SEGJ Technical Conference

An idea of the interpretation of the relationship between permeability and fine fraction content for unconsolidated soil ground.

Abstract A permeability of unconsolidated soils are obtained by lab-test, pumping test and in-situ permeability test in single borehole, however, estimation method from representative grain diameter is accepted in practical cases. Creagers equation is one the most usual equation in these equations. It defines the permeability range of each soil by D20 diameter. We collected 1000 in-situ permeability test and grain size analysis data obtained at same borehole and same geological formations. The permeability data estimated from Creagers equation are larger than permeability obtained by in-situ permeability test for gravel formation, and smaller for silt formation. The difference between permeability from Creagers equation and in-situ test correlates with fine fraction content. We made a corrected Creagers equation using fine fraction content, and we proposed different equation to estimate permeability from fine fraction content.