Abstract: Base on previous research on soil arching effect between adjacent piles, the concept of load transfer ratio of soil arching was proposed, and an analysis model was established. Through centrifuge model test, the Ito's calculation method of lateral pressure on pile was proved to be applicable to deep foundation supported with sparse row piles. Based on this approach, the influence factor of the load transfer ratio of soil arching was comprehensively analyzed with an assumed case of sparse row piles. Results show that the earth pressure passing to the pile by soil arching can account for over 60% of the total pressure on the pile. Therefore, soil arching effect between adjacent piles in sparse row pile retaining structure can not be ignored. The load transfer ratio of soil arching approximately exponentially decreases with the increase in pile space. When the pile space is constant the load transfer ratio decreases with the increase in pile diameter. In addition, if parameters are unchanged, the load transfer ratio exponentially increases with the cohesion and internal friction angle of the soil.

Key words: sparse row piles, soil arching effect, load transfer ratio of soil arching, centrifuge model test