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Embankment 1,00,000 m³ excavation

Short answer

Excavate 1,53,333 m³ of soil, with a moist weight of 1.84×10⁶ kN (dry weight 1.6×10⁶ kN).

An embankment of 1,00,000 m³ volume has to be constructed by compacting the soil brought from an excavation site. After compaction, the dry unit weight of the compacted soil (embankment) will be 16 kN/m³. Also, the bulk unit weight and water content of the soil at the excavation site are 12 kN/m³ and 15%, respectively. Find the volume and weight of soil to be excavated from the excavation site. Take specific gravity of soil solid as 2.70.

Given

Embankment: V=1,00,000V = 1{,}00{,}000 m³, γd=16\gamma_d = 16 kN/m³. Excavation site: γ=12\gamma = 12 kN/m³, w=15%w = 15\%, G=2.70G = 2.70.

Dry weight needed in the embankment

Ws=16×100 000=1.6×106 kNW_s = 16 \times 100\,000 = 1.6 \times 10^{6}\ \text{kN}

Dry unit weight at the excavation site

γd=γ1+w=121.15=10.435 kN/m3\gamma_d = \frac{\gamma}{1+w} = \frac{12}{1.15} = 10.435\ \text{kN/m}^3

Volume to be excavated

Vexc=Wsγd=1.6×10610.435=1.533×105 m3V_{exc} = \frac{W_s}{\gamma_d} = \frac{1.6 \times 10^6}{10.435} = 1.533 \times 10^{5}\ \text{m}^3

Weight of soil to be excavated (moist)

W=γ×Vexc=12×153 333=1.84×106 kNW = \gamma \times V_{exc} = 12 \times 153\,333 = 1.84 \times 10^{6}\ \text{kN}

(check: Ws(1+w)=1.6×106×1.15=1.84×106W_s(1+w) = 1.6 \times 10^6 \times 1.15 = 1.84 \times 10^6 kN)

The specific gravity is not needed for this answer; it would only be used to find void ratios.

Answer: volume ≈1,53,333\approx 1{,}53{,}333 m³; weight ≈1.84×106\approx 1.84 \times 10^{6} kN (dry weight 1.6×1061.6 \times 10^{6} kN).

✓ Answer checked by Claude Opus 5.5 (high effort)

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