A Study on the Generation Mechanism and Development Process of Piping Based on the Theory of Muddy Water Seepage

Table 1

Physical and mechanical parameters of materials [23].

Materials	Relative density	Initial porosity	Initial permeability coefficient; (cm/s)	Critical hydraulic gradient
White fine sand	2.68	0.48		0.87
Sand gravel	2.65	0.21		1.30