The technique of micro-seismic monitoring the height of “two zones”

It is mainly introduced that the microseismic monitoring results obtained during long-wall mining in Xinglongzhuang Colliers of China and Cordonstone Colliery of Australia, and conducted further theoretical analysis and study. The primary target of the monitoring is to dynamically determine the developing regularity, and heights of the "two zones"(caving zone and fractured zone)in roof rocks. The study results indicate that the maximum heights of the caving zones and fractured zones are not reach the aquifers above the target coal seams in the two collieries, which means the water from the aquifers above coal seams is impossible to flow into mines. This result corresponds with practical situation. Meanwhile the study results of the microseismic method are proved a reliable technique for determination of the heights of the "two zones" and dsigns of the water and sands pillars.