Wall failure delays bridge project: Maguire contractor, city disagree on liability
The heavy rains on Aug. 20 undermined the foundation under one of the rock-basket walls holding the Maguire Boulevard bridge over Grindstone Creek and caused the wall to fail, according to documents obtained from the Columbia Public Works Department.
The city, its contractor and consultants agreed on a repair solution Oct. 12. The bridge could be ready to open to traffic by early November, Assistant Public Works Director David Nichols said. The city had planned to finish construction by Oct. 1.
“It was a huge, huge sigh of relief,” Nichols said.
The $8 million Maguire extension has been a long time coming. LeMone Industrial Park suffers from traffic congestion because it can only be entered from the southern end via New Haven Road. With hundreds more people expected to begin work at the new IBM center in coming months, the extension to Stadium Boulevard will be a critical point of northern access to the industrial park. City Manager Bill Watkins has indicated that without the extension, the IBM deal might not have been possible.
The city and the general contractor for the road project, Emery Sapp & Sons, spent a month looking for a solution that didn’t require tearing down large portions of the bridge and starting over. Nichols stressed that the situation could have been much worse.
“At one point we thought we were going to have to start all over and tear the wall down,” he said.
But one issue still remains: assigning responsibility for the wall failure. Emery Sapp & Sons and the city disagree on who should pick up the tab for the extra work to fix the bridge.
Documents obtained from Public Works indicate that Emery Sapp & Sons believes it should not be liable because of bridge design “short comings,” city building directives and the heavy rainfall that night. Jason Rode, the contractor’s project manager, referred to the rain as “acts of nature in excess of city design standards.”
The city points to its official Standards and Specifications, which says that until work is accepted by the city engineer, the contractor is responsible for any repairs. In addition, the city and some of its engineering consultants said the contractor did not properly perform some of the construction work near the failed wall.
Emery Sapp & Sons did not return phone calls seeking comment.
Both sides agreed to finish the project first and then deal with the liability issue, according to Nichols and references in the documents. However, the cost to whichever side ends up paying for the extra work will be “a fraction” of what it could have been if the repair agreement had not been reached last week, Nichols said.
The wall failure is the latest bump in a road project that has been filled with controversy. In June 2008, the City Council voted 4-3 to approve the road and bridge construction, with opponents citing the environmental risk to Grindstone Creek.
Developers of the planned Crosscreek Center, Stadium 63 Properties, previously angered environmentalists and some city officials by removing the trees and grading the areas above Grindstone Creek where the bridge was destined to cross.
The lack of vegetation, storm water runoff from adjacent property owned by Ameren UE and the road project itself have exacerbated soil erosion into the creek.
Some members of the City Council visited the site in May 2009 and expressed concern about erosion into Grindstone Creek. The Missouri Department of Natural Resources sent an inspector to the site a month later after a citizen raised similar concerns. At the time, the inspector, Matt Sperry, noted some issues with erosion control but said, “It could have been a lot worse.”
The bridge, however, was designed to minimize storm water impact and its footprint on the stream bed, Nichols said.
The walls parallel with the creek are vertical rather than sloped toward the creek. The bridge walls are built with baskets filled with rocks rather than solid concrete. The porous structure allows water to trickle through to slow storm water runoff. There are also devices that filter sediment and impurities flowing from the road before letting the water trickle into the creek.
But the novel design might be one of the reasons the bridge has faced problems. Columbia has not built a bridge using the environmentally friendly design features before.
One of the design features that led to the wall failure was a water filtration device. Emery Sapp & Sons maintains that one of the main factors in the wall failure was the location of the storm drain, which washed water beneath the wall during the heavy rain. The contractor and one of the city’s engineering consultants recommend redesigning the feature to direct rain water away from the bridge so it conforms to typical industry practice, according to the documents.
Nichols said the city will likely redesign the storm drain to redirect storm water flow. However, he said the contractor left the drain only half constructed when the heavy rainfall hit that Friday evening. Filtration devices that would have slowed the water flow were not installed, which led to the heavy volume that damaged the wall.
Engineering consultant Affinis Corp. also noted that some portions of the wall were not properly constructed, according to the documents.
In looking for a solution, the city and its consultants had to make sure whatever repair was made to the wall did not adversely affect other components of the bridge, and reaching consensus caused much of the delay.
“There was no way we were going to do anything without all of our engineers signing off on the design plan,” Nichols said.
The solution, agreed to by the city Oct. 12, calls for workers to fill the void underneath the wall with concrete grout and build a stabilizing buttress to the side of the wall, Nichols said. Although there were questions at first about whether the plan would stabilize the wall, all parties seem to agree it is a viable solution, according to the documents, and the long awaited road should soon be ready.
“There are people who’ve been waiting 20 years for this thing,” Nichols said.
Neither the city nor Emery Sapp & Sons provided an estimate for the construction cost increase, and the question of liability for the failure has yet to play out.
“I can’t see it as big of an issue after the (Oct. 7) meeting as it could have been,” Nichols said.