Application of Fine Sand in Coastal Areas As Subgrade Filling

It is of economic and social benefit to use the fine sand in coastal areas as subgrade filling, which can overcome the lack of construction materials in these areas. However, the engineering properties of fine sand are different from the ordinary filling materials due to the bad gradation and looseness of structure. In this paper, a series of laboratory tests - including the sieve analysis, compaction characteristic, California bearing ratio (CBR) and modulus - was performed to assess the feasibility of filling with typical fine sands in Hainan and Shanghai. Then, the in-situ tests on construction method and quality were carried out. It is shown that, when fine sands are confined and covered by fine grain soils, sand-filling subgrade can provide sufficient stiffness and stability.