Mayor Chris Beutler, Chair of the West Haymarket Joint Public Agency (JPA), today announced that corrective action will continue over the next two months on about half of the 52 pile caps that have been built for the new Pinnacle Bank Arena. Structural engineers have completed designs for that corrective work following the discovery in December of improperly fabricated reinforcing steel or "rebar" being used in the construction.
"The corrective work has begun and will take place over the next two months, concurrent with the overall construction schedule," Mayor Beutler said. "We also have an enhanced rebar inspection process in place that will ensure that this problem will not reoccur. The team is back on track to complete the project on time in September of 2013."
The Pinnacle Bank Arena is being built by Mortenson Construction-Hampton Enterprises.
Construction was suspended by Mortenson-Hampton December 20 when a several bars supplied by Drake-Williams of Omaha broke during installation. After close inspection of all the rebar material on site, the design and construction team determined that some bars were improperly bent in the fabrication shop. Extensive laboratory testing determined that the quality of rebar material itself met all of the specifications, and the issue was limited to improper bending of the bars. Work resumed December 27 when replacement rebar was delivered.
Pile caps are large concrete bases that are constructed above the deep pile foundations and transfer the load of the structure above to the piles The structural engineering team of DLR and Buro Happold has determined that a number of the pile caps that had been constructed with the improperly bent rebar needed corrective work.
"We've utilized a conservative approach to engineering analysis, analyzing each component, and we've determined that corrective work is required on 26 of the 52 pile caps already constructed at the time the issue was discovered," said Matt Farber, Structural Engineer at DLR Group.
"As a design and construction team, we've taken every step possible to ensure that we found the root cause of the issue and we've worked with the design team and experts to develop a conservative approach that will result in no compromise to the arena structure and no repeat of the problem," said Derek Cunz, Vice President of Mortenson's Sports Group. "This issue will not delay the completion of the arena or cause any increase in the value of our contract with the JPA."
The rebar inspection process has been enhanced to include the measuring of bend diameters to ensure that rebar has been bent in accordance with design specifications. This practice is not normally used on construction sites. Both Mortenson and Terracon, the JPA's Special Inspector, use a special template when inspecting rebar. In addition, rebar also is marked with spray paint at different intervals of the overall inspection process to insure that only inspected rebar is used on the site.