30 August 2011
This short film explains the process by which consultant Modjeski & Masters helped Louisiana Department of Transportation & Development with the replacement of the entire I-20 overpass superstructure using one of the first applications of accelerated construction method for this client.
When the Well Road overpass was constructed in the 1960s, it was designed to carry minimal traffic in a fairly rural area of Louisiana. But with urban expansion, traffic in the area has steadily increased until a replacement of this vital thoroughfare was necessary in order to safely carry the increased loads.
The LADOTD appointed Modjeski & Masters to help design a replacement for the overpass. M&M provided preliminary and final design services for the replacement of the entire I-20 overpass superstructure using accelerated construction methods.
To eliminate long-term construction and closures on the overpass, the solution resulted in an abbreviated construction phase of just a single weekend. This included the erection of new replacement spans on-site at a staging area within the interchange. In addition, substructure units were strengthened while the existing superstructure remained opened to traffic.
Self-propelled modular transporters then were used to remove the old spans and roll-in the new spans. During the weekend lane closure period, interstate traffic was routed through the interchange exit and entrance ramps. M&M also provided traffic control plans, special provisions, and LRFR rating of the structure.
This was the first time that SPMTs were specified during the design of a bridge replacement project for the Louisiana Department of Transportation & Development.The project was successfully completed one day ahead of schedule.
Modjeski & Masters