Liquefaction Assessment

Assess liquefaction potential using FL method based on SPT N-value, groundwater level, and seismic intensity — free geotechnical tool

FL = R / L

R: Cyclic Resistance Ratio (from N-value & fines content)

L = 0.65 · (amax/g) · (σv/σv') · rd / MSF

FL < 1.0: Liquefaction Likely

Earthquake Parameters

Groundwater Level (m)

Earthquake Magnitude M

Max Acceleration (m/s²)

Soil Layers

Layer 1

SandSilt

Depth (m)

Thickness (m)

N-value

Fines Fc (%)

D50 (mm)

Layer 2

SandSilt

Depth (m)

Thickness (m)

N-value

Fines Fc (%)

D50 (mm)

Layer 3

SandSilt

Depth (m)

Thickness (m)

N-value

Fines Fc (%)

D50 (mm)

Layer 4

SandSilt

Depth (m)

Thickness (m)

N-value

Fines Fc (%)

D50 (mm)

Layer 5

SandSilt

Depth (m)

Thickness (m)

N-value

Fines Fc (%)

D50 (mm)

Assessment Results

Depth (m)	N-value	Soil	R	L	FL	Judgment
2.5	8	Sand	0.234	0.122	1.910	Safe
4.0	5	Sand	0.171	0.148	1.155	Caution
6.5	12	Sand	0.225	0.170	1.329	Caution
9.0	20	Silt	0.294	0.180	1.639	Safe
12.0	30	Sand	0.312	0.174	1.798	Safe

FL Distribution

2.5m

1.91

4.0m

1.16

6.5m

1.33

9.0m

1.64

12.0m

1.80

FL = 1.0