Testing and Analysis of a Deep-Corrugated Large-Span Box Culvert prior to Burial

Deep-corrugated steel culverts (corrugation wavelength of 400 mm and amplitude of 150 mm) can be effective alternatives to short-span bridges. Because the corrugation dimensions are of a similar size to their minimum burial depths, the effectiveness of conventional orthotropic shell theory in soil-structure interaction analyses needs to be studied. Results from a large-scale laboratory test are therefore reported on a 10-m-span structure responding to a pair of vertical loads placed along the crown before burial. This test is then modeled by using three-dimensional finite-element analysis by using two different approaches. The first is on the basis of explicit modeling of the corrugated structure, whereas the second is on the basis of orthotropic shell theory. Comparisons are then made between the two sets of calculations and measured values of displacement and circumferential strain, and moment and thrust are calculated from measured strain. The corrugated analysis produced estimates of displacement at the center of the structure within 0.2% of measured values, whereas the orthotropic shell analysis yielded an error of 4%. The corrugated analysis provided strain values much closer to those that were measured. Moment and thrust values from the corrugated analysis were within 3 and 2% of the experimental values, respectively, whereas values from the orthotropic analysis erred by much greater amounts, particularly in the vicinity of loading points in which the orthotropic analysis cannot model local effects. Finally, the use in design of both explicit representation of the corrugated geometry and orthotropic analysis are discussed.