Finite Element Analysis of Concrete Box Culverts

Abstract

This paper presents the finite element results of a parametric investigation of three precast concrete box culverts subject to various soil covers and loading conditions. The three culvert sizes had a constant rise of 8 ft (2.4m) and different span length of 12 ft, 18 ft, and 24 ft (3.6m, 5.4m, and 7.2m). Six possible soil covers were also considered (0, 2, 4, 6, 8, and 10 ft). As the soil depth increases, the wheel loads were projected on the top slab using ASTM C890 formula. Lateral earth pressure was applied on the vertical walls which depends on the depth of the box culvert. The finite element method was used to analyze the structural behavior of the three-dimensional box culvert under different loading conditions using SAP 2000. The culverts were modeled using SHELL elements with six degrees of freedom at each node. The FEA results were compared with AASHTO plane frame analysis. In addition to live loads, all structures were subjected to three independent load cases: (a) overburden pressure alone, (b) overburden plus lateral earth pressure, and (c) overburden plus lateral plus bearing pressure.