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.

钙质砂经常用于填充岛礁。钙质砂的渗透性是决定钙质砂基础施工中固结时间和淡水储量的关键参数。孔结构特征是影响渗透率的关键因素。在这项研究中，X射线计算机断层扫描（CT）结合孔隙网络模型被用来研究不同粒径的钙质砂的孔隙特征和渗透性。结果表明，钙质砂样品中孔的数量和体积随粒径的增加而增加。孔体积分布不均匀，并且孔形状不会随着粒径而显着改变。钙质砂的渗透性随粒度增加而增加。孔隙数量和孔隙分布是决定不同粒径钙质砂渗透性的关键因素。当粒径大于1.45mm时，内部孔的存在对孔的总数和渗透性具有更大的影响。