Abstract: Inclined pile support has notably extended the applicable depth of unsupported retaining structures, boasting advantages such as cost-effectiveness, ease of construction, environmental friendliness, and precise deformation control. However, current researches focus on single row inclined piles, while research on the testing, theory, and application of inclined double-row pile support remains limited. We conducted field experiments to assess excavation supported by double-row piles with the front row inclined. Additionally, employing the finite element method, we investigated the underlying working mechanisms from three aspects: the front-row inclined double-row piles, the connecting beam on top of piles, and the soil interaction among piles. We further examined the impact of pile length and row spacing on the deformation characteristics of inclined double-row piles. Our findings indicate a marked enhancement in the supportive capabilities of front-row inclined double-row pile compared to traditional vertical double-row piles. The front-row inclined double-row piles primarily serve as diagonal bracing, while the beams connect the piles and the crown beam into a spatially rigid frame. Soil between the piles enhances pile-soil friction, effectively mitigating deformation in inclined double-row piles.

Key words: foundation pit excavation, front-row inclined double row piles, field experiment, working mechanism, soft soil area