Water Control and Effect Evaluation in Annular Space of Freezing Shaft Hole

If the shaft construction adopts full deep freezing method after the frozen wall thawing, the annular space between inside and outside the freezing hole easily becomes water channel, which is a serious threaten to mine safety. The west air shaft in Qianyingzi Coal Mine is constructed by full freezing method. When the shaft constructs to the well bottom sump, the upper local aquifer thaws out of the water, the total yield reaches to 25 m³/h. As large amounts of water rock runs off, one side of shaft bottom upwards along the freezing hole caving forms a big hole. Through the research analysis, point-to-point lacerate grouting and deep hole grouting by subsection were used, which effectively governed the annulus water in freezing hole. The water channel is also plugged obviously and the surrounding rock is reinforced, so shaft total yield dropped below 0.5 m³/h.