Abstract: According to the curtain leakage phenomenon and the drainage test results in Zhangmatun iron deposit grout curtain， the seepage channel formation process was studied through the microseismic activities induced by the collapse of the curtain and its surrounding rock masses. Results showed that the formation of seepage channel is mainly affected by the distance between mining activities and the grout curtain. The periodically mining activities， close or away from the grout curtain， lead to periodical stress changing in the curtain and the surrounding rock masses， thus resulting in the periodical activation of microseismic activities surrounding the curtain. Because the formation of water seepage channel and its development are accompanied by a large number of microseismic events， the location of the seepage channel， its formation process and related mechanism can be well determined and understood by microseismic monitoring technique， which is a promising method for the stability assessment of the grouting curtain.

Key words: microseismic monitoring, grout curtain, seepage channel, drainage test, rock failure