Method of determining the reasonable position of open-off cut based on abutment pressure estimation

This paper focuses on the causes of rockbursts around open-off cut through theoretical analysis and field in- vestigation. In this study,a method of determining an appropriate open-off cut position was proposed based on abutment pressure distribution. The study result shows that when the open-off cut is placed in the area under the influence of self-weight of overlying strata,the transferring stress of gob zones and tectonic stress,the superimposed stress exceeding the critical stress is the main cause of rockburst. The fracture angle of overlying strata was estimated by analyzing the field microseismic monitoring data. Combined with overlying strata spatial structure theory,an abutment pressure esti- mation model was presented. Using this model,overall superimposed stress was successfully computed and the abut- ment pressure distribution curve was also obtained. Using dynamic stress ratio as the distinguishing criterion of rock- burst risk,the rockburst risk zones can be identified according to the empirical value,providing basis for determining appropriate open-off cut position and field rockburst control intensity. The study result has been successfully applied in a coal mine in Henan Province,China.