This study investigates the effect of pile spacing on the bearing capacity of group piles and proposes optimal spacing to enhance design efficiency. The theoretical analysis, based on Terzaghi's failure mode and the arching effect, evaluates the influence of spacing adjustments on bearing capacity improvement. Laboratory model tests were conducted to experimentally validate the theoretical findings, comparing pile capacities under various spacing conditions. The results reveal that arching effects become significant when the spacing ratio exceeds 1.7, leading to a substantial increase in bearing capacity. This research proposes an optimal spacing range to supplement current design standards and provides foundational data for efficient pile design.
