Evaluation And Mitigation Measures Of Landslide Stability In Chaoyang Village,Qianguo County,Songyuan City

Chaoyangcun landslide in Songyuan city is situated on the left bank of Songhua River and the distance between slide and river is 1.5km.The landslide is located in wavy platform,the front of which is the terrace of Songhua River alluvial valley and whose posterior is erosion accumulation wavy platform.As a whole the terrain is low.Since the beginning of the landslide sliding in August 2000,the sliding velocity continues to accelerate,the scope of the slide body is extending and the volume of the landslide is about 1300 thousand m~3,which belongs to a large landslide and becomes a direct threat to more than 100 households in their life and property.At the same time,the residents who lived in dangerous areas now were threaten by the gully catchment with the form of high sediment flood.The serious economic losses were caused each year,so that the landslide comprehensive treatment is very urgent.According to the geological model,the landslide deformation and destruction characteristics,the sliding mechanism of the Chaoyangcun landslide is clarified.The landslide rock is strongly weathered,the rock mass is weak and broken,and the appearance of soft mudstone is basically consistent with the inclination of the slope.There are obvious long-term water encroachment in mudstone strata,with many tawny rust marks mingled.The sliding surface is speculated about weak bedding mudstone surface landslide and the sliding surface form is gently inclined.On November 23,2013,many earthquakes of magnitude 4.5 or above continuously occurred in Qianguo county,obvious tremors were felt in management area.The earthquakes may destroy the balance between rock and soil groups,and become an important inducing factor of landslide geological disasters.By using the limit equilibrium method and the finite element strength reduction method and considering the influence factors of slide,the landslide stability is analyzed and concluded that the slide in storm conditions is less stable and in earthquake condition is unstable.On this basis,put forward the mitigation measures of the landslide,including comprehensive measures for retaining such like the anti-slide pile(sheet-pile retaining wall),intercepting drainage canal,crack filling,anti-scour drainage canal,and protection embankment.