“Opposite-slide” loess landslides and its formation mechanism in Binchang mining area

In recent years,as the high-intensity exploitation of coal resources,the “ opposite-slide” loess landslides caused by coal mining subsidence were developed,the loess landslides usually have large scale and poor stability. Based on the field survey,this paper takes Liqian-Baixiang landslide as a case,discusses the formation mechanism of “opposite slide” landslide by numerical simulation,and summarizes the produce condition of “ opposite slide” land- slide. The result shows that in thick loess area,surface subsidence is caused by uneven migration of coal seam overly- ing bedrock. In the process of cross valley exploitation,the “opposite-slide” loess landslides is caused by the displace- ment vector of the upper loess layer to the center of the mined out area and the dynamic displacement of the downward displacement vector along the slope of the mining disturbance. And the recovery after arrived at one side of the side slope is often earlier than the arrival of first slope landslide. On one side of the slope to the same as the direction of ex- traction,the landslides are push-type landslides,the other side landslides are pull-type landslides. The pull-type land- slides are often greater than push-type landslides. There are four main conditions for the formation of “opposite-slide” loess landslides:loess slope,gully topography,mining disturbance and rainfall catalysis.