Work has begun on a mammoth and innovative expansion of the parking structure at Logan International Airport in Boston. The new facility will add three levels of parking above the four existing floors without closing the structure to users during construction. The design features a total-precast concrete structure that was value-engineered from a steel and cast-in-place design to save both time and money. The precast components are being produced by Blakeslee Prestress Inc. in Branford, Conn
The project encompasses three distinct activities. The "underbuild" portion will revamp the first two levels of the existing four-story structure. The "overbuild" segment will add three levels above the existing levels. And the entire structure will be enclosed in a new precast concrete façade that includes an H-frame system to handle the load of the new upper levels.
The project, which is owned by MassPort, is being designed by Parsons, Brinkerhoff, Quade & Douglas for the new sections. Engineering on the repairs and foundation is being performed by Fay, Spoffard & Thorndike, while Zaldastani Associates Inc. is doing repairs on the two levels of parking. Turner Construction Co. is serving as construction manager, and TAMS c/o Fennick/McCredie Architecture Ltd. is the architect.
The precast concrete team, led by Blakeslee, also includes Helm Wilden Associates as precast specialty engineer. The components are being erected by Precast Erectors Inc. and Marino Crane Service Inc. Erection began this summer, and construction is expected to be completed in the summer of 2007.
For the underbuild portion, specially designed erection equipment allows the 55-foot-long double tees to be erected beneath the existing third level, which will remain in place after the first and second floors are demolished. On the overbuild portion, precast concrete columns will be dropped through the existing four-level structure to support two gantry craneways built above the existing structure. This approach will reduce risk and speed up construction with the use of two 600-ton-capacity DeMag cranes on top of the craneways.
The project features a number of challenges, including the tight airport site, which encompasses the airport control tower within the footprint of the existing parking structure. Blakeslee will be casting more than 5,200 precast components, including double tees, girders, columns, frames, spandrels, stairs and wall panels. |