318/3338–12FE Reference Handbook 10.4 · Construction · Earthwork

Handbook formula

Swell and Shrinkage

Bank cubic yards (BCY) are in-situ. Loose (LCY) after digging is larger (swell). Compacted (CCY) fill is often smaller than bank (shrink). Never add swell and shrink without converting through BCY.

Bank cubic yards
Loose cubic yards
Compacted cubic yards

Step-by-step solved example

Excavate 1000 BCY, swell = 25%, shrink to fill = 10%. LCY hauled? CCY of fill from this material?

BCYCCYL
Bank → loose (swell) in trucks → compacted in the fill section.
  1. 1. Loose

    LCY = 1000×1.25 = 1250 LCY.

  2. 2. Compacted

    CCY = 1000×(1−0.10) = 900 CCY.

Answer: 1250 LCY hauled, 900 CCY in place

10 practice questions

0/10 correct

1.Swell of 20% means 1 BCY becomes

2.Shrink 15%: 1 BCY →

3.Truck capacity is usually quoted in

4.To fill 800 CCY with 10% shrink, BCY needed =

5.Load factor (sometimes) is BCY/LCY =

6.Rock often has

7.Mixing 30% swell with 10% shrink as 40% is

8.1000 LCY with 25% swell came from

9.Unit weight is highest typically in

10.Pay quantity for excavation is often