The Study of Processing Large Cavity based on One Time Raise Driving Technology

• 1、School of Resources and Safety Engineering， Central South University， Changsha 410083

Abstract：Cavitiy is one of the serious problems during mining operation, especially those unmapped and unaccessible ones under open pit benches, these cavities which were lefted by former underground mining severely threatened the personnel and equipments on benches. A ruggedized small laser scanner can be used through borehole to obtain a very clear visual 3D model of the cavity such as the size, the shape and the orientation of the cavity in a very short time. These detailed datum of cavity are essential for later planning of disposal no matter what disposal method will be selected. A large cavity under Sandaozhuang open pit bench were chosen to study the disposal scheme. Based on the detected 3D datum by laser scanner, the one-step shaft formation technique was employed to form a large-diameter shaft in cap rock above the cavity, and this shaft will be used as compensation space for later blasting. This proposed method will provide reference for other cavity disposal in large size.

Keywords： open pits cavity laser 3D scanning one-step shaft formation deep hole blasting