为加快“海洋强国战略”的实施、落实习总书记提出的“一带一路”的战略构想，我国正在南海实施吹填造岛和岛礁工程建设。通常陆源吹填土具有低承载力和高压缩性的特点，而南海吹填珊瑚礁砂地基在水力吹填过程中具有自密实作用，形成陆域后地基密实度高、承载力高、压缩性低、固结稳定快，可直接作为低层建筑物的地基。本项目通过吹填岛礁现场地质调查、取样、原位测试、室内实验、模型试验与理论分析相结合的研究方法，研究南海吹填礁砂的沉积规律、级配、颗粒形状、地基密实度和力学特性；采用自行设计的水力密实模拟试验系统模拟珊瑚礁砂水力吹填密实的成因机制；通过细观结构分析及力学试验，揭示吹填礁砂颗粒咬合嵌固自密实机理，分析咬合力对强度和变形的影响，建立考虑颗粒咬合力的钙质土抗剪强度理论和土压力计算公式；提出吹填优化措施和地基稳定性评价方法。本项目的研究具有理论创新意义，研究结果将为岛礁吹填施工、地基处理和工程设计提供科学指导。

In order to implement the maritime power strategy and the strategic concept of “One Zone and One Road” proposed by Chairman Xi, reclamation islands and reef constructions in South China Sea are underway. Generally, terrigenous dredger fill has the characteristics such as low bearing capacity and high compressibility. However, calcareous dredging soils are naturally dense during dredging. The soils can be used as low-rise buildings foundations due to the merits of high compactness, high bearing capacity, low compressibility and fast consolidation. Sedimentary pattern, gradation, range of particle sizes, grain shape, compactness and mechanical properties of calcareous dredging soils will be studied through integrated research methods consisting of field geological investigations, sampling, in situ testing, physical and mechanical experiments, laboratory model tests and theoretical analysis. The compacting effect of hydraulic dredging is simulated by self-designed hydraulic compaction simulation system. Microstructure analysis and mechanical experiments will be carried out aiming to reveal the occlusion mechanism of dredging calcareous soil particles and the effects on soil strength and deformation. Shear strength theory and soil pressure calculation method will be established considering the particle occlusion. Dredging measures optimization and estimation of ground stability will be proposed. This study is theoretically innovative and the results will provide scientific guidance for reclamation constructions, ground treatment and engineering design on coral reefs.