Study on structural parameter optimization in the stope combination of open pit and underground mining

The parameters setting of the top pillar and stope structure is related to the safety and resource recovery rate of the combined mining of open pit and underground mining, setting of stope structure parameters with scientific method has important engineering value. With the engineering background of a mine open pit and underground combined mining, this article is based on the theoretical analysis calculation stope width of foundation, combined with the relevant research results and mining practice, gives design of 12 kinds of boundary roof column and stope width combination scheme, using the FLAC3D data calculation software to simulate and analyze the displacement, shear strain increment and plastic zone change of the key monitoring points in the process of stepwise mining.. The results show that with the boundary pillar thickness increasing, the width of stope can be increased, but increases to a limited extent, stope limit width of 18m, mine optimum plan of the pillar 50m and stope width of 15m, the second plan follows with 30m pillar and 15m wide stope.