DOVER, Del. (AP) — A contractor dumped a mountain of dirt about two stories high and 100 yards long next to an interstate bridge over several years, so much that it may have moved the ground and caused the bridge to tilt, state officials said Wednesday.
The Interstate 495 bridge, a major East Coast thoroughfare traveled by 90,000 vehicles daily, was closed Monday when engineers determined that bridge support columns were leaning. Officials aren't sure when the bridge will reopen to traffic.
The contractor, James Thomas Jr., said he was working with state officials to remove the dirt from the site, which he was allowed to use under an arrangement with a company that leases land. Dump trucks removed dirt Wednesday for a third day.
Engineers suspect the weight of the dirt caused the ground underneath the bridge to shift. Four pairs of the bridge's support columns were tilting toward the pile of dirt.
"I really feel bad about what happened," said Thomas, 60. "I have absolutely no idea what happened, I really don't. ... I'm not a structural engineer. I'm not a bridge engineer."
The DuPont Co. owns the land where the mountain of dirt is located and leases it out to a materials handing company called Port Contractors Inc., which in turn, has an arrangement for Thomas to store dirt on the site.
Experts were still trying to determine exactly how big the pile of dirt was. The bridge will remain closed until engineers figure out how to brace it and make it safe.
"I think anybody with an engineering background would look at that and say, 'Here's your problem; this is something you need to deal with immediately,'" said Delaware Transportation Secretary Shailen Bhatt.
He said transportation officials did not know about the dirt mound until Monday, when engineers visited the bridge in response to a report received late last week. That report came from an engineer with a private company who was in the area on an unrelated project and saw cracking in the soil around the dirt pile. The engineer then spotted the leaning columns and contacted the transportation agency.
Officials said they were examining aerial photographs in an effort to ascertain how long the dirt mound has been there.
"In 2012, there was some stuff out there but not very much; in 2013, a little more," Bhatt said. "Right now obviously there's a lot more dirt under there."