Experimental Study on Sand Inrush Hazard of Water-Sand Two-Phase Flow in Broken Rock Mass

Table 2

Relationships between porosity and axial pressure of broken rock mass with different size gradations.

Axial pressure (MPa)	Porosity ()
	5~8 mm	8~10 mm	10~12 mm	12~15 mm	15~20 mm
0.76	0.464	0.453	0.442	0.429	0.419
1.06	0.444	0.433	0.421	0.405	0.393
1.44	0.426	0.414	0.399	0.383	0.367
1.94	0.408	0.395	0.380	0.362	0.343
2.60	0.390	0.377	0.360	0.340	0.319
3.31	0.375	0.362	0.344	0.323	0.299