Variable actual stiffness of guides in potash mine shafts

Abstract

The article addresses serviceability of reinforcement in vertical mine shafts. The mathematical framework is presented for the dynamic processes in the capsule–reinforcement system. The main causes of the dynamic loads in the capsule–reinforcement system are discussed. The importance of the processes in the capsule–reinforcement system during movement of hoists in vertical mine shafts is emphasized. It is asserted that solely computational methods are not enough to analyze processes inside the capsule–reinforcement systems in shafts. It is required to examine actual parameters of shaft reinforcement, in particular, the actual stiffness of shaft guides. The actual measurement procedure of guide stiffness in potash mine shafts is presented. The full-scale tests data are set out in connection with the actual step of reinforcement in shafts. The actual and calculated values of stiffness of shaft guides are compared. Based on the obtained results, the variable stiffness coefficient is derived for the shaft guide stiffness for a few alternative of reinforcement step. Considering the described research findings and the many years-long experience gained in operation of mine shafts, the authors have drawn a conclusion on the necessity to take into account the factor of variable stiffness of guides in shaft design and construction in potash mines in the Upper Kama Potash–Magnesium Salt Deposit, especially in case when the shaft reinforcement step exceeds the project design standards.