Arsenal Yards is a new one-million square feet, mixed-use development in Watertown, Massachusetts. It will include apartments, shops, restaurants, a movie theatre, and a Hampton Inn hotel. Construction began in 2017, and the entire project is expected to be completed by 2021.
Developers Boylston Properties and the Wilder Companies are behind this redevelopment and expansion of the former Arsenal Mall site in Watertown. Prellwitz Chilinski Associates is handling the design and Cranshaw the construction of the project. The first phase includes the construction of the hotel and garage, along with some retail tenants, all scheduled to open in the Fall of 2019.
The Watertown Arsenal, established in 1816 by the U.S. Army as an ordnance depot and small arms factory, served multiple functions over the years and closed in 1968. The complex was converted into the Arsenal Mall in the early 1980s.
“PCA is the base building architect and was involved in creating the master plan and overall design aesthetic. Our main focus was to highlight the two existing buildings of the Arsenal. The other structures complement and highlight but do not replicate it. The precast on the garage was a great contrast to the old brick and we wanted to find ways to aesthetically integrate that into the project,” explains Laura Portney, Senior Associate, Prellwitz Chilinski Associates (PCA), Cambridge, MA.
The new parking garage will be adjacent to the Hampton inn. “With safety as a primary concern it was important that we created a safe, well-lit garage,” explains Portney. “We did a study at the beginning of this job and toured a number of projects to determine the best use of precast, which is becoming more prevalent in this area. The goal was to make it feel bright and open as well as aesthetically pleasing. Working with Blakeslee Prestress we were able to maximize the use of precast on this garage,” recalls Portney.
“We worked with Blakeslee to create the right colors and textures and went to the plant to review mockups of the selected patterns. We had researched formliners that we liked and we created a model with SketchUp to understand spacing and variations in the casting. At that time we also reviewed the depth of sand blasting. It was great to be able to do that in real time at the plant to achieve the right exposure of aggregate and the desired aesthetic,” explains Portney.
“Precast garages are becoming more popular in this area”, says Jack A. Wood P.E., Associate Principle, Veitas & Veitas Engineers, Braintree, MA. “For this project, they specified a much higher grade spandrel panels than you would typically see on a garage,” says Wood. The precast features a formliner to create shadow lines across the façade of the garage. This is in keeping with the increased emphasis on aesthetics as parking structures are often the first impression of customers to a mixed use destination.
On the first level – the precast structure had to accommodate truck loading. “We couldn’t use the typical double tees on the first level where trucks needed access. Precast NEXT beams were used in that area to support the additional loading. That was the only access for delivery to retail in the rear of the garage. In order to ensure trucks did not enter the rest of the garage, crash bars were installed to deter them from going any further up the ramp. “We designed the crash bars with bolted connections for quick replacement in the event of an accident,” explains Wood.
“This garage is a bit unusual in that the owner asked us to consider adding three levels of residential on top of the garage. Veitas & Veitas Engineers generated a model and provided Blakeslee the weight requirements to handle the additional gravity and lateral loads,” recalls Wood. The plan for future expansion also created some foundation issues in one area of the site and required a change from spread footings to piles due to unsuitable soils. The structure can now handle the possibility of apartments built above Garage B.
“Blakeslee partnered with us and coordination went very smoothly. During the design process there were a number of coordination reviews for critical items such as column pier location and elevation, precast double tee pockets, and shelf location and elevation,” says Wood. As a result there were fewer issues in the field during the winter 2019 installation.
The lower level parking is designated for the residential building that connects to this garage. The upper levels are for retail customers and the Hampton Inn guests.
“There was very little lay down area and not much room for the footings in the exterior wall. Project support of excavation (SOE) was extremely close and so exterior walls did not utilize typical retaining wall footings because of that. The limited space for footings was due to the requirement for road access at all times,” says Wood.
Phasing of construction was one of the more complicated aspects. There were many reasons the work needed to be staged, one of them being that existing retailers are open during construction, so the site needed to be accessible and safe for customers. It made more sense to construct and open the new parking garage prior to demolishing old surface lots.
“One of the reasons we really wanted to go with precast was due to the tight site and time constraints especially with winter construction,” says Portney. The ability to erect the entire garage in a tight site during the winter months was a benefit. Precast erection started in January, 2019 and completed in March 2019.
There are tenants that are open during construction which adds precautionary factors to an already congested site. Whenever you introduce the public to a busy site, there are always more challenges. “It is like a game of Tetris across the entire development as buildings come on line,” jokes Portney.
The new precast parking garage is a welcome anchor to the Arsenal Project for several reasons. “From a cost stand point it was more economical and the speed of construction was just another driving factor in our decision to erect an entire garage in a short amount of time,” says Portney.