Analysis of load transfer and deformation behavior in granular compaction piles

The sand compaction pile (SCP) method has been widely utilized for soft ground improvement. However, environmental and economic concerns arising from sand depletion have prompted exploration into alternative solutions. The granular compaction pile (GCP) method, utilizing materials such as crushed stone or recycled concrete, has emerged as a viable substitute. Despite extensive research on GCPs, a comprehensive understanding of how bulging failure influences their efficiency remains limited. This study investigates the load transfer mechanisms and deformation behavior of both tapered and uniform GCPs through static pile load tests and subsequent numerical analyses. The results indicate that applied loads on GCPs are primarily distributed via shaft friction within a depth of approximately 1.0 times the pile diameter. Maximum lateral expansion displacement occurs at a depth of approximately 1.5 times the pile diameter or more, varying with soil stiffness. Furthermore, increased stiffness of the soil strata leads to an expanded stress transfer range, causing ground deformation that extends beyond the surface layer to affect deeper soil layers. These findings enhance the understanding of GCP performance and underscore their potential for sustainable ground improvement applications.