Example Problems

Example Problem 1: A laboratory compaction test yields a maximum dry unit weight of $18.5 \, kN/m^3$ at an optimum moisture content of $12\%$. A field density test results in a moist unit weight of $19.0 \, kN/m^3$ and a water content of $10\%$. The specification requires $95\%$ relative compaction. Is the specification met?

Example Problem 2: A standard Proctor compaction test on a soil sample yielded a maximum dry unit weight of $18.5 \, kN/m^3$ and an optimum moisture content of $14\%$. The specific gravity of the soil solids is $2.68$. Calculate the void ratio and degree of saturation at the optimum moisture content.

Example Problem 3: A field density test using the sand cone method was performed on a compacted earth fill. The dry weight of the soil excavated from the hole was $15.2 \, N$. The volume of the hole, determined from the sand cone, was $0.00085 \, m^3$. If the laboratory standard Proctor test for this soil gave a maximum dry unit weight of $18.8 \, kN/m^3$, calculate the relative compaction in the field.