Adding a new Life Sciences Education and Research Building to Loyola University's crowded urban campus has required delicate excavation work and careful crane choreography.

Workers had to maintain the integrity of adjacent buildings, relocate utilities, work in the extremely shallow water table on the Lake Michigan shoreline and keep one of the campus' arterial roadways functioning while tunneling beneath it.

The $40 million project began May 12 and is scheduled for completion in November 2004.

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"The building abuts, but does not share a common wall with, the school's current chemistry building," said Ryan Mahoney, project manager for general contractor Power Construction Co. of Schaumburg, Ill.

Mahoney added that keeping the neighboring building stable required earth retention work and careful excavation.

Steven Muzillo, project manager for Bensenville, Ill.-based Lindahl Brothers Inc., the project's excavator, said that before sheet piling was installed, "we had to probe and remove any existing foundations that might have interfered with the new construction."

He said that with the proximity of the neighboring building required his crews to dig straight down in small sections, to probe for old foundations and then backfill that hole before moving on. He called the three-day process "very standard" in urban construction around existing structures.

Tiebacks under the adjacent building help to maintain that structure's stability.

"We have been doing vertical and lateral surveys on the existing structure since we started digging," which is consistent with work on a site of this type, Mahoney said.

Muzillo said installing sheet piling the entire footprint of the building was a way of dealing with the site's proximity to the lake.

"We were digging in sand just a few hundred feet away from lake Michigan," he added.
"The groundwater conditions were an obvious obstacle." The sheeting served as a bathtub of sort, allowing crews to pump water away from the site.

Tunneling in Rogers Park

Excavation for a tunnel, designed to connect the new building with a related structure across the street, presented additional water concerns.

"If we couldn't maintain the tunnel in a watertight fashion, water would come in and flood not just the tunnel but the adjacent building," Muzillo said.

The tunnel also presented a scheduling issue because it runs underneath a major arterial on the campus.

"The university asked us to get the tunnel squeezed in between the summer and fall sessions, which meant that we could close the road for only about three weeks," Mahoney said.

Using what he called a "tremendous overtime push," Mahoney said crews got the 150-ft.-long, 16-ft.-deep tunnel in place and reopened the road on time.

But the biggest challenge of digging the tunnel involved utilities. A 12-KV Commonwealth Edison line, which ran perpendicular to the tunnel, had to remain in place and in service throughout the project.

"We had to ground our equipment so that it would not cause serious injury to anyone if there was a break in the line," Muzillo said. "Commonwealth Edison was there with their people on standby through it all."

He added that the university put security personnel on the site, too, in order ensure student safety.

The tight site has required careful crane choreography and staging of work.

"We didn't have enough room outside the site to mobilize a crane, so we put the crane down in the basement," Mahoney said.

He explained that the building was divided into halves. The crane was placed in the south half of the building's basement and used to set steel in the north half. When that was complete, the crane was moved to the southeast corner of the basement to set steel for the southwest corner. The crane will be placed on the site to set the steel for the southeast quadrant of the structure.

"All the major mechanical components for the building are in the north half of the job," Mahoney said. "Setting the steel this way has allowed us to begin major mechanical mobilization, such as generators, gear rooms and air-handling equipment, with the steel still in progress on the other half of the building."

Mahoney said it has been a tough job for the ironworkers who have had work in extremely tight quarters.

Site Affects Design

The tight site had an impact on the building's design as well.

"We had to come up with a design that would tie the three existing science buildings together and work as hub for all of them" said James Lubawy, vice president and project manager for architecture firm Solomon Cordwell Buenz and Associates Inc. of Chicago. Those three buildings were a 1950s brick structure, a 1960s precast structure and a tall Art Deco building, called the Skyscraper, built in the 1920s.

"Our building is brick and glass with a corner tower developed to relate to the Skyscraper," Lubawy said.

A deliberate, diagonal traffic flow through the building allows students to come in through the main entrance on the southeast corner and move toward the campus, exiting at the northwest corner of the building.

But the structure's striking four-story atrium, complete with floating pedestrian bridges and an ornamental circulation stairway, is the element that unites student and faculty.

"The atrium faces the north," Lubawy said. "That whole side of the building is a four-story curtain wall. It takes advantage of the north light and it is open to the campus.
This allows the kids inside to see activity outside and draws people in, creating a hub."

Meeting Codes

He added that working closely with the city of Chicago and the university helped avoid what could have been major code problems.

"You always want to exceed code," he said. "But some of the codes were written as though we were building a major chemical fabrication plant. The science building definitely has chemicals in it, but in minuscule quantities when compared to a chemical production plant."

Lubawy said that an ongoing dialog between the construction team, city and university allowed all parties to understand what sort of chemicals would be used, and in what quantities, and therefore to understand what sort of codes the structure really had to meet.

He added that high-rise safety requirements had to be met because the high ceilings needed to accommodate exhaust ducts for the various labs made the building qualify as a high-rise structure.

At the same time, the structure had to meet the life-safety requirements of a school structure. Sometimes one set of requirements conflicted with the other.

"We had to sit down with the Fire Prevention Bureau to work out how to mesh these sets of requirements," Lubawy said. "The outcome of our discussions is that we are very much in line with the requirement changes that have happened after that terrible fire last fall [the Oct. 17 fire in the Cook County Administration Building that cost six lives].

Lubawy added that the building also performs better than energy codes for a structure of this nature require.

"A laboratory consumes a tremendous amount of energy because you have to ventilate chemicals on a constant basis," he said. "In a school building you have peak periods when a lot of teaching is going on and times when there is very little."

He added that designers diversified energy loads, and the building's exhaust volumes can be adjusted to reflect the daily usage pattern.