<p>The porous and brittle nature of coral gravel-sand mixtures can lead to engineering challenges, such as inadequate bearing capacity. To accurately simulate the bearing behavior of field foundations in geotechnical model tests, it is crucial to prepare foundation samples made from these mixtures. This study aimed to reconstruct coral gravel-sand mixtures samples using the sand pluviation method. The effects of drop height, flow mass rate, nozzle gap width, and moving path on both the average relative density and spatial uniformity of the coral gravel-sand mixtures samples were investigated. Three types of coral gravel-sand mixtures were designed based on the particle gradation during hydraulic reclamation: the gradation near the nozzle (GNN), the gradation away from the nozzle (GAN), and the well-designed gradation (WDG). The results indicate that the relative density increases linearly with drop height, decreases with higher flow mass rate and nozzle gap width, and is also influenced by the moving path. Among the three particle gradations, WDG has the highest average relative density, followed by GAN and GNN. For the WDG and GNN mixtures, as the flow mass rate and drop height increase, the relative density fluctuates more significantly around the mean line with variations in spatial position. The nozzle gap width has a little effect on spatial uniformity of coral gravel-sand mixtures. The spatial uniformity is better with the moving path of “W-type / L-type at long side” compared to the moving path of “W-type / L-type at short side”.</p>