The effect of sand relative density on the capacities of improved model pile foundation under combined loadings

Abstract

This article shows the investigation into how sand relative densities can affect the capacities of improved model pile foundations (PFs). In this study, an improved PF is defined as a PF with sheet piles surrounding the pile cap. Two series of 1 g physical modeling tests are reported in this article. The first series of model PFs with various sheet pile lengths was subjected to vertical load (V). In order to study the effect of soil relative density on the foundation capacities, a second series of tests using model PFs with specific sheet pile lengths were conducted on sand with different densities under three kinds of loadings. The three kinds of loadings were vertical load (V), combined vertical and horizontal loads (V–H), and combined vertical and moment loads (V–M). Three types of model PFs were used in this study, and their loads and settlements were measured via load cells and linearly variable differential transducers (LVDTs). The results have shown an effective tendency in that the vertical, horizontal, and moment capacities of PFs combined with sheet piles can withstand forces greater than those of PFs at different sand relative densities.