BRIDGE RESCUE: DelDOT comes up with a game plan for I-495 bridge

Following 60 hours of continuous monitoring of the I-495 bridge that was closed Monday due to a shift in four support piers, DelDOT announced on June 5 that no additional, significant movement of the structure had been detected.  

The department’s goal is to open the road as quickly and safely as possible. To do so, the department has developed and has begun following a multistep plan:

• The department will complete the inspection of the remaining piers and continue the subsurface investigation including soil borings;
• Agency consultants are actively reviewing design options to create a new foundation for the damaged section of the bridge;
• The footer and the top of the underground piles for pier 12E have been exposed and no corrosion was present. This makes the department more confident that the problem is isolated to the four piers that are known to have shifted;
• Because a crack was discovered in the footer of pier 12E, which is consistent with the lateral displacement of soil, the department will be uncovering the rest of the footers of the affected piers to inspect them to determine if further damage has occurred;
• The University of Delaware will continue to provide assistance and support to DelDOT and will review findings and proposed solutions. They have concurred that DelDOT and the consultant’s assessment of the situation is accurate;
• The dirt that was located near the bridge is being removed by the contractor and crews from DelDOT;
• The tilt monitors that have been in place for the past few days will remain in place throughout the duration of the event;
• The department will continue to work with the city of Wilmington and our regional partners on traffic mitigation efforts;
• A field office to staff the ongoing work at the bridge site will be set up on Friday, June 6; and 
• Gov. Jack Markell signed a Declaration of Limited State of Emergency in connection with a request for Federal Relief Funds from the Federal Highway Administration.

Delaware Transportation Secretary Shailen Bhatt said, "DelDOT understands that there’s an urgent desire to open I-495, but public safety must remain our No. 1 priority as we systematically go through the steps and series of options needed to reopen the bridge. We know at this point that we are not looking at an event measured in days or in years. This will be an event lasting weeks and perhaps months."

In view of what has occurred, Bhatt said the department has developed a prioritized list of similar bridges (piers/columns, soil type, etc.) starting with interstate bridges, that engineers began inspecting to determine if there are materials or equipment stored too closely and whether or not right-of-way fencing is in place.