Testing the Response of Box-Type Soil-Steel Structures under Static Service Loads

The paper presents the static loading of four long-span deep-corrugated steel box culverts with spans of 14 and 8 m. The tests, which were part of a series of full-scale tests, involved strain and displacement measurements carried out at different cover depths under the load of a truck. Two of the culverts were stiffened at the crown. The test results showed that the stiffening applied on the culverts is quite effective and that plain structure is more sensitive to cover depth compared to stiffened structure. The crown stiffening is more effective under shallow soil covers. The maximum displacement of plain structure is approximately twice the maximum displacement of the stiffened structure measured at 45-cm depth of cover. The Swedish and Canadian design methods are conservative when estimating live load moments but they underestimate live load thrusts. The measured maximum thrusts are up to four times larger than the calculated design values where the variation depends on the size of the culverts and the depth of soil. The culvert size has considerable influence on the thrusts and moments generated at the crown centerline, which could be implemented in the design models.