Abstract:

This paper presents an improved concentric arches model using the equivalence method for pile caps. The load transfer efficiency of geosynthetic-reinforced piled embankments with a triangular arrangement of piles is investigated. The pile cap with circular or square cross-sections is considered equivalent to a regular hexagon. The model is composed of three two-dimensional semicircular soil arches formed over the strip area between adjacent piles. A three-dimensional hemispherical soil arch is developed over the triangular area between three adjacent piles. Considering the geogrid deflects in a parabolic shape and the consolidation coefficient of the soil reaction, the frictional and adhesive tensions between the soil and the geogrid are obtained. The load transfer efficiency of the pile is investigated by considering the effects of the soil arch and the tensile membrane. Comparisons of the present solution results with those from available analytical methods and standards ensure its accuracy and feasibility. Parametric studies show that the load transfer efficiency decreases exponentially with an increase in the subgrade reaction coefficient and increases slightly with an increase in the consolidation coefficient of the soil. The effects of the soil arch and membrane tension increase sharply at first and then become constant as the embankment height increases.

Key words: load-bearing reinforced piled embankment, triangular pile arrangement, concentric spherical soil arching, soil arching effect, membrane effect