Annular Grout Volume for Cased Bore / Pipe-in-Casing
The grout volume in the ring between a bored casing and the carrier pipe.
Example
You enter
- Bore / casing inside diameter (in) 24
- Carrier pipe outside diameter (in) 16
- Run length (ft) 100
- Pumping / overcut waste (%) 5
You get
- Annular area 251.3 in^2
- Neat annulus volume 174.5 ft^3
- Grout (cy) 6.7874
Details, formula, and sources
Annular area = pi/4 (bore^2 - carrier^2), volume = area x length grossed for waste. A 24 in bore around a 16 in carrier over 100 ft is a 6.46 cy ring (1,306 gal), ~6.79 cy ordered. The field always overruns the neat annulus.
annular_area_in2 = (pi/4) x (bore_dia_in^2 - carrier_od_in^2); neat_ft3 = annular_area_in2 / 144 x length_ft; grout_cy = neat_ft3 / 27 x (1 + waste_pct/100); grout_gal = neat_ft3 x 7.48052 x (1 + waste_pct/100).
Annular-area identity by name (ring between two concentric circles); first-principles volume arithmetic.
The annular-area identity is public geometry; the 7.48052 gal/ft^3 constant is exact.
Estimate. AHJ and licensed professional govern.
Field names used by the API: bore_dia_in, carrier_od_in, length_ft, waste_pct, annular_area_in2, neat_ft3, grout_cy
- Waste factor 5% pumping / overcut default; the field always overruns the neat annulusboring / grouting practice
- Volume constants 144 in^2/ft^2, 27 ft^3/cy, 7.48052 gal/ft^3 (exact)physical fact