Abstract:

The interaction mechanism of piles and slope soil is one of the important factors for the design of anti-sliding piles. On the basis of stress condition of the passive piles subjected to lateral force, the stress expression of arbitrary point of the soil behind the piles is derived from the basic theory of soil mechanics and elastic mechanics. Accordingly, the mechanical model of soil arch is created; and distribution of soil stress isolines is given. The shape of soil arch is found to be hyperbolic, shoulder expansion arch, saddle and domal which are distributed in different zones behind the pile groups. In addition, the mechanism of arching effect is completely interpreted; the relationship between pile spacing, pile width, distance behind piles and varying effect of soil arch are discussed in detail. Moreover, some factors influencing soil arching effect, such as inner friction angle and cohesion, are discussed as well. Furthermore, with regard to the problem of maximum pile spacing, in view of the stress condition of limiting equilibrium of soil at the arching crown, the control equation of maximum pile spacing is built based on the Mohr-Coulomb theory of soil shearing strength. Finally, a practical case of slope prevention engineering is studied for the design of pile spacing. This paper will play a great role for the realization of pile-slope interaction and contribute a lot to the theory of design of anti-sliding piles in the field of slope engineering.

Key words: slope, interaction of piles and slope soil, soil arch, mechanical model, pile spacing