(a)
(b)
(c)
(d)
(e)
Figure 2: Triaxial stress-time curves of coal samples and acoustic emission-time curves. (a) Initial isobaric pressure (RURLR of 0.6). (b) High initial unloading lateral stress (RURLR of 0.6). (c) High initial stress of loading lateral (RURLR of 0.6) (d) High initial stress of fixing lateral (RURLR of 0.8). (e) High RURLR (2.9).