Grouting treatment of water and sand inrush into an inclined shaft in aeolian sand layer

There are widely distributed thick aeolian sand layer covering the surface of the auxiliary inclined shaft of the Jinjitan Coal Mine,Yulin,Shaanxi province. The floor of the auxiliary inclined shaft ruptured due to the repeat roll- er compaction of large tonnage vehicles on the floor during a short time,which resulted in water and sand inrush and seriously threatened the safety of the mine. Aiming at the problem of water and sand inrush of the Jinjitan Coal Mine, cement grouting treatment was implemented first and it played an important role in sealing water and sand inrush,but water inflow was not completely plugged. Then the remaining water inflow was successfully plugged by chemical grou- ting. Based on the engineering practice and model test,the reasons for the rupture of the floor,effect of the grouting treatment and reinforcement mechanism of different grout were analyzed in this paper. The results of field treatment and model test show that the cement grouting reinforced sand by tree-like propagated grout veins,the chemical grouting reinforced sand by splitting and infiltration,which is more advantageous to seal off the residual pathway of water in- flow. Therefore the combining use of cement and chemical grouts has been proved a good efficiency.