Research and practice of mining technology for sealed pressure hydrologic borehole without unsealing

The long-term hydrological observation hole of the Ordovician limestone aquifer in Shandong Xinhe Mining Co., Ltd has a wide range of coal pillars, affecting the exploitation of adjacent coal resources. For this reason, referring to the movement law of overlying strata on the surface of this mine and its adjacent Tangkou coal mine, the damage degree of borehole was analyzed from the three mechanical angles, that is axial tension and compression, radial extrusion and radial shear. Combined with the changes of hydrogeological conditions such as water enrichment of main aquifers around the boreholes, the safety and feasibility of the mining without opening the borehole were analyzed and evaluated. The research results show that the boreholes without opening will not lead to borehole water accident, nor change the hydrogeological conditions of coal mining, and finally the safe mining is achieved.