When it was built nearly 90 years ago, Wacker Drive set an example for state-of-the-art bridge and highway construction in Chicago, IL. Its construction represented the finest reinforced concrete work of its day, with innovative, octagonal columns supporting the drive. Seeming to symbolize Atlas supporting upper Wacker Drive, the design provided both architectural beauty and purpose-built strength.
Lower Wacker Drive combined form and function: As one of the first streets to allow intermodal freight transfer, it served as a dock for boats that would unload cargo to waiting trucks. Additionally, the structure incorporated a modernistic lighting method on the lower level that concealed the fixtures in the top of the columns. The radius of each electric illumination was designed to overlap the illumination of the next lamp to eliminate dark spots during driving.
Other innovations accomplished by Wacker Drive include its winter work schedule. In the early 1920s, construction work typically halted during cold weather months, but the project engineers developed a method of enclosing the work with tarpaulins, heating it with fire contained in barrels, and pouring the concrete. Even though outside temperatures hovered below zero, inside the “tents,”concrete was poured into forms at approximately 100-degrees Fahrenheit. A protective covering of marsh hay was then packed around the concrete forms. Temperatures were monitored daily, and up to seven days later could still register as high as 70 F degrees, no matter what the chill outdoors.
Not only did the technique speed progress by allowing crews to work year-round, but dedicated construction workers set daily speed records as well. On Aug. 10, 1925, crews poured 1,080 cu. yd. (826 cu m) of structural concrete in one-half block of slab.
Beginning at 6 a.m., crews worked through until 1:30 a.m. the next morning, to set a new world record. Twelve days later they broke that record when the same amount of concrete was poured under the same conditions in one hour less.
Speed did not compromise safety then or now. Mid-Continent Construction Company, who performed more than 70 percent of the job in the ’20s, didn’t suffer any serious accidents on the project.
The concept of a roadway with an upper and lower deck was the brainchild of architects Daniel Burnham and Edward Bennett. They presented their vision to the Commercial Club of Chicago in 1909, with the innovative roadway serving as the cornerstone of their intriguing plan. Charles H. Wacker, chairman of the Chicago Plan Commission, embraced the idea, which was a radical departure in purpose and construction from contemporary structures.
His dedication to ensuring the completion of the project earned his immortality by adopting his name upon completion of the work in 1926. Originally expected to cost more than $8.5 million, the actual cost of constructing Wacker Drive in 1922 rang in $500,000 under budget. It contained more than 1-million steel rods — equal to 7,500 tons (6,750 t) of reinforced steel — 30-million ft. (914,400 m) of lumber, 250,000 sq. ft. (23,226 sq m) of sidewalk, and 15,000 ft. (4,572 m) of curbing. The total length of Wacker Drive is 2 mi. (3.2 km): 1.2 mi. (1.9 km) running east/west and 0.8 mi. (1.3 km) running north/south. Sixty percent of it runs alongside the Chicago River.
This vital artery into, out of and around the heart of Chicago serves more than 60,000 cars, thousands of pedestrians and 1,000 boats each day. Running in all four compass directions, Wacker Drive intersects with 20 streets in the Loop. It was designed to be a distributive artery for seven major north/south streets and nine east/west streets, with its lower level providing a highway for heavy traffic, uninterrupted by traffic flow from intersecting streets. The lower level also facilitates deliveries and refuse pick-up from 57 high-rise buildings as it relieves traffic congestion. The upper level serves the central business district. Twelve ramps join the two levels and 19 movable bridges are connected to it.
Wacker Drive is on The Illinois Department of Transportation’s (ILDOT) list of historic bridge structures, and thus is eligible to be named a national landmark. But the 90-year-old structure needs repairs and updating. The goal of the revitalizing and rehabilitating Revive Wacker Drive project is to unite the historic aspect of the bridge to the physical demands required by modern traffic. The project plan also calls for an enhanced and unified streetscape in order to provide Wacker Drive with a unique identity along the river. To preserve the look of the original facade, the same material — Indiana limestone — used along the riverfront will be incorporated.
Goals and Procedures
Objectives of the project include rebuilding the structure; improving access and safety on the lower level for deliveries to existing and expanded businesses; easing traffic flow on adjacent streets; creating a connection between the riverfront and the Loop; enhancing the streetscape; maximizing median areas for green space; and development of a river walk. In addition, the plan includes ideas for increasing safety by improving several intersections and increasing the vertical clearance height on the lower level to reduce current height restrictions on delivery vehicles.
Construction will be conducted in sections under three different contracts, with some work along sections of Wacker Drive occurring simultaneously. The work pattern will be dictated according to how Wacker Drive will be built, although in general work will progress geographically so as not to close too many avenues at once. A critical factor in the project plan concerns the support of the entire structure during construction.
