Box Culvert Project Doesn't Hinder Operations at Busy Ohio Airport

Below a taxiway at Port Columbus International Airport in Ohio, a new 192-ft long box culvert strong enough to take the weight of a loaded Boeing 727-200 airplane lies under shallow cover of four feet or less.

An important addition to the busy airport's stormwater drainage system, the specially designed culvert comprises 32 pre-cast concrete box units each 10 ft by 8 ft in cross section and 6 ft long. It was built under Taxiway J to carry the design-load of this Boeing 727 model, which has a two-wheel dual main gear assembly and a maximum tire load of 48,000 pounds. Distributed downwards through the flexible asphalt pavement and earth fill, this load exerts nearly 16,800 pounds per square foot on the box units.

One of the 10- by 8- by 6-ft pre-cast concrete box sections for the taxiway culvert is readied for installation.

Port Columbus International Airport, located within 500 miles of half of the U.S. population, is undergoing an expansion that will increase the number of gates from 27 to 57 to handle anticipated traffic increases. By the end of 1997, additional capacity was obviously called for and, as a result, the big construction project currently underway was initiated. The airport had reached a new level of 6.5 million passengers that year, with an average of 400 aircraft arrivals and departures daily.

Since construction activity involving taxiways and runways can be disruptive to airline schedules, inconvenient for the travelling public, and costly to an airport authority, the construction of this culvert had to be fast-tracked. It was scheduled as one of the first elements of the expansion project to get underway.

Design provides great strength
Two engineers with CSR Hydro Conduit, Dave McClintock in Diamond, OH, and Jim Shannon in Houston, TX, provided the special box design that incorporated an unusually thick wall and a heavily reinforced section, yet was still reasonable to produce. The 12-in. wall and 12-in. haunch section conformed to the minimum design requirements called for in the plans and specifications prepared by consulting firm URS Greiner of Hunt Valley, MD. Each heavily reinforced pre-cast concrete box with a 5,000-psi concrete compressive strength weighed 3.15 tons per foot. With a laying length of 6 ft, each section actually weighed 18.9 tons.

Within days of the award of the construction contract to George J. Igel & Co., Inc., of Columbus, the Delaware, OH plant of CSR Hydro Conduit received an approved design for the box units and prepared immediately to construct them. Since the project had to be fast-tracked, a speedy approval was required. This was achieved as a result of the closely coordinated work of the design engineer, the contractor and the pre-cast box producer. Less than a week following the design approval, the reinforcing steel and special fabrication equipment needed to produce the special box sections were on hand at the plant to allow production of the 32 units to proceed.

The pre-cast concrete boxes were fabricated using the dry cast method. This technique allowed greater flexibility in the design and a higher rate of production in comparison to a wet cast system approach. The Delaware plant production crew under the direction of Bryan Reardon, the plant superintendent, took only four days to turn out the 32 6-ft-long box units. All were made and ready for shipment to the airport site 2½ weeks from the time the contract bids were opened.

To round off the project the contractor quickly went to work upon taking delivery of the 32 box units and completed their installation to form the drainage culvert within a day and a half. The downtime of Taxiway J caused by this project was short and reportedly the airport continued to operate during the period without any related disruption of service.

Edited by Ian Lisk, Editor Emeritus, this article was based on information prepared by Dave McLintock, P.E., of CSR Hydro Conduit for Concrete Pipe News, a publication of the CSR Hydro Conduit.