Improving the Response of Soil-Metal Structures during Construction

Abstract

For economic reasons, manufacturers of soil-metal bridges have strived to build these structures under the shallowest possible depth of soil cover, below the one allowed by codes of practice. For such structures, special analysis is needed to circumvent or prevent the formation of failure mechanisms that may be triggered during construction or when subjected to traffic loads. Therefore, special features, such as transverse stiffeners attached to the metal shell and the use of thrust concrete beams, may be required to assist the corrugated metal shell in carrying the loads. In this paper, a novel design is proposed for such structures in which the surrounding soil is reinforced and the metal shell is tied into the soil. A finite-element analysis of long span soil-metal structures with shallow soil cover is carried out using these two designs. The analysis is verified and substantiated using field data obtained during the construction of an 18 m soil-metal bridge. Comparing the structural response from the two designs shows that the latter design can lead to a superior structure.