Stress and energy criteria for coalburst in gob-side roadways with thin-pillar: Theory and practice

Coalburst is a dynamic disaster that mainly occurs around roadways and poses a serious threat to safe coal production. To quantify the coalburst risk of gob-side roadways with thin coal pillars, this study establishes an analytical model for the coordinated deformation system of the roof-coal pillar-coal seam. Based on the critical state of the surrounding rock system, stress and energy criteria for coalburst occurrence are derived. Taking the bursting energy index and uniaxial compressive strength as variables, the average errors between the two criteria are 3.98% and 1.21%, respectively. A case from the Ordos mining area and data from 127 coalburst-prone mines in China are then used to clarify the differences in coalburst mechanisms between solid coal roadways and gob-side roadways. The results show that the critical stress of gob-side roadways is significantly lower than that of solid coal roadways. The proposed criteria provide a theoretical basis for coalburst-risk assessment and coalburst-prevention design in gob-side roadways.