When ODOT discovered cracking, excessive spalling and exposed rebar in the top of culverts that passed under I-675 in Centerville, Ohio, options to replace, repair and/or rehabilitate were very limited. Closing I-675 was not a viable option, so complete removal and replacement was quickly ruled out.
ODOT engineers originally decided to reline the twin 12’ x 6’ box culverts with 66” diameter aluminized steel pipes. They found that the lost hydraulic capacity had to be supplemented with a 96” diameter tunnel, installed next to the box culverts to assure passage of peak stormwater flows. Additionally, potential maintenance required to keep the pipe entrances free from debris and operating at full design capacity was a large concern.
Along with ODOT, Contech developed an alternative solution. An 11’6” x 4’3”, eight-gauge, galvanized steel MULTI-PLATE arch was placed inside each 12’ x 6’ culvert, and concrete footings were built in the bottom corners of the existing box culverts. This option reduced material costs and increased the hydraulic capacity of the pipe option, while minimizing maintenance concerns.
For installation of the plate structures, Capitol Tunneling developed a “pulling harness” and a powerful pneumatic winch system to pull the arches in place. A steel channel cast in the top of the footings facilitated the pulling and placement operation. The MULTI-PLATE arches were grouted in place and potential shutdown of I-675 was averted.