Question

Embankment fill is to be compacted at a density of $18kN/m^3$. The soil of the borrow area is at a density of $15kN/m^3$.What is the estimated number of trips of $6/m^3$ capacity truck for hauling the soil required for compacting $100/m^3$ fill of the embankment? (Assume that the soil in the borrow area and that in the embankment are at the same moisture content)

• A. 14
• B. 18
• C. 20
• D. 23

Answer 1

The correct option is C 20

(c)
In problems of fill and borrow pit, the volume of soil solids shall be equated.
$V_S=\frac{V}{1+e}=\frac{V_{\gamma }}{G(1+W){\gamma }_w}$

As the moisture content of borrow area and that of embankment are same.

$V_1{\gamma }_1=V_2{\gamma }_2$

For 100m fill at embankment, the volume required from borrow pit

$V_2=\frac{100\times 18}{15}=120m^3$

$Numberoftripsoftruck=\frac{120}{6}=20$