The Movement Characteristics of Coal Granular Body in Excavating Rescue Channel in the Collapsed Body

Figure 14

The relationship between the natural repose angle and the slip surface. (a) The 46° natural repose angle. (b) The 36° natural repose angle. (c) The 26° natural repose angle. (d) The 16° natural repose angle.

(a)

(b)

(c)

(d)