Numerical Analysis of Piled Embankments on Soft Soils

The construction of embankments on soft soils is a common problem. Soft soil cannot sustain external loads without having large deformations. Piled embankments system provides a possible solution for the construction of roads and railways over soft soils. Until now, the system behaviour could only be described by analytical models such as those included in British or German codes. This paper describes research undertaken to investigate the effects of pile embankment construction in soft soils. Experimental results are used to help investigate arching effect developed due to differential settlement between pile and surrounding soft soil. A numerical parametric study was carried out to examine the impact of various soil parameters on the pile-embankment system behaviour. The outcome of the parametric study implemented using numerical analysis has been investigated and discussed throughout this paper. Based on the numerical analysis carried out in this research, it was found that the earth pressure coefficient normalized by the passive earth pressure K_p plotted on a vertical profile at the midpoint between piles can give a good illustration of arching behaviour. The findings presented in this paper can be considered as guides for numerical analysis and design criteria of soil arching for embankments constructed over piles.