Performance of Existing Corrugated Metal Culverts Under Live Load Application

This paper presents the results of performance tests of a large number of in-service corrugated metal culverts in Ohio. The test culverts had span lengths varying from 3.4 m (11 ft) to 6.4 m (21 ft) and backfill soil heights over the crown varying from 0.6 m (1.8 ft) to 7.6 m (22.3 ft). Static and dynamic loads were applied by using heavy trucks. The static loads were applied at ten different locations above each culvert. Dynamic load tests were also conducted at six speeds varying from 8 km/h (5 mph) to 64 km/h (40 mph). A portable instrumentation frame was installed inside each test culvert to monitor deflections. Strains on the culvert walls were also measured at fourteen locations using strain gages. Effects of backfill height and loading conditions are investigated. According to the experimental results, a plot of maximum culvert deflection versus backfill height shows a nonlinear relationship. Maximum static load deflections were found to be consistently larger than the maximum dynamic deflections obtained using the same test truck. Deflections are nearly zero for deep culverts with backfill height exceeding 4 m (13 ft). Maximum deflections correlate more closely to AASHTO equivalent line loads than to total truck weight. The data also indicate that culvert behavior is more difficult to predict when backfill heights are shallow because other factors, such as culvert age and condition and soil type, likely play a significant role.