Experimental study on permeability characteristics of calcareous soil

The artificial islands are covered by calcareous soil (CS) through hydraulic reclamation on coral reefs in the South China Sea. After construction of land reclamation, abundant rainwater infiltrates into the island and becomes groundwater. Therefore, the permeability of CS plays a critical role in the development of underground freshwater in islands. In this paper, a series of laboratory seepage experiments were conducted to study the permeability of CS considering different gradations and void ratios. Experimental results exhibit very good relationships between the coefficient of permeability and void ratio, uniformity coefficient, coefficient of curvature and grain size of CS. In addition, a mathematic model for calculating the coefficient of permeability of CS was developed considering all these factors. The model can be used to evaluate the permeability of coral reef foundations, and analyze the formation and evolution of groundwater in coral reefs and islands in the South China Sea.