Question

The flow value is given by ______

(a) \(N_φ=cot^2 (45°+\frac{φ}{2})\)

(b) \(N_φ=cos^2 (45°+\frac{φ}{2})\)

(c) \(N_φ=tan^2 (45°+\frac{φ}{2})\)

(d) \(N_φ=sin^2 (45°+\frac{φ}{2})\)

The question was asked by my school principal while I was bunking the class.

My question is taken from Earth Pressure Introduction topic in division Failure Envelopes & Earth Pressure of Geotechnical Engineering II

Answer 1

Right option is (c) \(N_φ=tan^2 (45°+\frac{φ}{2})\)

The explanation is: The flow value is given by,

\(N_φ= tan^2 (45°+\frac{φ}{2}),\)

where, Nφ=flow value

φ=angle of internal friction.