Grouting Technique for Gob-Side Entry Retaining in Deep Mines

Table 1

Mechanical properties of coal specimen before and after grouting.

No.	Water-cement ratio	Intact specimen UCS (MPa)	Intact specimen residual strength (MPa)	Grouting geocomposite specimen UCS (MPa)	Consolidation coefficient	Recovery coefficient (%)
1	1.0	19.50	2.84	8.19	2.88	41.98
2		24.63	2.50	7.52	3.01	30.54
3		16.01	2.04	5.36	2.63	33.48
4	0.8	11.45	2.73	5.33	1.95	46.54
5		26.74	-	0.54	-	2.01
6		22.92	3.32	10.49	3.16	45.76
7	0.7	19.19	5.37	8.83	1.64	46.02
8		16.51	5.80	4.65	0.80	28.19
9		8.30	2.98	3.83	1.29	46.14