Finite element analysis of precast concrete box culverts

Prefabricated culverts have become economical alternatives for replacing deteriorating short-span bridges and cast-in-place box culverts. These prefabricated structures include reinforced concrete arches, four- and three-sided reinforced concrete box culverts, and metal culverts. The most commonly used type is the precast reinforced concrete culverts due to its durability, minimal field construction time, and favorable cost. Several test programs have concluded that ASTM C850 concrete box culverts are structurally conservative. The strain and deflection data from model testing were found to be in good agreement with field testing of prototypes. The availability of finite element analysis programs (SAP90, STRUDL, STAAD-III, etc.) provide structural engineers the opportunity to model three-dimensional box culverts more accurately. These programs can generate nodes, elements, specify various material properties, incorporate complicated boundary and loading conditions, and perform the structural analysis. They can also calculate stresses, strains, and deflections at any location in the structure as well as plot stress or strain contours of a given slab. The concrete box culvert can be idealized either as quadrilateral shell elements or solid brick elements. This paper presents a comparison of finite element analysis results with experimental data. It will also assist structural engineers in modeling and predicting the actual strength and behavior of any size concrete culvert subject to complicated boundary conditions.