Silver Spring Transit Center report details problems and solutions -- Gazette.Net


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This story has been corrected on March 27. An explanation follows.

Watered down concrete, flawed design and inadequate inspections are just three of the dozens of major problems with the design and build of the Silver Spring Transit Center, according to a report released March 19.

David Dise, director of the county’s Department of General Services, said the next step is to get everyone back working on the project and have a team of consultants and staff to engineer the suggested solutions. At the same time, his staff will read through the reports, doing a forensic analysis of the process to see where exactly things went wrong.

“We want it safe. We want it durable. We want one solution. We get one chance to fix this, so we want to know exactly what the problem was,” Dise said.

It appears the report may outline a plan to fix the center, but what is still unclear is how much it is going to cost.

Groundbreaking for the Silver Spring Transit Center — a $112 million transit hub project on the corner of Colesville Road and Wayne Avenue in downtown Silver Spring — was in 2008. The center was expected to open in 2011, but a series of cracks found in the structure and disparities in the thickness of the structure have delayed the project’s opening by nearly two years so far.

Montgomery County hired Washington, D.C.-based KCE Structural Engineers to study the structure. On Tuesday, the 100-page report was presented to the county council, stating that KCE and its team found serious problems with the design, construction, concrete strength, concrete testing accuracy and adherence to fire codes at the center.

“Once we found out that the concrete was not what we thought it was, that was the game changer as to what we needed to do next and how that would impact everything else,” Dise said.

The transit center is not just “another concrete parking garage,” Dise said of its complex design. In a transit center where buses with large, varying loads will be moving as opposed to parking, Dise said, it is important that the structure be rigid. The county chose to use concrete as opposed to steel because steel tends to flex more, he added.

Dise said the structure, as built, would only last 13 years due to structural damage and water damage. Without the KCE engineering report, safety issues would be unknown until a potentially dangerous incident occurred. The center is supposed to have a 50-year service life.

When KCE prepared its report, the county instructed the company to do a full analysis of the structure, including the thickness of the concrete slabs, visible evidence of extensive cracking in the slabs, beams and girders. Also, exposed post-tensioning ducts, which are­ used to hold tension wires in place, should have been covered with two inches of concrete.

KCE retained Wiss Janney Elstener Associates, Inc. and Walter P Moore and Associates, Inc., who also retained other consultants and subcontractors to evaluate the structure.

Design deficiencies

The report specified a number of design deficiency allegations against Parsons Brinckerhoff, Inc., the company hired to do the design, which has its corporate headquarters in New York. The report alleges the tension lines were incorrectly designed to be pulled too tight, stressing and causing cracks in the concrete.

KCE’s report also claims Parsons Brinckerhoff failed to incorporate certain Washington Metropolitan Area Transit Authority design criteria into contract documents; that expansion joints — which allow concrete to expand and contract with the weather — were inadequate in number and in placement; and that the concrete pouring and curing requirements were not incorporated into drawings and contract documents. The report also says Parsons Brinckerhoff failed to accommodate fire rating requirements.

Parsons Brinckerhoff did not return a request for comment on the findings of the report.

Construction deficiencies

KCE’s report also details construction deficiency allegations against Foulger-Pratt Cos. and its subcontractors, including slab thickness, which it states was well below contract requirements, and concrete strength.

The contract calls for concrete strength of 8,000 pounds per square inch (psi), but the report claims that Foulger-Pratt, through its subcontractors, provided concrete with a calculated strength of 6,970 psi.

In addition, the report alleges the concrete in five sections of the first and second levels have unacceptable concrete strength, and concrete sections on the third level do not contain post-tensioning cables or sufficient rebar to support design loads, which automatically makes the facility unusable, according to the report.

The concrete strength also is compromised by a combination of too much water in the concrete mix and improper cold curing methods to harden the concrete, according to KCE and its team.

Foulger-Pratt would not yet comment on the findings of the report.

In discussions with Foulger-Pratt prior to the report’s release, company Principal Bryant Foulger told The Gazette in January that the company was frustrated with county because it “failed to cooperate with Foulger-Pratt” and “continuously hindered the development and implementation of a timely and practical plan forward.”

Deputy County Attorney John Markovs said the county wanted to have all of the information it could gather independently to “check it all” before having a discussion on how to fix the facility.

“There was nothing to talk to them about because we didn’t know what the results were or what we were doing,” Patrick Lacefield, a spokesman for the county executive, said.

Dise said Foulger-Pratt was only one part of what turned out to be a series of major problems.

“Had we let this out in bits and pieces, everyone would’ve been nipping at those elements,” Dise said. “It was important instead that we do every extent of thorough investigation necessary, so we absolutely know what the problem is and how to fix it.”

Inspection deficiencies

The report also details inspection deficiency allegations against The Robert B. Balter Company of Owings Mills, hired by the county for inspection testing for the project.

The first allegation in the report was that the company’s inspections were not completed in accordance with the contract documents, WMATA standards or the Statement of Special Inspections by Montgomery County Department of Permitting Services. The second claimed the company failed to provide adequate inspections with respect to concrete placement during the curing and representative samples testing, which KCE believes contributed to concrete strength deficiencies.

Solutions

In addition to finding out what problems exist at the center, KCE and its team were tasked with providing a concept for the repairs so it could be safely put into operation. The recommendations included removing the concrete that is not properly reinforced, installing rebar and metal reinforcements, and repouring the concrete slabs.

The second fix is to repair concrete thickness in some areas where concrete is deficient and existing cracks needs to be repaired and properly sealed.

KCE provided two remediation methods to do that. One would require pouring concrete on top of the existing concrete slabs with waterproofing to prevent moisture from penetrating the structure. A second option would be to prepare the concrete slabs to bond by roughing them down and pouring concrete, so the surfaces fuse together chemically. Dise said the county has not yet determined which remediation method to use.

This is the first time the county has needed to have a report provided on a county project, Dise said. He said there is “no reason to be concerned about any of the other projects” in the county. Nine county projects will be opening this year alone, Dise said.

There are no current contracts with Brinkerhoff or Foulger-Pratt, however Balter is the county’s current inspections consultant.

Markovs said litigation is possible, but still undetermined.

“The county remains cautiously optimistic that the contractors that have been involved in this project are going to do the right thing and remedy the issues that they’ve caused with the transit center at their cost and expense and allow the project to move forward,” he said. “If they don’t fulfill their contractual obligations to the county then yes, litigation would be inevitable.”

krose@gazette.net

Editor’s Note: The date of the report’s release was corrected.