Illinois Business Journal - 10 years of the 'new' Clark Bridge easing traffic flow to and from Alton

ALTON - It's no secret that Abraham Lincoln played a major role in Illinois - in its history, its pride, its tourism and "placing it on the map." He also spent a great deal of time in Alton - participating in the famous Lincoln-Douglas debate, visiting friends and representing legal clients. But who would have thought that with a little stretch of the imagination he may have inadvertently played a role in the Clark Bridge?

Shortly after the first Mississippi River-spanning bridge was built in 1856 between Rock Island and Davenport, Iowa, a steamboat hit the bridge and its owner filed a lawsuit. Lincoln argued for the defense and won the case with the statement, "A man has as a good a right to go across a river as another has to go up or down it." Bridges have spanned the Mississippi ever since.

Replacing the old 75-year-old Clark Bridge in Alton with the new one, which was completed 10 years ago, was a major undertaking that had been a long time in coming. The old bridge was narrow, curvy and had definitely seen its better days. A viable bridge crossing to St. Louis to the east was one of the most important aspects to the city's survival and helping the area to grow again.

The Illinois Department of Transportation, the U.S. Army Corps of Engineers and a team of engineers, designers and planners began work on the new bridge, with a 756-feet span and two 250-feet towers, in June 1990.

Joe Leach, civil engineer with the consulting engineering firm Crawford, Murphy & Tilly Inc., was the project manager. CMT was responsible for layout, inspection and documentation of the work.

The project required a lot of care on everyone's part, he said, because work was being conducted in close proximity to the barge lanes and workers were at times 50 feet below the water level. Lights and safety devices were used to warn the barges the workers were there and the barge industry took precautions, too.

"The contractors had barges near the cofferdams (temporary structures used to keep the water out) to work off of and for protection and that also created a warning sign for oncoming traffic," Leach said.

Leach said some of the unique aspects of the Clark Bridge include the fact that the cables sit in a saddle and are placed over the pylons.

"That was rather a unique feature for a bridge this size," he said. "Also, the foundation was used in a little bit different configuration in order to hold the heavy loads on the two pylons.

"The bridge is obviously very long and the layout work was somewhat difficult. It was a constant battle that required a lot of dedication on the part of our surveyor, to keep things on line and on grade," he said. "There were so many components to it. Much of the surveying had to be done very early in the morning to avoid expansion and contraction."

The Clark Bridge is a very flexible bridge, he said. Everything needed to be done very precisely in order to meet the 1/8-inch tolerance levels.

"You wouldn't normally realize there was movement or change in size on the bridge, but while measuring you find out the wind makes it deflect a little bit," Leach said. "And when the sun and heat hits it, it makes it expand, sometimes as much as three or four inches."

A major obstacle was knowing how long to make the final piece to make the final closure on the high-strength steel.

"The optimum temperature for setting the steel is 55 degrees," he said. "There's not a lot of difference, but enough to open and close the expansion joints. We were fortunate the day the closure of the steel was made, because it was just about 55 degrees."

Leach said this is one of the few projects of which the benefits are known immediately.

"The evening it opened, people were clamoring to use it. It proved what we had imagined all along - that it was needed for the Alton area," he said. "The old truss bridge served its purpose, but it was just outdated."

The new bridge opened in January 1994, and the lights were added some time after that in the spring.

Leach said the project incurred very few problems overall. The biggest one, the flood of 1993, could have been much more troublesome if it had occurred earlier in the process.

"Most of the work, by then, was confined to the deck so we were above it," Leach said. "There was still some difficulty getting materials to the site. We did have some difficulties when several people, at different times, threatened to jump off the old bridge. Fortunately, nobody did."

Leach said the contractors were very good, and the fact that no one was killed on the project is a testament to that.

"It took quite a bit of effort to make sure the job was a safe project. That's really what's important," he said.

Leach said he really doesn't think Alton has seen the total benefit of the Clark Bridge yet.

"I think we will continue to see it help this area grow again, combined with the effect of Interstate 255," he said. "It was a replacement bridge, not a new bridge, but it was a tremendous improvement and made a big difference. We were also proud of the cost."

In comparison to other bridges, the fact that the Clark Bridge was completed for $113 million is reasonable, he said.

"It's actually a very economical structure," Leach said.

Jack Blakemore, also with Crawford, Murphy & Tilly, was a new engineer at the time the bridge was built and he was thrilled to be given the opportunity to work on such a large, high-profile project.

"Something like that just doesn't come along every day," Blakemore said.

"I remember the weather caused some problems," he said. "During the flood it was harder to keep things secure, but with a normal pool, things went pretty smoothly.

Several factors pointed the way to the choice of a cable-stayed bridge, as opposed to a truss, tide arch or suspension bridge. A traditional bridge requires a pier every so many feet; the cable-stayed span can span a greater distance and is more conducive to heavy river traffic. The cable-stayed is also relatively lower in cost than the truss, and the tide arch would have required temporary construction that could have slowed river traffic during the construction phase.

The U.S. Coast Guard wanted a bridge design that minimized the disturbance of the barge traffic.

"Of course, since the bridge has some of the substructure in the river, it was necessary for it to be designed to resist ice loads and barge impact forces, in addition to the normal loads for a structure of this type," said Steve Putz, senior design squad leader and senior resident engineer with the Illinois Department of Transportation.

Some of the unexpected issues that arose during design, he said, included the need to design elevated footings on the Missouri side to eliminate costly deep-water foundations.

"No one ever expected to uncover remnants of an old side-wheeler boat on the Missouri approach," he said. "That discovery delayed the contractor for a while. The old sunken barges that the scrap company on the Illinois shore had buried, to use as a ramp for its operations, also delayed the Illinois approach contractor. But constructing any structure in the river involves risk and normal obstacles.

"The river aided the project, in that the piling for the foundations and the pre-cast panels for the main span superstructure were delivered by barge," he said.

Many companies and individuals played major roles in the construction of the Clark Bridge. Hanson Professional Services Inc. was the lead designer. Figg Engineering Group was a sub-consultant to Hanson. Midwest Foundation Corp. built the main span foundations, McCarthy Brothers Co. and PCL Construction Enterprises Inc. built the main span superstructure; Massman Construction Co. and Ben Hur Constructors Inc. were the Missouri approach contractors; Keller Construction Inc. and Gencon Inc. were the Illinois approach contractors. The lighting contractor was Wissehr Electric Inc., the signing contractor was TMR Construction Co. and the demolition contractor for the old bridge was Anderson Excavating and Wrecking Co.

The old bridge was demolished with the use of charges to cut the members into pieces; the old substructure was demolished by use of drilled and placed charges to fracture the concrete so that everything could be easily removed from the river, Putz said.

"The Clark Bridge has won numerous awards for its special design," Putz said. "There were several innovative design 'firsts.' The most significant was the use of a single pylon with two planes of cable stays."

Some of the awards the bridge has received are; first place for long-span bridges in 1996 in the American Institute of Steel Construction Bridge Competition; the Quality Concrete Award from the Concrete Council in 1995; it was voted one of the 12 best bridges in America by the American Consulting Engineers Council in 1995; Most Innovative Structure Award in 1994 from Structural Engineers Association of Illinois and the 1994 Project of the Year from the American Society of Civil Engineers, St. Louis Chapter.

IDOT is the leading state agency overseeing maintenance of the bridge; the cost for maintaining Clark Bridge is shared between Illinois and Missouri.