SSC JE Civil Engineering 23 Mar 2021 Shift 1 Paper

Concept: Dry Unit Weight $(\gamma_{d}):$ It is a measure of the weight of solid particles per unit volume. $\gamma_{d}=\frac{W_{s}}{V}$ Where $W_{s}=$ weight of solid particles, $V=$ Volume of solid particles Now the relationship between the specific gravity of solid particles, void ratio, and dry unit weight $\gamma_{d}=\frac{G \gamma_w}{1+e}$ where G = specific gravity of solid particles, e = void ratio Calculation: GivenData: The mass of a chunk of moist soil = 20 kg The dry density of soil $(\gamma_{d})=1500 \mathrm{kg/m}^{3}$ Specific gravity $(G)=2.50$ The density of water $(\gamma_{w})=1000 \mathrm{kg/m}^{3}$ Using the relationship between the specific gravity of solid particles, void ratio, and dry unit weight $\gamma_{d}=\frac{G \gamma_w}{1+e}$ $1500=\frac{2.50 \times 1000}{1+e}$ $(1+e)=\frac{2.50 \times 1000}{1500}$ e = 0.6667 The void ratio is 66.67%