The Illinois Tollway Oases have been providing much-needed respite for road-weary travelers since the first five of these commercialized rest areas were constructed in 1959. The state added two more Oases in 1968 and 1975, respectively, to offer food, gas and a place to stretch for motorists traveling across Illinois’ interstate highways.
But when the Illinois Tollway made the decision in April 2017 to expand the Move Illinois capital program and advance a $4 billion concept to improve the Central Tri-State Tollway for the more than 220,000 vehicles that use this portion of the highway daily, several of these structures had to be demolished to expand lane capacity and reduce congestion.
Alpine Demolition Services, St. Charles, Illinois, was first awarded the contract to demo the Des Plaines Oasis in 2014. After Chicago-based F.H. Paschen was selected as the general contractor overseeing the demolition of the O’Hare Oasis in 2018, Alpine was a logical choice to serve as a demolition subcontractor due to its familiarity with the project requirements and overall expertise.
“Alpine was chosen based on price, safety record and past experience,” Karsten Pawlik, VP of operations at Alpine, says. “Alpine successfully removed the Des Plaines Oasis, which was the identical structure to the O’Hare Oasis. The advantage of performing the Des Plaines Oasis was that Alpine had a proven plan, great safety record and production history on this type of structure. It gave the owner confidence that Alpine would be safe and successful on this project. Alpine was able to learn lessons from the Des Plaines project to become more efficient on the O’Hare Oasis demolition. Also, Alpine is a certified disadvantaged business enterprise (DBE), which helped meet diversification requirements for the project.”
Planning and tackling the job
Pawlik says that despite having familiarity with the project due to its previous work with the Des Plaines Oasis, Alpine undertook significant planning measures to ensure the O’Hare demolition would be a success.
After reviewing the plans and specifications, Alpine’s project management team conducted site visits while the project’s structural engineer, Indianapolis-based American Structurepoint, verified that the field conditions matched the plans provided and that there wasn’t any existing structural damage that needed to be considered. Following these inspections, a crane lift plan was crafted for the beam removal of the overpass, and once the demolition plan was formalized, it was checked by the structural engineer to make sure the structure would remain stable during the demolition process. After American Structurepoint did the calculations for the removal, the entire plan was submitted to the Illinois Tollway for approval, which it was granted in short order.
Following the completion of environmental surveys and asbestos abatement, Alpine located, disconnected and rerouted all utilities. Next, there were utility lines feeding an on-site gas station that was to remain that had to be removed, Pawlik says. Alpine then installed plywood and protective tarps under the overpass structure to prevent material from dropping to the roadway below.
According to Pawlik, the O’Hare Oasis project took special consideration because of its construction.
“This is a very unique structure, one of a handful of its kind, combining both a building and a bridge,” Pawlik says. “The most important part of the demolition strategy was to use a method that protected the traffic below. A demolition plan stamped by [American Structurepoint] was developed and followed in the demolition process. Wind loads, floor loads and structural stability of the remaining structure during the different stages of demolition were accounted for in the demolition plan. The structure had to be dismantled in a manner so that nothing was dropped on the roadway and all the material being removed had to be lifted down from the site.”
Pawlik says that maintaining traffic on the roadway and ensuring the safety of the passing motorists was of paramount importance to Alpine. Alpine planned work so that no demolition would be performed over live traffic, and the Illinois Tollway set times when lanes could be closed off at peak hours. Lane closure requests had to be made to Illinois Tollway and were never guaranteed based on other construction projects being performed. The lane closures, therefore, dictated the schedule and the process of the demolition sequence. Nighttime closures primarily were utilized to perform work over the roadway. Pawlik says that only 15-minute closures were allowed in the middle of low-traffic hours, and full closures had to be coordinated far in advance to get approval from the Illinois Tollway and to notify the public.
Pawlik says that Alpine used selective demolition techniques to remove the bridge-related components of the Oasis building, but that regular top-down building demolition techniques were utilized for parts of the Oasis not over the highway.
Some of the stages of the demolition included:
- Walls of the structure were left when possible to contain demolition material, and the interior was stripped of soft finishes.
- The roof was removed followed by the steel joists.
- The glass curtain wall was removed followed by the steel trusses.
- The concrete deck was saw cut and removed by “slabbing.” Once the deck was removed, the buildings and walls were removed in back of the abutments in preparation of the beam picks.
- A date was requested for 15-minute full closures of the highway to remove the beams. A crane was mobilized and beams were removed under the full closure windows.
- After the beams were removed from the site, the abutments on each side were removed.
- The general contractor restored the slopes after demolition was complete.
In the field, Alpine was proactive in reviewing the demolition plans with every member of the field team prior to each stage of the demolition. Alpine’s project management team would also check the team’s daily progress to make sure the plan was being followed. According to Pawlik, this oversight helped keep the project on track.
Pawlik says that Alpine utilized a range of equipment on the project, including two Caterpillar 349s, two Caterpillar 329s and one Caterpillar 305 excavator outfitted with various LaBounty tools. They also used four skid steers, one mini excavator and various other miscellaneous equipment for the demolition. A 500-ton crane was also used to remove the concrete beams over the roadway.
According to plan
Pawlik says that the project, which was started in October 2018, was completed in April 2019. Alpine’s crew of 12 was able to complete the project ahead of schedule and with no injuries to staff or motorists. While the job went off without a hitch, Pawlik says that the company had to overcome several notable challenges, including removing a building and bridge structure over one of the busiest highway corridors in the country, dealing with a structure that had load limitations on what size equipment could be used, and managing concrete beams that had an asbestos coating and required extra due diligence.
Pawlik says that Alpine’s diverse areas of expertise made the company uniquely qualified to handle these challenges and the other multifaceted requirements of this project.
“Most demolition companies specialize in one method. Alpine Demolition being one of the most versatile Chicagoland demolition contractors in all methods of demolitions made us best-suited for this kind of project,” he says. “When a good plan and a great team work together, projects will be successful.”
In all, the project yielded 6,000 tons of concrete and 500 tons of steel. The concrete was sent to local concrete recyclers for road construction while the metal was sent to local scrapyards. According to Alpine, 96 percent of materials from the O’Hare Oasis were ultimately recycled.
Thanks to Alpine’s emphasis on recycling, safety, project management and timeliness, the O’Hare Oasis demolition garnered the company the National Demolition Association’s Excellence in Demolition Award for projects in the $500,001 to $2 million category—an honor which Pawlik says is a significant accomplishment for the company.
“It is a great honor to win this award from the industry,” he says. “There were a lot of other great projects that we competed against, and it made me very proud of our team for coming out on top. It is nice to be recognized for all the hard work that is put into our projects.”