The citizens of Ohio’s Indian Hill value the village’s rural atmosphere, reputation for safety, strong sense of history, and its proximity to the pulse and culture of Cincinnati. Over the years, one of Indian Hill’s natural treasures, Sycamore Creek, had seen its water-carrying capacity reduced by erosion, silt buildup, residential yard waste, and fallen trees. That dwindling capacity was challenged by torrents of rain in Hamilton County, which created flash floods that carried serious consequences for the surrounding area.
|
Sycamore Creek flows underneath heavily traveled Remington Road, or SR-126, where in the 1930s a cast-in-place twin box culvert was installed. With the culvert deteriorating at a rapid rate, and the increased volume creating a large scour hole, the Ohio Department of Transportation (ODOT) began looking at replacement options. But the project was not without obstacles.
The challenge
“There were multiple challenges to meet on this project,” said Palmer Engineering project manager Bronson Funke, who stressed the need to minimize road closure time. Crews would have to negotiate a large skew under high fill, limited access for construction equipment, and potentially unstable slopes and dewatering. They would also have to work around power lines and the threat of flash flooding.
“Ultimately, we needed a structure that could handle the design flows, be installed relatively quickly, and be able to handle more than 25 feet of fill,” said Funke, who wanted to provide alternatives that would allow the contractor to decide which product was best for his construction approach, in an effort to reduce project costs, shorten the construction duration, and result in the best finished product.
The options
Palmer Engineering evaluated several options for the site including precast concrete arches and structural steel plate. Two concrete arch options were evaluated, including CON/SPAN and BEBO. Additionally, a SUPER-SPAN steel plate structure was considered in the earliest phase. Because of the topography, amount of fill, location, installation time, and geotechnical considerations, a precast concrete arch bridge was selected as the best option for the replacement.
ODOT chose a BEBO Arch structure to replace the twin 14-foot-wide by 10-foot-high concrete box culverts. The BEBO C-Series was selected as the most efficient solution over the CON/SPAN option for this project based upon two factors: First, the arch’s inherent structural capacity, resulting from its half circle shape, allowed for a thin structural frame; Second, the reduced foundation cost and simplified design, resulting from the increased height offered by the shape of the C-Series BEBO, meant reduced soil cover and reactions to the foundation.
The solution
Sunesis Construction was brought in to install the 336-foot-long structure. Two cranes were used to lift and place the precast arch pieces into place and due to slope instability on the west bank of the stream, both cranes had to be located on the same bank. The twin-leaf precast pieces were lowered 40 feet into place, and the cranes were required to work in assembly-line fashion due to power lines on the north side (inlet) of the road, which could be shut down only for a few hours a day, and never when the temperature was greater than 90 degrees.
Sunesis worked diligently for five days to lift each half unit off of the trucks, orchestrate the cranes, align the units, and make the attachment at the crown joints. The new structure has a 30-foot span and a 15-foot 4-inch rise, and marks the first twin-leaf BEBO structure for ODOT.
Dave Brodowski is the precast product manager for CONTECH Construction Products Inc. He can be reached by e-mail at dbrodowski@contech-cpi.com.