Numerical Analysis of Load Reduction Using Geofoam for Rigid Culvert under High Embankment

For high fill embankments, culverts need enough structure sizes and stiffness to resist large vertical earth pressure which conduced the culverts are not safety and costly. Tests and theories have identified that geofoam is a perfect compressible material to reduce the vertical load on the culvert. Load reduction numerical analyses for high fill culvert using ANSYS finite element software were done. The function of Death and birth element of ANSYS was used to simulate the process of soil paving by layers, different thicknesses and densities of geofoam were considered in the numerical models. The results show that geofoam can obviously reduce vertical pressure by transferring shear forces to the lateral soil prisms, with the same density of geofoam, and the thicker of geofoam the less pressure acted on the culvert. The thicknesses of geofoam are not linear relationship with the vertical pressure on culvert, with the thickness of geofoam increasing, the effect of load reduction is decreased, and the optimum thickness can be decided by calculating curve. After using load reduction method, the culverts can be designed small sizes and stiffness.