The abrupt change area of coal seam dip is one of the complex geological conditions that significantly increase the risk of coal and gas outburst during deep mining. Using a mine in Pingdingshan

Henan Province

as the research subject

we conducted experimental research to simulate coal and gas outburst under various inclination mutation conditions. An interface with a dip mutation was established

positioning raw coal on the upper side and type coal on the lower side to emulate primary and tectonic coal seams

respectively. The initial angle( ) of abrupt change in coal seam dip

the abrupt change angle( )

the critical value of the abrupt change angle( )

and the gas concentration coefficient( ) in the abrupt change area of coal seam dip were defined. The above parameters were used to analyze the effect of abrupt change in coal seam dip on the intensity of coal and gas outburst. The unit outburst intensity( ) was introduced to characterize the strength of coal and gas outburst during the test. Acoustic emission technology was employed to monitor the energy evolution pattern during coal and gas outburst

while temperature changes in each area were recorded using sensors embedded in the sample. The findings of the study indicate that: (1) The abrupt change area of coal seam dip significantly impacts on both the critical gas pressure and the unit outburst intensity during coal and gas outburst. There exists a critical value() of the abrupt change angle in coal seam within the range of 10º< ≤20º

10º≤ ≤20º. When both and  exceed or are equal to   

a low-index coal and gas outburst becomes more likely to occur. When or is fixed

the unit outburst intensity in the abrupt change area of coal seam dip increases as the gas concentration coefficient( I) increases. (2) A negative correlation exists between and both the peak and cumulative AE energy. A similar negative correlation exists between and both the peak and cumulative AE energy. As both and increase

the energy required for the coal body to reach rupture and destabilization progressively diminishes. Under identical geostress conditions

this phenomenon facilitates coal and gas outburst even at lower gas pressures. (3) Notable temperature variations occur within the coal body during the incubation and excitation phases of coal and gas outbursts. Temperature changes in the abrupt change area of coal seam dip are significantly higher than in other zones. Temperature fluctuations in the proximal region of the outburst vent show greater instability than in other regions.