Soil-metal structures are a popular form of constructing short span bridges. The design provisions for these structures are provided in the Buried Structures section of the Canadian Highway Bridge Design Code. Historically, the development of these structures grew out of the corrugated steel pipe industry. However, their use has expanded well beyond the basic pipe usage as a hydraulic conduit into a legitimate bridge form. In keeping with the conference theme of “Adjusting to New Realities“, the soil-metal structures industry has had to adjust its products to meet the demand of several new realties including optimizing designs to address the rising costs of raw materials and labour, more mechanistic design approaches relying on rigorous analysis rather than empirical rules, the demand for more durable structures and the need to span greater distances or sustained greater loads. This paper will discuss the joint research work undertaken to address these demands. A key element of this research has been the implementation of structural monitoring systems in key projects prior to construction and backfill. The data collected from these structures has been used to verify safety and analytical assumptions. Typical design approaches rely on two dimensional models. Work at Dalhousie has also focused on the development of three dimensional modelling approaches. Aluminum is an attractive material from a durability perspective and has been used in the past for box-type structures with spans limited to less than 8 m. The paper will also review the development of a new stiffening rib product allowing aluminum to be used in box-type structures of up to 12 m spans. These innovations have allowed Canada to have some of the longest soil-metal bridge structures in the world.
