Expansion Index Calculator

Formula

The formula to calculate the expansion index is:

\[ EI = \frac{V_f - V_i}{V_i} \]

Where:

\( EI \) is the expansion index
\( V_f \) is the final volume (m³)
\( V_i \) is the initial volume (m³)

What is an Expansion Index?

An Expansion Index is a measure used in geotechnical engineering to determine the potential of soil to expand or shrink due to changes in moisture content. This is particularly important in construction and civil engineering as it helps in understanding how the soil might behave under different weather conditions or when water is introduced, which can affect the stability of structures built on it. The index is usually determined through laboratory tests on soil samples.

Example Calculation

Let's assume the following values:

Initial Volume (V_i) = 1.0 m³
Final Volume (V_f) = 1.2 m³

Using the formula to calculate the expansion index:

\[ EI = \frac{1.2 - 1.0}{1.0} = 0.2 \]

The expansion index is 0.2.