Civil Engineering Tools
BeamTrussMohr's CircleUnit ConversionsCentroidDeflectionBucklingConcreteRebarFE Prep

Square Footing Size from Soil Bearing

Easyfootingbearing-areaservice-load
A square footing carries a total concentric service load of 800 kN, including the weights of the footing and overburden. The gross allowable soil bearing pressure is 200 kPa. Assume uniform pressure and no moment. What is the minimum theoretical side length B of the square footing?
  1. A4.00 m
  2. B2.00 m
  3. C2.37 m
  4. D2.14 m
Show solution

Answer: B. 2.00 m

Equation: A ≥ Pservice/qallow, B = √A. Substitution: A = 800/200 = 4.00 m²; B = √4.00 = 2.00 m (pressure 800/4 = 200 kPa exactly). Wrong: 4.00 m reports the area as if it were the side length; 2.37 m uses a factored load (1.4 × 800 = 1,120 kN) against an allowable pressure; 2.14 m adds an extra 15% for footing weight that is already included in the 800 kN.
m m
Practice this deckUntimed, one problem at a time, with your progress saved.

Related problems

Keep studying