Combination response characteristics of gas seepage velocity-temperature under triaxial loading

Seepage velocity and temperature reflect the changes in the structure and energy of coal and can be used as early warning signals of coal and gas outburst. In this paper,the briquette was taken as the research object,and the self-developed test system was used to determine the joint response of seepage velocity and temperature under triaxial loading. The loading rate effect on gas seepage velocity and temperature was studied,and the relationship between gas seepage velocity and temperature and coal failure was established. The results show that:① During loading process, gas seepage velocity decreases first and then increases,and it changes suddenly at the peak of stress. With loading rate increases,the Vmin decreases first and then increases,while ( Vmax -Vmin ) increases first and then decreases. ② With stress increases,gas temperature increases linearly,and the (Tmax -Tmin )decreases. ③ When the loading rate is low,the seepage velocity appears “quiet period” at 80% of coal rupture. When the loading rate is high,the seepage tempera- ture fluctuates many times before rupture and there is a longer “ quiet period”. Those can be used as effective early warning information to highlight the coal rupture.