Table 2 Soil properties of volcanic soil and Toyoura sand.

Dry density, ρ_d (kg/m³)

1695

1580

Porosity, n

0.36

0.40

Saturated hydraulic conductivity, k_s (m/s)

1.12 × 10⁻⁵

1.04 × 10⁻⁴

Residual volumetric water content, θ_r (m³/m³)

0.035

0.04

Saturated volumetric water content, θ_s (m³/m³)

0.36

0.04

Effective cohesion, c’ (kPa)

0, 1, 2, 3, 4

1.5, 2, 2.5, 3

Effective angle of internal friction, ϕ’ (°)

33, 34, 35, 36, 37, 40

35, 36, 37, 38