Located adjacent to the Merrimack River in Lawrence, Mass., the Riverwalk Innovation District is a multifaceted real estate development effort that has reinvigorated a historic area. Today, through the work of Lupoli Companies, the campus is bustling with a mix of commercial, office, and residential properties. The Pavilion at Riverwalk is an 80,000-square-foot mixed-use structure, which consists of an elevated, regulation-size football field sitting atop a three-story precast concrete parking garage - offering a place of connection for the district’s visitors, tenants, and residents. The Pavilion serves as an ideal space to hold events and host sporting tournaments, all supported by the 1200-vehicle parking garage constructed with nearly 1000 pieces of precast concrete.
A Boom for the Community
The Pavilion at Riverwalk was designed to satisfy several goals. A high-capacity parking garage was needed at the location to accommodate the increased number of vehicles associated with the district’s new commercial and medical enterprises. The client on this project also wanted to give back to the community by incorporating a high-performing sports complex as part of the development, and it was important that the Pavilion offer opportunities for retail, restaurant, and office spaces as part of the master plan for the development campus. Ultimately, to meet these needs, the project team, which included PCI-certified precast concrete producer Dailey Precast LLC, of Shaftsbury, Vt., and architect SGA of Boston, Mass., selected to construct an all-precast-concrete parking structure. Dailey Precast, LLC manufactured 323,000 square-feet of precast concrete for this project.
“Precast concrete was the logical choice for such a large parking structure, but that choice was initially not so clear relating to the sports field on top,” said Mark Aho, PE, principal with McNamara Salvia Structural Engineers. “We studied both composite steel and precast concrete options for structural efficiency, constructability, and vibration performance. A driving factor in the design was stiffness of the roof structure to avoid any bounce that the athletes might feel while running on the field.”
By using one extra double tee per bay—or four 9-ft-wide tees— and adding a cast-in-place concrete topping slab, the team was able to achieve outstanding vibration performance for the roof structure. Additionally, the use of precast concrete tees allowed the roof structure to be erected in sequence, as opposed to the need to swing steel and metal decks after completion of the precast concrete parking levels. With the tight clearances around the project footprint, setting up another crane that would have the capacity and reach to erect an entire level of steel framing for the field would not have been feasible. Plus, because the precast concrete structure is durable and does not require painting, the parking structure will be relatively maintenance free over the long term.
For the field sitting on top of the Pavilion, an innovative underlayment system was installed that allows for proper drainage and the cushioning required for a high-performance sports surface. The project team took special care to ensure that the field goals and netting posts at both ends of the field were safely anchored into the structure. And although the parking levels are sloped to drain in a traditional alternating bay high/low pattern, this approach could not be taken with the field. The rectangular field is “crowned” so that the center of the field is about 18 in. higher than the sidelines, thus allowing for the playing surface to drain properly. To make this drainage possible, the field was centered on a precast concrete girder line to set the high point of the crown, with the double tees sloped down at a constant angle to the edges of the garage. As a result, the top level had to be 1 ft, 10 in. taller than the typical levels to allow for proper headroom clearance on the parking level below.
An innovative precast concrete system, combined with smart planning for the future, is what makes the Pavilion at Riverwalk so critical to continued development in the area. “Serving as the focal point of a large riverfront innovation district, this new building at the heart of the campus provides a place for tenants and local residents to gather, work, and play,” said Scott Barnholt, AIA, director of architecture at SGA. “This unique project further invigorates a historic campus that was once home to iconic mill manufacturers with new entertainment, commercial, and sports uses.”
Mason Nichols is a Grand Rapids, Mich.-based writer and editor who has covered the precast concrete industry since 2013.