Question

The in situ moisture content of a soil is 18% and the moist (total) unit weight is 105 pcf. The soil is to be excavated and transported to a construction site for use in a compacted fill. If the specifications call for for the soil to be compacted at a minimum dry unit weight of 103 pcf at the same moisture content of 18%, how many cubic yards of soil of the excavation site are required for each cubic yard of compacted fill? Assume a soil specific gravity of 2.7.

Answer 1

Answer: Volume= 1.16 yd³

Explanation:

We are given the in-situ moisture content= 18% and moist unit weight= 105 pcf

First we find out the dry unit weight

Dry unit weight= Moist unit weight / (1+ moisture content)

Dry unit weight= $\frac{105}{1.18}$

Dry unit weight= 88.983 pcf

Now, to find the volume ( in terms of each cubic yard i.e 1 yd³ we have

Volume = Dry unit weight compacted / Dry unit weight (in-situ) * 1 yd³

Volume= $\frac{103.5}{88.983} * 1$

Volume= 1.16 yd³