Stan Kaderbek, deputy commissioner and chief bridge engineer, explained that the separate contracts were drafted to keep each one within a reasonable size for competitive bidding. Contract A runs between State Street east and Franklin Street east; Contract B covers the area between Franklin east to Randolph north/south; and Contract C consists of the space between State east and Michigan west. Contract A is currently underway; B is now out for bid; and C was advertised for bid on July 23. Kaderbek said he expects them all to be working by September. The riverwalk is expected to be under construction in 2003.
The project plan calls for phased closing of north/south streets as construction advances, thus allowing as much access to the roadway as possible. Some closures will remain in effect until November 2002, but the project plan intends to shut down roads in stages to avoid undue congestion and detours. Phase I of Contract A began in late February with the closing of the State Street and Wacker Drive intersection.
Phase II began in June with the opening of that intersection. The RTA and CTA lines of buses and trains will continue to operate throughout the project. In addition, boats operating on the Chicago River offer another form of transportation as an alternate route to driving the Loop.
Progress
Contract A is currently in the demolition stage, according to Kaderbek. “It’s a block-by-block demo,” he said. “We’re working on the routes in and out of the Loop. As we progress, we’ll continue to open one as we close another. State Street had to reopen before we could close LaSalle. We expect to close Wall and Dearborn around Thanksgiving; Clark and Franklin — which would be Contract B — on January 1; and Wabash by next April 15.” New detour routes are developed for the cross streets as each one closes.
Crews are removing the superstructure down to the caisson caps. As much as possible, they will use the existing caissons to build the new caps, following the guidelines of Section 106 of the Federal Code for Historic Preservation, Kaderbek explained.
Because the bridge is listed as an historic landmark, careful consideration must be paid to its appearance, and strict adherence to guidelines must be followed. “We have to maintain the look of the facade,” noted Kaderbek, “even though the new structure is going to be radically different.”
To help maintain the continuity, much of the original Indiana limestone is being reused. Limestone from the facade, benches, obelisks and more is surveyed, catalogued and judged to be either worthy of keeping or requiring replacement. All limestone that is kept for reuse must be tagged, cleaned and returned to its place. Equally challenging and time-consuming is the work of replacing pieces to match the existing limestone in order to maintain the historical character.
Team Work
Currently there are about 10 subcontractors on the job, working under general contractor Walsh Construction. Kaderbek said that a federal job like Wacker Drive requires contractors to perform a certain amount of the work, so many of the subs being used are “two-in-one” subs.
Kaderbek happily reported that crews are approximately four weeks ahead of schedule on bid blocks, and two weeks ahead of schedule on LaSalle Street. “The critical path is ahead of schedule,” he confirmed.
The upper level roadway is scheduled for completion by October 1, 2002, but Kaderbek said he expects to finish up work early. Similarly, he expects to complete work on the lower level before its scheduled November 1 deadline. “The arch work and streetscape will be done by November 2002, except for east of State Street,” he added.
Good weather — except for a rainy spell early in June — has helped Wacker Drive’s crews keep on task. Kaderbek reported that there is very little shift work required. “The guys are working 10- to 12-hour days, five or six days a week right now,” he said.
He noted that the contract specifies incentives to complete work ahead of schedule. Because Wacker Drive is the only access for many of the businesses along the route, the city has included handsome incentives for work completed early. Kaderbek estimated that up to 200,000 vehicles use Wacker Drive each day, with 20 bus routes lining the roadway. With that much business at stake, it’s no wonder the city is anxious for early completion.
“We’re maintaining access through construction,” he continued. “That includes parking and loading docks.” But he added that in an attempt to facilitate work in the area, the city has adopted drastic measures to keep people off the streets during peak times. During the hours of 7-9 a.m. and 4-6 p.m., Kaderbek said, there are no drop-offs, no deliveries, no parking.
“The city, businesses and the people have been very supportive,” Kaderbek said. “We keep them all informed in advance of what’s going to be closed so they can make alternate travel plans, and we haven’t heard many complaints. What’s interesting is that CTA and Metro aren’t reporting a big increase in ridership, so I guess the people are using the detour routes pretty well.”
Assisting in public relations, communication, problem-solving and on-schedule progress is the construction management team of Alfred Benesch.
“They work through any problems we encounter,” said Kaderbek, “and get answers to the crews immediately. With this kind of deadline, you can’t afford to have people stand around on the job site and wait for answers. We also have three full-time city staff dedicated to solve problems on the project. The city understands the importance of keeping the job moving.” And everyone involved appreciates the importance of the work they’re doing to revive Wacker Drive.
Today's top stories
