Study on Deformation and Fracture Evolution of Underground Reservoir Coal Pillar Dam under Different Mining Conditions

Table 3

Orthogonal experiment range analysis Tab. (plastic zone development height).

Factor	Length of working face/m	Width of coal pillar/m	Mining height/m	Water pressure/MPa
Average results of the first level	12.38	14.75	14.38	15.25
Average results of the second level	15.00	15.00	14.63	15.50
Average results of the third level	15.63	15.63	15.25	15.88
Average results of the fourth level	19.50	17.13	18.25	16.13
Range	7.13	2.38	3.88	0.88