Load Performance of In Situ Corrugated Steel Highway Culverts

This paper presents the results of field performance tests of 39 in-service corrugated steel highway culverts in Ohio. The culverts had span lengths varying from $3.23\mathrm{m}$ $\left(10.6\mathrm{ft}\right)\text{to}7.04\mathrm{m}$ $\left(23.1\mathrm{ft}\right)$ and backfill soil heights over the crown varying from $0.27\mathrm{m}$ $\left(0.9\mathrm{ft}\right)\text{to}7.47\mathrm{m}$ $\left(24.5\mathrm{ft}\right)$ . Static and dynamic load tests were conducted by driving heavy trucks across the culverts. Static loads were applied at ten different locations above each culvert. Dynamic load tests were conducted at six truck speeds varying from $8\mathrm{km}∕\mathrm{h}$ $(5\mathrm{mi}∕\mathrm{h})\text{to}64\mathrm{km}∕\mathrm{h}$ $(40\mathrm{mi}∕\mathrm{h})$ . A portable instrumentation frame was installed inside each test culvert to monitor deflections. Strains on the culvert walls were also measured at 14 locations using strain gauges. 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 were nearly zero for deep culverts with backfill heights exceeding $4\mathrm{m}$ $\left(13\mathrm{ft}\right)$ . Maximum deflections correlate more closely to 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.