A Study on the Seepage Flow Characteristics and Disaster-Causing Mechanism of Collapse Column

Table 2

Maximum strength and permeability coefficient of each sample.

	Collapse column-upper	Collapse column-middle	Collapse column-lower	Fissure zone-sandstone	Fissure zone-mudstone	Intact floor-sandstone	Intact floor-mudstone
Maximum axial pressure	48.01	52.01	48.01	69.63	28.81	89.63	48.01
Maximum permeability coefficient	0.95	0.84	0.77	262.39	0.47	27.9	4.9