ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/532296
PROJECT I-84 Bridges over Marion Avenue An accelerated bridge construction success story in Southington, Conn. by Andrew Lessard, Stantec For the last few years, state transportation departments across the country have begun using accelerated bridge construction (ABC) to minimize the sometimes-lengthy disruption to the driving public that large construction projects can have. In 2014, the Connecticut Department of Transportation (CTDOT) realized it had an ideal opportunity to employ ABC on a large-scale construction project: the reconstruction of two structurally deficient highway bridges along Interstate 84 (I-84) in Southington, Conn. The resulting effort reconstructed the two heavily traveled bridges in just a single weekend, avoiding what would have been months—or even years—of construction and associated disruption to traffic. The Marion Avenue Bridges The two bridges, which run parallel to each other on the eastbound and westbound sides of I-84, were built in 1963 and each carry three lanes of traffic over Marion Avenue. The bridges consisted of a similar cross section but slightly different span lengths. In 2008, the state identified the bridges as structurally deficient due to a deteriorating superstructure and moved them into a priority position for reconstruction. After determining that the substructure was still in good condition and suitable for reuse, the preferred scope of rehabilitation was to reuse the existing concrete abutments and bridge seats. A design plan was developed based on New England bulb-tree (NEBT) 1200 prestressed concrete beams supporting a cast-in-place concrete deck. As the team got further into design, however, CTDOT began exploring the idea of using an ABC approach to reconstruct the bridges and minimize the significant impact that this type of project would have on traffic. The I-84 Bridges over Marion Avenue project stood out as a good candidate for ABC thanks to two main factors: schedule and site. Schedule Because all three lanes of traffic in each direction of I-84 would need to stay open during construction, traffic congestion became a major concern. With conventional construction, accommodating that requirement would have entailed an overbuild of the bridges and widening of the existing abutments through four stages of construction. Each stage would have been months long, with significant adverse effects to I-84. With ABC, that duration would be condensed into the period of a few days. Site The bridges comprise the overpass component associated with a diamond interchange, meaning it would be relatively simple to route traffic around construction using the interchange off and on-ramps. This also meant that there was a large work area for the contractor to construct the new bridges offline with no impacts to mainline traffic. Profile I-84 BRIDGES OVER MARION AVENUE / SOUTHINGTON, CONNECTICUT OWNER’S LIAISON ENGINEER: Close, Jensen and Miller P.C., Wethersfield, Conn. BRIDGE DESIGN ENGINEER: Stantec Consulting Services Inc., New Haven, Conn. PRIME CONTRACTOR: Northern Construction Service LLC, Weymouth and Palmer, Mass. HEAVY LIFT CONTRACTOR: Marino Crane/Barnhart Northeast Inc., Middletown, Conn. PRECAST BEAM DESIGN: Eriksson Technologies, Tampa, Fla. CONTRACTOR ENGINEERING: Steere Engineering Inc., Warwick, R.I.