Question

For purely cohesive soil, the bearing capacity is given by which of the following equation?

(a) qf = 5.7 c + σ̅

(b) qf = c + σ̅

(c) qf = 5.7 c

(d) All of the mentioned

This question was addressed to me during an interview for a job.

Asked question is from Terzaghi’s Analysis in portion Bearing Capacity of Geotechnical Engineering II

Answer 1

Right option is (a) qf = 5.7 c + σ̅

To explain: For purely cohesive soil the bearing capacity is

qf = c Nc + σ̅ Nq = 5.7 c + σ̅

Where σ̅ = γ D if the water table is below the base of the footing.