Question

The compression index is given by _________

(a) \(C_c=\frac{e_0-e}{log_{10} \frac{σ’}{σ’_0}}\)

(b) \(C_c=\frac{e}{log_{10} \frac{σ’}{σ’_0}}\)

(c) \(C_c=\frac{e_0-e}{\frac{σ’}{σ’_0}}\)

(d) \(C_c=\frac{e_0}{log_{10} \frac{σ’}{σ’_0}}\)

The question was posed to me in examination.

This key question is from Consolidation Process in section One Dimensional Consolidation of Geotechnical Engineering I

Answer 1

The correct choice is (a) \(C_c=\frac{e_0-e}{log_{10} \frac{σ’}{σ’_0}}\)

The explanation: The compression index is given by the expression,

 \(C_c=\frac{e_0-e}{log_{10} \frac{σ’}{σ’_0}}\) ,where e0= initial voids ratio corresponding to the initial pressure σ’0.

e=vids ratio at increased pressure  σ’

\(\)Cc=compression index.