An entire town is under construction on Chicago's lakefront.

The first structure of Lakeshore East, a 28-acre, mixed-use development that could eventually contain 15 buildings and 5,000 residential units, broke ground in August and is slated for occupancy in November, with final occupancy in February and March.

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The initial building is an $84 million, 480,000-sq.-ft., 209-unit condominium tower called the Lancaster. It will rise 29 stories.

The site, on a former golf course between Illinois Center and North Lake Shore Drive, was largely landfill over what was once a shipyard/rail facility on Lake Michigan.

"The amount of utilities on the site was a challenge right from the start," said Joel Kuna, project manager for Chicago-based general contractor James McHugh Construction Co.

Kuna said workers had to deal with five banks of Commonwealth Edison cables, water feeds for the city of Chicago's water treatment facility and gas and phone lines.

"Everybody comes right through my corner of the project, right down the center of the job between the caissons," he added.

The exact location of the utilities was something of a mystery.

"There was some survey information about things that were supposed to be there," said Brian Scanlon, vice president and project manager for the project's structural engineer, Chicago-based Chris P. Stefanos Associates Inc. "But when we got closer to construction, we found out there was a lot more there than the drawings showed and it was in places where it was not supposed to be."

The only solution was to unearth the utilities, map them and proceed from there.

Kuna said workers moved cautiously and slowly.

"We went in to probe for the caissons that had to be drilled and to remove any obstructions in the upper 15 to 20 ft.," said Steve Muzzillo, project manager for Lindahl Brothers Inc. of Bensenville, Ill., the project's excavator. "We knew there were some unmarked utilities, but we didn't know to what extent."

"Part of the problem was that the city didn't have a lot of these mapped so we were trying to find shutoff valves so we would know how to shut things off or reroute them in an emergency. The city was learning as fast we were."

The extensive probing took 10 to 11 workdays instead of the usual three to four.

Moving Water

Kuna said one of the discoveries was that water service to an existing high-rise was in the way of the project and had to be moved without any interruption in service to that structure.

"It was a week-long process of putting in pipe and turning it over," he said.

Muzzillo said the shallow water table at the lakeside site and buried debris presented yet more obstacles.

"Probing down below the waterline was difficult," he said. "We were probing blind with water coming in. There are old shipping yard slips well below the water table that had been filled in with whatever debris was left over when they demoed the rail- and shipyards."

Wood from old docks and boat slips, metal from the rail lines and remnants of an old sea wall were among the debris used as fill.

"We had to remove the buried material and sift through it to get the large, undrillable matter out," Muzzillo said. "We returned the drillable fill to the hole, things in the range of 4 in. in diameter or smaller."

He said it took an experienced backhoe operator to pull the debris from the hole.
Anything he could not pull up he would try to break off. Anything that could not be removed or broken off was left behind and mapped out so it could be avoided in caisson drilling.

Garage Redesigned

Once the utilities were located and mapped, it became apparent that a redesign of the Lancaster's garage, a structure that supports the first stage of a roadway that will eventually run through the development, would be necessary.

"We already had that part of the building pretty much done," Scanlon said. "We had to step back and sort out where to fit a caisson down between the utilities. Once we knew where the caissons could do, we had to redesign the garage."

He said moving the caissons to avoid the underground utilities required shifting column locations inside the garage and altering framing in order to support the structure itself and the overlaying roadway and the loads it will eventually bear.

He said that although the digging and redesign added a few weeks to the front end of the project, it would have added much more in time and cost if the underground obstacles had not been discovered until crews were mobilized and work was under way.

Muzzillo said caissons on the project ranged from 3 ft. to 5 ft. in diameter and extended to a depth of 90 ft. into the lakebed below.

The garage is a unique feature of the project.

"We have a Chicago Department of Transportation bridge deck sitting on top of a private garage," Kuna said. We have post-tensioned concrete on garage floors two, three and four, and we have a multistrand, tensioned bridge deck, all of it cast-in-place concrete."

Coordination was essential in getting the garage and deck in place before the tower was tall enough to hinder pouring concrete and pulling cables on the smaller structure. Kuna added that there was a limited window of time on the CDOT portion of the project, dependant on concrete strength, in which deck cables could be pulled and grout applied.

The road will go in piece by piece, constructed with each structure that sits adjacent to it, until it connects the various structures of Lakeshore East.

Fitting In

The Lancaster tower's facade will ultimately mesh with the structures planned for the future of Lakeshore East and the surrounding skyline.

"We are always fighting with the proportions of these buildings," said David Lencioni, designer with project architect Chicago-based Loewenberg + Associates Inc. "We are fighting length versus height."

He said the challenge was to make a strong statement with the 29-story tower while keeping the base of the building at a scale that has a relationship to the town houses that will eventually go in to the north and south of the tower.

"We have a base of precast concrete and a variety of punched windows that give it a scale that relates to the town houses," he added. "We also have a slick, reflective-glass curtain-wall system, and we took that one step further and gave it little curve to add more interest."

The gentle curve softens the lines of the building's exterior and adds interest to the geometry of most of the residential units on each floor.

The building's exterior also includes what Lencioni described as a "monumental stair and elevator" that will allow the public to go from Grant Park to the East Lakeshore's park below. He said the Lancaster's fitness center and party room will be located beneath the stairs.

"The stairs change direction about six times, with planters and various different elevations and a pedestrian bridge 54 ft. in the air," Lencioni added. He called the stairs and pedestrian bridge facet of the project "pure math."

The Lancaster's condominium units range in size from 710 sq. ft. to 1,779 sq. ft., with several 1,950- to 2,800-sq.-ft. duplex units on the lower levels. The single-level units are selling for $249,000 to $739,000, with the duplex units ranging from $642,000 to $928,000.