Study on the Deformation Features of the Controlling Crack T10 at the Back Edge of Wangxia Dangerous Rock Area in Wushan County

In August 2010, serious deformation occurred in the Wangxia dangerous rock mass. It formed a large dangerous factor for the local resident and channel safety. Based on the detailed investigation of the crack, deformation history, GPS observations and crack displacement monitoring data analysis, analysed comprehensively the deformation of Crack T10 and relationship with the dangerous rock. The results show that Crack T10 is controlling crack and the back edge of the deformation zone. Each segment of the crack was mainly on settlement during aggravation deformation period. East and west segmentation of the crack was mainly on settlement during gentle transition period, but the tension deformation of the middle segmentation was stronger than settlement deformation. The dislocation of each segment was not obvious. This was mainly caused by the crack extension direction different from the overall deformation direction of the rear edge of the dangerous rock, and controlled by the deformation direction of the rear edge collapse pits. Crack T10 was closely associated relation with the dangerous rock mass and the deformation had bigger effect with the old cracks and mining activities at the bottom. Crack T10 also was the key area to react the dynamic deformation and failure of the dangerous rock. And also can provide efficient accurate real-time information for the warning forecast work of Wangxia dangerous rock. According to the geological conditions and the deformation character of Crack T10, think Wangxia dangerous rock is subsided extrusion type collapse.