Model pile load testing was conducted in a controlled environment to study how piles behave under vertical loads in sand. The researchers tested individual piles and pile groups in sand samples of different densities. They looked at both non-displacement and driven piles to see how the way the piles were installed affected their response to loads. The researchers developed a method to predict how a pile group will respond based on the behavior of a single pile, and found that their predictions matched the actual measurements well. They also discussed how factors like pile group configuration, spacing, soil density, and installation method can influence pile behavior.