Long-Term Bearing Deformation Characteristics of Caved Gangue in Gob under Different Moisture Conditions

Table 2

Parameters of caved gangue specimens during different testing stage.

Moisture condition	Testing stage	Deformation			Strain			Residual bulking factor
		Initial value (mm)	Final value (mm)	D-value (mm)	Accumulated strain/10^−3	Fitting formula of strain-time	R-square	Initial value	Final value
Dry	20–100 kN load	0	20.82	20.82	31.8	—	—	1.901	1.840
	100 kN constant load	20.82	23.01	2.19	35.1		0.982	1.840	1.834
	100–200 kN load	23.01	38.38	15.37	58.6	—	—	1.834	1.789
	200 kN constant load	38.38	42.23	3.85	64.5		0.970	1.789	1.778
	200–300 kN load	42.23	54.47	12.24	83.2	—	—	1.778	1.743
	300 kN constant load	54.47	59.67	5.20	91.1		0.973	1.743	1.727
	300–400 kN load	59.67	68.88	9.21	105.2	—	—	1.727	1.701
	400 kN constant load	68.88	74.07	5.19	113.1		0.941	1.701	1.686
Water Saturated	20–100 kN load	0	21.27	21.27	32.5	—	—	1.901	1.839
	100 kN constant load	21.27	25.30	4.03	38.6		0.996	1.839	1.827
	100–200 kN load	25.30	45.10	19.80	68.9	—	—	1.827	1.770
	200 kN constant load	45.10	53.19	8.09	81.2		0.995	1.770	1.746
	200–300 kN load	53.19	64.26	11.07	98.1	—	—	1.746	1.714
	300 kN constant load	64.26	72.61	8.35	110.9		0.995	1.714	1.690
	300–400 kN load	72.61	81.75	9.14	124.8	—	—	1.690	1.663
	400 kN constant load	81.75	91.00	9.25	138.9		0.994	1.663	1.637

Notes: ε is the accumulated strain of caved gangue specimen, ×10⁻³, t is the hold time in each constant load stage, min.