Study and application of construction technology for inclined shafts penetrating drift sand strata in coal mine

The drift sand stratum is a kind of common harmful stratum in mine construction. It is characterized by auto flow ability in water or under dynamic disturbance. Improper construction will cause the drift sand to flow to the free surface to fill the excavation space and get the shaft flooded or lead the ground to collapse. The water-holding condition and thickness of drift sand strata are determined by using engineering geological drilling and electrical prospecting technology. Based on the vertical depth of drift sand stratum, the constructing techniques for the inclined shaft penetrating the drift sand stratum are classified. A reasonable tunneling technology is presented for the inclined shaft penetrating the drift sand stratum with different thicknesses. Pressure ability of structure is calculated by means of both finite element method and analytical method. The reasonable structure of shaft lining is proposed. To evaluate the supporting effect, deformation, stress and permeability strength are monitored. The results show that the construction technology for the inclined shaft penetrating the drift sand stratum is reasonable, thus the tunneling progress and construction safety are ensured, and the structural safety and surrounding rock ability are guaranteed.