Walker OKs Hoan Bridge renovations

According to the Wisconsin Department of Transportation, supports on the Hoan Bridge continue to deteriorate. Tribune File Photo

If you plan on attending Summerfest, you might want to bring a hardhat.

Festival patrons might be in danger of falling concrete from deteriorating parapets of the nearby Hoan Bridge, according to a recent report done by engineering firm Graef-USA.

The bridge, which opened in 1977, is a vital avenue of transport that connects Milwaukee’s south side neighborhoods to downtown.

Graef-USA’s report, submitted to the Wisconsin Department of Transportation in January, says the decades-old bridge’s support systems are deteriorating. Additional problems include chipping paint, rusted girders and joints, and a worn-down concrete road surface above.

The report helped spur Gov. Scott Walker and the DOT to move forward a major renovation project to be started in late 2013. The $275 to $350 million project is expected to take three years, and was announced by Walker this month.

Although the report does not classify any of the failing systems as “emergency items,” the study was only a preliminary investigation. The firm will conduct a more extensive look into the structural health of the bridge, and the final report is due in June.

Christopher Foley, a professor of civil construction, has done research on wireless sensors that can be affixed to structures like bridges to remotely monitor structural health. Foley said there are corrosion and moisture sensor systems that might have caught the deterioration earlier.

“If (the sensors) were installed as part of a health monitoring system, it is likely that the factors leading to premature bridge deck deterioration could have been watched during the bridge’s service life,” Foley said. “This is being done on many new bridges, and the reconstruction of the Hoan’s deck that is going to happen now can benefit from installation of such sensors and a bridge deck health monitoring system.”

The Hoan Bridge was built before the sensor technology was developed.

Emlynn Grisar, communications manager for the DOT Southeast region, said the government body was aware of the report and the repairs needed. She also said there is no planned shutdown of the Hoan Bridge, and they are constantly monitoring the situation.

Neither Summerfest nor Graef-USA officials responded to interview requests by press time.

A main concern of deterioration was the chipping of concrete vertical supports that had worn down enough to expose the internal steel reinforcement. The report recommended barricades be constructed around deteriorating supports to prevent grounds workers from entering possibly hazardous areas.

Falling concrete from overhead sections of the bridge is no new danger for the marquee Milwaukee event that bills itself as “The World’s Largest Music Festival.” There have been two instances of such hazards, once in 1996 and again in 2010. Netting had been installed on both occasions, and appears to be functional, according to the Graef-USA report.

The planned large-scale renovations will surpass the emergency work done in 2000-’01 as the most extensive maintenance on the Hoan Bridge. Those repairs were undertaken after a fracture in support girders caused a southern portion of the bridge to buckle.

Planned renovations include a complete replacement of the bridge deck and concrete overlays. As for temporary fixes, work crews will be working throughout the summer to replace cracked sections of the bridge deck.