Numerical Analyses of Soil Arching in Rigid Pile Supported Embankments

The piled embankment - consisting of the foundation, pile, pile caps, and the earth-filling embankment - is a complex soil-structure system. One of the working principles of the rigid pile supported embankment is the soil arching effect. Many factors - such as the surcharge load over the fill, consolidation of soft soil foundation, and differential settlements between piles and around the soil - would play a role. In this paper, a numerical model of rigid pile supported embankment was built using ABAQUS software. A series of numerical analyses was performed to research the shape of soil arching for different fills and different loads on the fill. In the numerical analyses, the fill of embankment is silty clay or gravelly soil, and the material of foundation is soft soil. Silty clay, gravelly soil and soft soil are simulated as elastic-plastic material following the Coulomb friction law. Piles conformed to a linear elastic law. After the calculation, the following results were obtained: (a) the shape of soil arching in 2D would be a trigon; (b) soil arching height would grow with loads on the surface of fills; and (c) the angle of soil arching changed with the load increasing on the fill and depended on the fill characteristics, such as peak internal friction angle, cohesion and elasticity modulus.