A Method for Calculating the Earth Pressure Acting on a Retaining Wall Considering the Effect of an Adjacent Single Pile Composite Foundation

For an excavation project, the existence of adjacent composite foundations influences the earth pressure on the retaining wall, which will have a significant implication for the design and construction of the excavation project. In this paper, a simplified method is proposed to assess the influence of an adjacent single pile composite foundation in the calculation of earth pressures on a retaining wall, in which the pile-soil interaction within the composite foundation is considered. Comparison was made between the proposed method and the existing methods where the pile-soil interaction is ignored, which shows that the existing methods can overestimate or underestimate the earth pressure to a large extent. For the excavation project considered in this research, when the pile-excavation distance exceeds seven times the pile diameter, the influence of the composite foundation can be reasonably ignored.