In terms of soil quality, what does a higher Group Index (GI) number imply?

A higher Group Index (GI) number indicates that the soil is more problematic. The Group Index is a classification system used primarily in highway engineering to assess the quality of soil for road construction. It evaluates the soil's potential performance based on various factors, including plasticity, moisture content, and grain size distribution.

When the GI number increases, it generally correlates with poorer soil conditions, suggesting that the soil possesses traits such as high plasticity, increased moisture retention, or a lack of cohesion, which can lead to issues like excessive settlement, instability, or unsuitability for supporting structures. Therefore, a higher GI number signals that the soil may require additional considerations during engineering design and construction, such as enhanced drainage measures or the need for stabilization techniques, reflecting its problematic nature.