Beam-on-Springs Modeling of Jointed Pipe Culverts

Abstract

In this paper, an existing beam-on-springs modeling methodology is examined for suitability in estimating vertical displacements and joint movement in jointed pipe culvert systems. Methods of determining the modulus of subgrade reaction, ks, are used in beam-on-springs modeling and compared with results from laboratory tests on three buried culvert pipes. Pipes were buried in soil conforming to AASHTO specifications for buried structures and then loaded at the ground surface. Two of the methods provided reasonable estimates of ks for use with both rigid and flexible test pipes (with an average error of 25%). The first method relies on empirical parameters, whereas the second method relies on actual soil properties to estimate ks. This makes the second model more appealing. However, the second model is somewhat less accurate than the first (10% average error compared with 25% average error). Movement at the culvert joint was estimated by beam-on-springs modeling with a moderate degree of accuracy (within 52% error when calculating the maximum movements) because of the complexities of the jointed culvert system being modeled. Accordingly, results from a beam-on-springs model should be used conservatively.