Calculator to calculate loose soil thickness from desired compacted thickness

Loose Thickness & Void Ratio Calculator

Calculates required loose lift thickness prior to compaction and computes loose and compacted void ratios from specific gravity (G_s).

Compacted thickness (T_c)

mm cm m

Loose bulk density (ρ_l) in Mg/m³ Compacted bulk density (ρ_c) in Mg/m³ Specific gravity of solids (G_s)

Results

Loose thickness (T_l): —

Increase / bulking (Δ): —

Percentage increase: —

Loose void ratio (e_l): —

Compacted void ratio (e_c): —

Stepwise Calculation Output

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Example Theory & Worked Problem

Formulas Used:

• Loose Thickness: T_l = T_c × (ρ_c / ρ_l)
• Bulking Difference: Δ = T_l - T_c
• Percentage Increase: % = (Δ / T_c) × 100
• Void Ratio Formula: e = (G_s × ρ_w / ρ) - 1   (where ρ_w = 1.0 Mg/m³)

Solved Example Setup:

• Target Compacted Thickness (T_c) = 150 mm
• Loose Bulk Density (ρ_l) = 1.55 Mg/m³
• Compacted Bulk Density (ρ_c) = 1.85 Mg/m³
• Specific Gravity (G_s) = 2.70

Solution:

1. T_l = 150 × (1.85 / 1.55) = 179.03 mm
2. Δ = 179.03 - 150 = 29.03 mm
3. % Increase = (29.03 / 150) × 100 = 19.35 %
4. e_l = (2.70 × 1.0 / 1.55) - 1 = 0.742
5. e_c = (2.70 × 1.0 / 1.85) - 1 = 0.460