By Lisa Capobianco
The Connecticut Department of Transportation (DOT) has created a design plan to replace the bridges carrying I-84 East and West over Marion Avenue in Southington.
Built in 1963, each bridge carries three lanes of traffic, and the average daily traffic (ADT) was reported to be 81,800 vehicles as of 2012, according to ConnDOT.
ConnDOT reported various reasons for the rehabilitation project, including diagonal cracks as well as exposed reinforcement and tendons. ConnDOT reported that the bridge received a superstructure rating of 4 (on a scale of zero to nine). The rating, which considers the superstructures to be structurally deficient, is based on the National Bridge Inventory (NBI) General Conditions Ratings.
According to the NBI manual, bridges that are structurally deficient may be in poor condition due to deterioration or damage. Since the superstructures were found to be structurally deficient, the bridge will not be entirely replaced. A superstructure is a portion of the bridge (similar to a deck) that primarily supports traffic loads, reported Transportation Engineer Mary Baker of ConnDOT.
Baker said the project promotes commerce as it will enhance the safety of the superstructures.
“It will be able to maintain all the traffic loads,” Baker said. “It won’t continue to deteriorate.”
The existing superstructures will be replaced using Self Propelled Motorized Transporters (SPMT), platform vehicles that have the ability to carry large structures such as bridges from offsite locations into different positions. These transporters will move prefabricated superstructures from staging areas to replace the current superstructures. Once the existing bridges are removed, the new structures will be set into place. Northern Construction Service, LLC, is the contractor of the project.
Although an exact date has not been set yet, the replacement will entail a 56 hour maximum closure of I-84 eastbound and westbound at Exit 30 and Marion Avenue. The closure will take place during a weekend in the beginning of summer (expected in or around June), and traffic will be maintained using various detours.
According to the DOT’s project plan, traffic on I-84 Eastbound will be detoured along I-691, I-91, Route 9 and Route 72. Traffic on I-84 Westbound will be detoured along Route 9, I-91 and I-691. DOT also reported that the entry to Marion Avenue will be closed, and one lane of I-84 east and westbound traffic will remain open along the ramps.
During the weekend work, Marion Avenue under the bridges will be closed, and local traffic will be detoured along Diana Road, Prospect Street and West Street.
Officials from CT DOT said the project entails using Accelerated Bridge Construction (ABC) methods to reduce construction time and inconvenience for drivers.
“We are going to do our best to make the bypass flow and minimize the inconvenience, but they have to realize if they have an alternate way, they should think about it,” said Transportation Supervising Engineer Terri Thompson, adding that DOT is planning a public information meeting for the community some time in the spring.