Model Test on the Soil Arching Effect of Pile-Supported Embankments Using Transparent Soil

Pile-supported embankments have been widely used in subgrade engineering for highways and high-speed railways. Soil arching has an important effect on the deformation characteristics of pile-supported embankments. In this study, a new model testing apparatus and its test method for the soil arching effect were developed based on the transparent soil method and particle image velocimetry technique. The composition of the apparatus and the test steps were elaborated in detail. The development of the soil arch with the settlement of foundation soil was explored. The variations in the settlement of the embankment at different elevations and distances from the pile center were analyzed, and afterwards, the effect of pile spacing on the embankment settlement was discussed. The results revealed that a basin-shaped soil arch gradually formed in the embankment, with the settlement of the soil between the piles. The settlement below the arch boundary was larger, and the settlement above the arch boundary was relatively small. An equal settlement plane appeared in the embankment. The elevation of the equal settlement plane increased with increased pile spacing. The maximum settlement occurred at the center of the soil between the piles on the pile cap top plane. The settlement of the embankment increased as the pile spacing increased. This study provides a new solution for understanding the spatial effect of soil arching in pile-supported embankments.