Effect of Cyclic Loading and Unloading on the Deformation and Damage Properties of Sandstone from Beizao, a Coal Mine underneath the Bohai Sea in China

Figure 8

Damage parameters of sandstone with different unloading stress levels: (a) absolute damage parameter of UC-C-1; (b) accumulated damage parameter of UC-C-1; (c) absolute damage parameters of UC-C-2; (d) accumulated damage parameters of UC-C-2.

(a)

(b)

(c)

(d)