Measured Response of a Deeply Corrugated Box Culvert to Vehicle Loads

Metal box culverts constructed from 400mm by 150mm plate resist applied loads largely in flexure and design predominantly focuses on bending moments rather than the thrusts considered for conventional corrugated plate. Moment distributions, deformations and thrusts have been measured during tests conducted on a deep corrugated metal box culvert (span of 10m, rise of 2.4m) and are reported for two loading conditions. First, culvert response is reported for a truck of total load 240kN placed at eight locations across the culvert, with cover of 1.04m. Next, culvert response is reported for larger loads applied through a steel frame with dimensions of the standard AASHTO H20 tandem. Loading under the dump truck demonstrates the changing pattern of circumferential bending, with peaks moving across the culvert under the tandem axles at the rear of the truck. Bending for a truck weight of 240kN has a peak value less than 12 kN.m/m, which is less than 15% of the yield moment for the steel structure. The measured response of the deep corrugated metal culvert under fully factored CHBDC CL-625-ON (close to fully factored AASHTO HS20) tandem axle loads (591 kN) was below first yield.