Bridge approach settlement control using geogrid-reinforced pile-supported embankments

The paper describes a case of using geogrid-reinforced pile-supported (GRPS) embankments to control the differential settlement of bridge approaches. The results showed when the embankment height increased to 2.4 times the clear pile spacing, the soil arching effect fully developed. When the pile spacing increased from 2.5 m to 3 m, the weakening of the soil arching effect led to a 20% increase in the maximum subsoil displacement. Next, the influence of moving vehicle loads on the soil arch was studied using a three-dimensional finite element model of GRPS embankments. The study found that under moving vehicle load, the maximum vertical displacement at the bottom of the embankment increased by 6% to 9% compared with the static load. The maximum tensile force of the geogrid increased by 18% to 26% compared with the static load. Lastly, the influence of dynamic load parameters on the soil arching effect of GRPS embankments was analyzed. The results showed that changing from the half-sine load type to the sine load type increased the maximum vertical stress at the bottom of the embankment by 6%. The study also found that the vehicle wheel load was the most sensitive to the influence of geogrid tension.