Question

The relative compaction Rc is related to the void ratio of soil by _______

(a) \(\frac{(1+e)}{(1+e_{max})}\)

(b) \(\frac{(1+e)}{(1+e_{min})}\)

(c) \(\frac{(1+e_{min})}{(1+e)}\)

(d) \(\frac{(1+e_{max})}{(1+e_{min})}\)

I got this question in an interview for job.

I need to ask this question from Density Index and Relative Compaction in division Preliminary Definitions and Relationships of Geotechnical Engineering I

Answer 1

Correct choice is (c) \(\frac{(1+e_{min})}{(1+e)}\)

Easy explanation: The relative compaction is given by,

\(R_c = \frac{γ_d}{γ_{d,max}}\)

Since γd=γs(1+emin)

γd,max=γs(1+e)

∴ \(R_c= \frac{γ_d}{γ_{d,max}}= \frac{γ_s(1+e_{min})}{γ_s(1+e)} \)

\(R_c= \frac{(1+e_{min})}{(1+e)}. \)