Compression Index

The Compression Index 1 ($//<![CDATA[ \begin{array}{l}C_c\end{array} //]]>$) in Compression_Index_1 is defined as:

$$//<![CDATA[ \begin{array}{l}\displaystyle C_c=\frac{2.3(1+e)\cdot\sigma'_{v0}}{M}\end{array} //]]>$$

CPT in Geotechnical Practice p 71

Where:
     $//<![CDATA[ \begin{array}{l}e\end{array} //]]>$ is the Void Ratio, and is stored in the Void_Ratio field.
     $//<![CDATA[ \begin{array}{l}M\end{array} //]]>$ is the constrained modulus, and is taken from the Constrained_Modulus_1 field.

The constant and e are stored on CPT_POINT_CORRELATION_PARAMETERS and CPT_PROJECT_CORRELATION_PARAMETERS tables.