Determination of the Required Strength of Artificial Roof for the Underhand Cut-and-Fill Mine Using Field Measurements and Theoretical Analysis

For the underhand cut-and-fill mining method, to ensure safe and economic mining, a key issue is correctly determine required strength of artificial roof made cemented paste backfill (CPB). However, determination typically based on historical experience analytical beam formulas, resulting in obtained being unsuitable for actual situation. Therefore, order CPB reasonably accurately, field measurements sensors were proposed carried out Jinchuan mine, then formulas thick plate theory derived verify measured results. The results show that by measurement 0.325 MPa 0.304 MPa, with an error 6.78% between them, verifying accuracy measurements. standard currently used 0.59 which far exceeds optimal many additional, unnecessary expenses. To economical span drift was enlarged from 5.0 m 6.0 current production status mine. maximum cumulative subsidence 11.69 mm convergence deformation sidewalls 8.34 mm, indicates stability span-enlarged satisfactory. Meanwhile, enlarging allows 20% increase capacity per cycle. This method theoretical analysis model can be as efficient guide facilitate design mining.