Numerical Simulation of Deformation and Failure of Drainage Boat Pond Caused by Underground Coal Mining-Induced Subsidence

Table 1

Damage grade of brick-concrete structures [46].

Damage level	Horizontal distortion (mm/m)	Curvature (10^-3/m)	Inclination (mm/m)	Damage level
I	≤2.0	≤0.2	≤3.0	Minor damage
II	≤4.0	≤0.4	≤6.0	Mild damage
III	≤6.0	≤0.6	≤10.0	Moderate damage
IV	>6.0	>0.6	>10.0	Badly damaged