is approximately circular,with the largest deformation in the middle and the minimum deformation of the slope.(3)In this paper,the typical landslide in the region,Li wa gou landslide,is used to calculate the stability of the typical section of the landslide by using the transfer coefficient method.The results showed that under the natural condition and rainfall conditions,the landslide in the unstable to stable state.It is found from that simulation software of geo-studio numerical simulation software that the seepage field simulation and stability analysis of the rainfall operation of the typical section of the landslide are that,with the increase of rainfall time,the slope of the slope is slope to the slope foot,and the slope is moved gradually from the slope surface to the slope,the stability coefficient of landslide is gradually decrease,and in extreme rainfall,the stability of landslide is changed from the basic steady state to the understeady state.Both results show that the landslide is under the condition of low stability and basic stability under the condition of rainfall. |
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