The opening of the Silver Spring Transit Center, under construction since 2008, has been delayed yet again as Montgomery County officials study what is causing cracks in the structure.

The $112 million project originally was slated to open in summer 2011. Then it was postponed to November 2011, January 2012 and this summer. But the three-story facility, built to hold bus bays, a kiss and ride and a taxi stand and offer access to MARC, Metrorail and Purple Line trains, remains an empty concrete mass in downtown Silver Spring.

The structure was put on hold after the county discovered cracks in the concrete on large sections of the second and third levels, where the buses, kiss and ride, and taxis will be. About 63 percent of the concrete on those floors is either too thick or too thin, and in several places the steel supports are unprotected from weather erosion, an analysis by county-hired engineering consultant Parsons Brinckerhoff found.

The county and general contractor Foulger Pratt have been in discussions about how to fix the problem -- Foulger Pratt suggested a spray-on sealant, while the county talked about more drastic measures -- and who should foot the bill for the delays. Both sides hired consultants to study what needs to be done, and a third consultant was brought in to help settle the differences.

County Department of General Services Director David Dise had planned to brief County Executive Ike Leggett on the latest plans for the facility on Monday, but one more study is needed before a decision can be made, Dise said.

The new study, which Dise expects to take about four days, will "determine the extent of the cracking and whether there are any ... cracks that are in the concrete but haven't surfaced yet," he said. It also will help determine the cause of the cracks -- whether it's related to construction, design, weather or materials -- and help ensure that the county fixes the problem for good.

After getting the results of the study, Dise expects to brief Leggett in two weeks before discussing the matter with Foulger Pratt Principal Bryant Foulger. Foulger could not be reached for comment.

"We're still pushing to have this, whatever we do, done before the cold weather sets in," Dise said. Though he would not commit to an opening date, he suggested the possibility of opening parts of the facility while continuing to repair others.

Meanwhile, residents are tired of waiting for answers and have been flooding county lawmakers with requests for information.

"We understand they don't have an answer, but we also don't know what's going on behind the curtain," said Tina Slater, president of the Action Committee for Transit, which has been leading the charge for information. "I feel like we're being held at arm's length like we're children."