Advances in Civil Engineering / 2018 / Article / Tab 3

Research Article

A Study on the Seepage Flow Characteristics and Disaster-Causing Mechanism of Collapse Column

Table 3

Permeability gradation for rock and earth.

Grade of permeabilityStandardSoil type
Permeability coefficient K (m/s)Permeability q (Lu)

Mostly impermeableK < 10−8q < 0.1Clay
Slightly permeable10−8 ≤ K < 10−70.1 ≤ q < 1Clay-silt
Weakly permeable10−7 ≤ K < 10−61 ≤ q < 10Silt-fine sand
Moderately permeable10−6 ≤ K < 10−410 ≤ q < 100Sand-sand gravel
Strongly permeable10−4 ≤ K < 10−2q ≥ 100Sand gravel-gravel
Very strongly permeableK ≥ 10−2Boulder

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