To improve the understanding of the soil aching effect in the embankment fill

a parametrical study using finite element method is performed. In the analysis

the pile spacing

the fill height and the friction angle of embankment fill were varied. It is found that for low fill height relative to the net pile spacing

H/(s-a)≤1

the failure surface is vertical or slightly inclined which starts from the pile edge and goes through the whole fill height. For H/(s-a)≥1.5

the developed failure surface is similar to that assumed in the Terzaghi’s bearing capacity theory; there are triangular elastic zone

radial shear zone and passive zone in the embankment fill. By using the failure surface shape determined from the FEM

a two-dimensional simplified method to evaluate the soil arching effect is proposed. The computed stress reduction ratios are compared with FEM results and the experimental data collected from literatures; it is found that the present simplified method can predict reliable results.