Question

The critical hydraulic gradient ic in terms of specific gravity G and voids ratio e is given by ______

(a) Ge

(b) G/e

(c) \(\frac{G-1}{1+e}\)

(d) \(\frac{G+1}{1-e}\)

I had been asked this question in examination.

Asked question is from Seepage Pressure and Upward Flow in division Seepage Analysis of Geotechnical Engineering I

Answer 1

The correct choice is (c) \(\frac{G-1}{1+e}\)

For explanation I would say: The critical hydraulic gradient ic is given by,

\(i_c= \frac{γ’}{γ_w}\)

\(γ’=\frac{G-1}{1+e} γ_w \)

∴ \(i_c=\frac{G-1}{1+e}.\)