Mystic Transportation Center

Parking structure spandrel units that serve as exterior bumper guards and life-safety guardrails serve double duty and save construction costs. But by turning it into a load-bearing unit, the spandrel goes the extra mile to really become a money-saver. Such was the case with the Mystic Transportation Center in Medford, Mass., a Boston suburb. The garage stands at the center of the Mystic Center Office Park, which was master-planned in 1986 by Thomson Design Associates of Boston. Thomson Design also designed the new parking facility, which is complementary but not identical to the office buildings. The parking structure provides 1,389 spaces for workers in the nearby office park and for Boston commuters with easy access to the commuter station via an 800-foot-long people mover. The garage has a footprint of 256 by 180 feet and provides 410,000 square feet of parking space in its eight stories. It is considered phase one in a two-phase construction plan. A nearly identical structure, slightly smaller at 226 by 180 feet and with 1,200 parking spaces, is to be added. The eight-story building was planned so that standard 11-foot-wide double tees could be used throughout. Even the two elevator-stairway towers are placed outside the main structure, simplifying the construction process. The basic layout of the garage features an uninterrupted array of three 60-foot-wide bays in a combination of 33-foot and 43-foot lengths totaling 253 feet long. The center module is supported by a shear wall system that also provides lateral bracing.

Other Systems Considered

"Both precast and cast-in-place, post-tensioned concrete were considered," says Bill Wieners, director of marketing for Northeast Concrete Products LLC, the precast supplier. Precast's initial cost was less than other systems, he adds, partly because of the standardization in the construction of the precast components. "With the quality control that came with factory casting and the use of steel forms to construct precast components, including the spandrels, precast clearly was the optimum way to build." The advantages to using precast were fourfold, says architect Brian Thomson, president of Thomson Design. These were "fast erection time, economy, low maintenance and integration of a high-quality architectural finish in structural components that were used as the building's facades." The structure cost $12 million, with another $4 million allocated for the people mover, consisting of an 800-foot guideway and two vehicles, each with a capacity of 50 people. The vehicles are pulled by cables linked to a motor, "like an elevator, except it's horizontal," according to Thomson. It links the garage with the Wellington Orange Line Rapid Transit station of the Massachusetts Bay Transportation Authority (MBTA).


Project Details


15 Presidents Landing






Thomas Design Associates of Boston


• The Consulting Engineers Group
• McNamara/Salvia, Inc.


Suffolk Construction Company, Inc.

Sq. Footage:

410,000 sf


8, 1,389 cars

Structural Precast Elements:

• 861 total precast peices
• 40 columns
• 541 11-ft wide double tees
• 60 12" lite walls
• 50 12" shear walls
• 81 spandrels (load bearing)
• 22 spandrels (non-load bearing)
• 67 double and single ledge beams


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