Recently, soil-steel bridges have become more commonly used as railway-highway crossings because of their\r\neconomical advantages and short construction period compared with traditional bridges. The currently developed\r\nformula for determining the minimum depth of covers by existing codes is typically based on vehicle loads and\r\nnon-stiffened panels and takes into consideration the geometrical shape of the metal structure to avoid the failure\r\nof soil cover above a soil-steel bridge. The effects of spans larger than 8 m or more stiffened panels due to railway\r\nloads that maintain a safe railway track have not been accounted for in the minimum cover formulas and are the\r\nsubject of this paper. For this study, two-dimensional finite element (FE) analyses of four low-profile arches and four\r\nbox culverts with spans larger than 8 m were performed to develop new patterns for the minimum depth of soil\r\ncover by considering the serviceability criterion of the railway track. Using the least-squares method, new formulas\r\nwere then developed for low-profile arches and box culverts and were compared with Canadian Highway Bridge\r\nDesign Code formulas. Finally, a series of three-dimensional (3D) finite element FE analyses were carried out to\r\ncontrol the out-of-plane buckling in the steel plates due to the 3D pattern of train loads. The results show that the\r\nout-of-plane bending does not control the buckling behavior of the steel plates, so the proposed equations for\r\nminimum depth of cover can be appropriately used for practical purposes.
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