Experimental Study of Slurry Flow in Mining-Induced Fractures during Longwall Overburden Grout Injection

Table 1

Model laying parameters.

Lithology	Thickness (cm)	Material	Ratio	Layers	Strength (kPa)
Isolation layer	1	Paraffin : hydraulic oil : talcum powder : river sand : straw powder	1 : 2 : 5.7 : 34.2 : 1	2	95
Soft rock layer	3	Sand : calcium carbonate : gypsum : water	3.5 : 3.5 : 1.5 : 1	3	70
Key strata	2	Sand : calcium carbonate : gypsum : water	3 : 3.5 : 1.5 : 1	2	78
Immediate roof	3	Sand : calcium carbonate : gypsum : water	3.5 : 3.5 : 1.5 : 1	3	70