The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

384 / 2018-08-13 19:40:27

Prediction and prevention measures of rockburst proneness in ultra deep shaft excavation

Excavation of ultra deep shaft，rockbursts，Ground stress monitoring，prevention measures

Mine Dynamics Disaster > Rock burst impact

Aimed at the occurrence of rock burst in super-deep shaft（A digging into a well depth of not less than 1200m of the shaft） after it is excavated certain depth, a monitoring system of crustal stress-displacement of shaft lining is established to predict the occurrence of rock burst, and the stability of surrounding rock of shaft is analyzed and studied.In order to measure the variation of crustal stress, the pressure gages and displacement sensors are installed at different depth of shaft. Based on the analysis of stress variation curves at four points arranged at different depths around the shaft lining, the distribution law of crustal stress is summarized.In the 4# position(70°S E), the measured pressure is the largest, the maximum horizontal principal stress can reach above 120MPa, and its orientation is consistent with the direction of the maximum principal stress. The displacement of the borehole wall is relatively stable during the monitoring period, and there is no sudden increase, indicating that the rockburst has the characteristics of suddenly failure.Combined with the analysis of rock-burst phenomenon in shaft engineering and the characteristics of rock-burst occurrence, the engineering measures to prevent rock burst are given, which provide scientific basis for the construction of this kind of engineering to formulate rock burst prevention measures.