<p>Helical piles were installed in dry sandy soil with fixed geometric parameters including helix spacing, embedment depth, number of helix plates, and helix plate diameter. Cylindrical grout was applied around the piles at varying diameters and depths below the ground surface. Fifty-one model tests were conducted on different pile configurations. The examined parameters included the grout diameter to pile diameter ratio (1.5, 2, 2.5, and 3), the grout length to pile length ratio (0.2, 0.3, 0.4, and 0.5), and the relative density of the surrounding sand (78%, 47%, and 29%). The test results indicated that at an embedment ratio of 0.5 for grout length to pile length and 3 for grout diameter to pile diameter, grouted helical piles showed an increase in ultimate uplift capacity by factors of 1.15, 1.21, and 1.32 compared to ungrouted piles, corresponding to sand relative densities of 78%, 47%, and 29%, respectively. These factors illustrated that the grouting benefit was most pronounced in looser sand. Grouting increased uplift capacity with higher grout to pile diameter ratio and grout to pile length ratio due to grout-soil friction. The grouted section and steel shaft acted together as a single pile with an effectively larger diameter.</p>