Three‐Dimensional Analysis of Flexible Circular Culverts

Abstract

The use of three‐dimensional elastic finite‐element analysis is investigated for shallow buried circular culverts responding to vehicle live loads. The analysis is an efficient semianalytic procedure that uses a two‐dimensional finite‐element mesh across the culvert and harmonic modeling (a Fourier Integral) along the culvert axis. The analysis is briefly described, with reference to a three‐dimensional surface load problem with known solution. This is followed by an application of the procedure in order to examine the behavior of a large‐diameter circular steel plate culvert tested by Bakht. Comparisons are made with two‐dimensional finite‐element calculations, following conversion of three‐dimensional loads into “equivalent” line load. It is found that the three‐dimensional analysis provides improved predictions of hoop‐thrust distribution. The significance of the orthotropic properties of the corrugated plate and the finite culvert length are examined, as well as the sensitivity of estimated hoop thrust to choice of soil modulus.