Three-dimensional pore characteristics and permeability properties of calcareous sand with different particle sizes

Abstract

Calcareous sand is often used for island reef filling. The permeability of calcareous sand is a key parameter used to determine the consolidation time and the storage of fresh water during the construction of calcareous sand foundation. Pore structure characteristics are the key factors affecting permeability. In this study, X-ray computed tomography (CT) combined with pore network modeling were used to study the pore characteristics and permeability properties of calcareous sand with different particle sizes. The results show that the number and volume of pores in calcareous sand samples increase with increasing particle size. The pore volume distribution is uneven, and the pore shape does not change significantly with particle size. The permeability of calcareous sand increases with increasing particle size. The number of pores and the pore distribution are the key factors determining the permeability of calcareous sand with different particle sizes. When the particle size is larger than 1.45 mm, the presence of internal pores has a greater impact on the total number of pores and the permeability.