Abstract: The behavior of embankments is notably influenced by soil arching within embankments reinforced with rigid piles,including the decrease of total and differential settlements,the increase of stability of embankments and the reduction of construction period.However,understanding on soil arching is not enough till now.Soil pressures and settlements obtained from field tests of a highway project were analyzed.It was shown that,soil arching was significantly affected by differential displacements between piles and soil.The higher the embankment height as well as the smaller the pile spacing and the bigger the cap size,the higher the pile efficacy.The pile efficacies calculated by Hewlett & Randolph and the modified method were in good agreement with the measured data.