The in situ void ratio of a borrow pit soil is 0.72. The borrow pit soil is to be excavated and transported to fill a construction site where it will be compacted to a void ratio of 0.42. The construction project required 10000 m^3 of compacted soil fill Required Volume of soil that must be excavated from the borrow pit to provide the required volume of fill.
Answers
Given : void ratio of a borrow pit soil is 0.72.
The borrow pit soil is to be excavated and transported to fill a construction site where it will be compacted to a void ratio of 0.42
The construction project required 10000 m^3 of compacted soil
To Find : Volume of soil that must be excavated from the borrow pit to provide the required volume of fill.
Solution:
void Ratio = Void (air) Volume / Solid Volume
construction project required 10000 m³of compacted soil
a void ratio of 0.42
Void/ Solid = 0.42
=> Void = 0.42Solid
Total = Solid + 0.42Solid
=> Total = 1.42Solid
10000 m³ = 1.42Solid
=> Solid = 10000/1.42
borrow pit soil is 0.72.
Void / Solid = 0.72
=> Void = 0.72 * Solid
=> Void = 0.72 * 10000/1.42
Total = Solid + Void
= 10000/1.42 + 0.72 * 10000/1.42
= 10000 ( 1.72/1.42)
=12,112.68 m³
soil that must be excavated from the borrow pit =12,112.68 m³