The term security wall may not inspire designers, but by no means do these functional stalwarts need to be boring.
By Mark Crawford
When Commonwealth Edison Company hired Chicago-based contractor The BarTech Group to discuss security walls for a substation project in Romeoville, Ill., the utility company proved this point when they stressed the walls needed to be both secure and visually appealing.
The resulting design for the precast security wall around the perimeter of the station included 53 8-foot-tall precast columns with 51 panels, spanning an average 19 1/2 feet in length. Each panel carried a smooth coping with a 3/4-inch reveal running the length of the panel. A special column cap design helped make the columns more attractive.
Utility Concrete Products of Morris, Ill., provided the precast units for the project. A formliner was used for the panels and columns to achieve the 1 1/2-inch reveal ashlar stone texture. “The walls are designed to provide added security for the substation, as well as be aesthetically pleasing for the surrounding community,” said Tom Heraty, vice president of sales and engineering for UCP.
Steel security fencing installed on top of the wall adds an additional 2 1/2 feet to the height of the wall and a steel gate is connected to embed plates in the adjacent columns.
“The wall had several kink points throughout its length,” added Heraty. “This required custom columns with angled keyways to allow the panel to be properly connected and aligned.”
A fabrication schedule established between UCP and the contractor maintained the installation date requirements of the owner. Predetermined delivery start times and spacings between trucks ensured the installation of the panels and columns occurred on time. Upon arrival at the job site, the columns were rotated upright and set on top of cast-in-place concrete piers so that the base plate holes in the columns aligned with the anchor bolts previously cast in the concrete foundations.
It was imperative that The BarTech Group accurately laid out the locations of the bolts to avoid any alignment conflicts in the field. Plastic shims between the top of the pier and bottom of the columns created a uniform bearing surface. The panels were then smoothly released though the keyways of the columns.
Safe, secure and stylish
When the walls were completed, the UCP team was proud of the solution that accomplished the security and design goals of the client, including a first-time use of the color gadget gray.
“We take pride in our ability to provide great-looking products while maintaining tight tolerances,” said Heraty. “During the design stage, without the benefit of seeing all the different components installed, it can sometimes be difficult to really see how the final product will look. The client was very pleased with our attention to detail and precision, and everyone thoroughly enjoyed the color scheme and the patterned precast walls.”
Mark Crawford is a Madison, Wis.-based freelance writer who specializes in science, technology and manufacturing.