Numerical analysis of application for pile-supported reinforced embankment in subgrade widening engineering

In order to investigate the mechanical behavior and treatment effect of pile-supported reinforced embankment under load in subgrade-widening engineering, a 3D finite element model was established, foundation soil was simulated by using soil-water coupling element, geogrid was simulated by using 3D membrane element, the changing-status non-linearity of pile-soil interface was considered by surface-to-surface contact elements, and the working mechanism of pile-supported reinforced embankment was validated by soil arching effect, tensioned membrane effect of geogrid and pile-soil interaction.Analysis result indicates that the maximum tension in geogrid occurs at the edge of pile cap under the toe of existing slope, and geogrid tension gradually decreases from the edge; pile-supported reinforced embankment can reduce the differential settlement of foundation from 50.0 cm to 8.3 cm, excess pore pressure from 63.7 kPa to 11.0 kPa, and avoid the appearance of reverse slope at the top of old embankment.Meanwhile, there are significant settlement and excess pore pressure at the foundation under the old embankment, so it is important to treat the foundation under the old highway slope.