What is a Borrow Pit?
A borrow pit is essentially a hole dug into the ground to extract materials like soil, gravel, or sand. These materials are then transported and used for construction projects at another location. Imagine it as a quarry, but typically smaller and for less substantial materials.
Common uses of materials from borrow pits are filling embankments for highways, dams, or land reclamation. Borrow pits are also used to create foundations for buildings or structures. Producing construction materials like concrete, bricks, or asphalt.What is Borrow Pit Soil?
Borrow pit soil is simply the type of soil extracted from a borrow pit. Its characteristics can vary widely depending on the geological location. It can range from sandy and gravelly to clayey and silty.
Borrow Pit Soil Calculation for Embankment
A soil in the borrow pit is at a dry density of 18 kN/ m³ with a moisture content of 12%. The soil is excavated from this pit and compacted in a embankment to a dry density of 19 kN/ m³ with a moisture content of 16%. Compute the quantity of soil to be excavated from the borrow pit and the amount of water to be added for 100 m³ of compacted soil in the embankment. Also you can use bellow calculator to evaluate your desired borrow pit soil to fill embankment.
Soil Calculation from Borrow Pit for Embankment
To solve this problem, we need to calculate two things:
The quantity of soil to be excavated from the borrow pit to achieve 100 m³ of compacted soil in the embankment.
The amount of water to be added to the soil for achieving the desired moisture content in the embankment.
Given Data
Dry density of soil in the borrow pit, 𝜌𝑑1=18 kN/m³Moisture content of soil in the borrow pit, 𝑤1=12%
Dry density of soil in the embankment, 𝜌𝑑2=19 kN/m³
Moisture content of soil in the embankment, 𝑤2=16%
Volume of compacted soil in the embankment, 𝑉2=100 m³
Step 1: Compute the Mass of Dry Soil in the Embankment
Mass of dry soil in embankment=ρd2×V2Mass of dry soil in embankment=19 kN/m³×100 m³
Mass of dry soil in embankment=1900 kN
Step 2: Compute the Volume of Soil to be Excavated from the Borrow Pit
We need to find the volume of soil in the borrow pit that provides 1900 kN of dry soil mass.
V1=ρd1/Mass of dry soil in embankment𝑉1=1900 kN/18 kN/m³
𝑉1=105.56 m³
First, calculate the initial and final masses of the soil including water content.
Initial Mass of Soil in the Borrow Pit (Including Water)
𝜌𝑏𝑢𝑙𝑘1=𝜌𝑑1×(1+𝑤1)
𝜌𝑏𝑢𝑙𝑘1=18 kN/m³×(1+0.12)
𝜌𝑏𝑢𝑙𝑘1=18 kN/m³×1.12
𝜌𝑏𝑢𝑙𝑘1=20.16 kN/m³
Initial mass of soil (including water)=𝜌𝑏𝑢𝑙𝑘1×𝑉1
Initial mass of soil (including water)=20.16 kN/m³×105.56 m³
Initial mass of soil (including water)=2128.09 kN
Final Mass of Soil in the Embankment (Including Water)
𝜌𝑏𝑢𝑙𝑘2=𝜌𝑑2×(1+𝑤2)
𝜌𝑏𝑢𝑙𝑘2=19 kN/m³×(1+0.16)
𝜌𝑏𝑢𝑙𝑘2=19 kN/m³×1.16
𝜌𝑏𝑢𝑙𝑘2=22.04 kN/m³
Final mass of soil (including water)=𝜌𝑏𝑢𝑙𝑘2×𝑉2
Final mass of soil (including water)=22.04 kN/m³×100 m³
Final mass of soil (including water)=2204 kN
Step 4: Compute the Amount of Water to be Added
Amount of water to be added=Final mass of soil (including water)−Initial mass of soil (including water)
Amount of water to be added=2204 kN−2128.09 kN
Amount of water to be added=75.91 kN
𝜌𝑏𝑢𝑙𝑘2=𝜌𝑑2×(1+𝑤2)
𝜌𝑏𝑢𝑙𝑘2=19 kN/m³×(1+0.16)
𝜌𝑏𝑢𝑙𝑘2=19 kN/m³×1.16
𝜌𝑏𝑢𝑙𝑘2=22.04 kN/m³
Final mass of soil (including water)=𝜌𝑏𝑢𝑙𝑘2×𝑉2
Final mass of soil (including water)=22.04 kN/m³×100 m³
Final mass of soil (including water)=2204 kN
Step 4: Compute the Amount of Water to be Added
Amount of water to be added=Final mass of soil (including water)−Initial mass of soil (including water)
Amount of water to be added=2204 kN−2128.09 kN
Amount of water to be added=75.91 kN
Summary of Results
Volume of soil to be excavated from the borrow pit: 105.56 m³
Amount of water to be added for 100 m³ of compacted soil in the embankment: 75.91 kN or 7.74 m³ (approx)
Soil Excavation and Water Addition Calculator
Volume of soil to be excavated from the borrow pit (V1): m³
Amount of water to be added: kN
