Combining the principle of the
“spherical shell losing stability” theory with the actual conditions of coal mine, every cause
which brings about delay outburst has been analysed.According to the analysis, the simulated
tests of delay outburst are carried out. The results show that coal and gas outburst is caused by
outburst coal when it is uncovered abruptly, and the reason of delay is that there is a creep
break occurring in the barrier layer or a cavi...