Completed by Walters Group earlier this year, 10 World Trade is a 17-storey, 555,000-square-foot building, located in Boston’s rapidly developing Seaport District. This project is a remarkable example of blending complex structural engineering with architectural design.
Nestled on a compact parcel of land, it is surrounded by the on- and off-ramps of I-90 and a transit tunnel running beneath it, leaving limited space for construction. The site allowed just enough room for a concrete core and four corner foundations. The narrow site and proximity to major traffic routes made traditional construction methods impractical. To address these constraints, Walters Group installed protective decks at lower levels of the building to protect traffic and existing infrastructure during ongoing construction.
BOSS Steel erected the entire project, including both the bridge connecting to the triangular building on the west side of 10 World Trade and the protection deck. The deck cantilevered over the intersection, demonstrating how the building would slope at the roofline. In addition to the outward slope, all four sides of the building were also curved. To achieve the concave edges, Walters Group shop fabricated and installed curved bent plates with curtainwall notches, meeting the tight tolerances required for the curtainwall.
However, the heart of the structure designed by Sasaki, and engineered by Thornton Tomasetti was focused at the base of the building. The large arches, ranging from 100 to 160 ft in length and made from 2.5 to 4-inch thick steel plates, had neither a consistent cross-section nor a consistent radius, and the truss above the arches introduced numerous complicated connections. To support these connections, internal stiffeners were used to reinforce the arches against the loads caused by the trusses. All arches were pre-assembled before delivery to ensure precise alignment, with assemblies weighing up to 150,000 pounds set to within a quarter-inch tolerance. The arches were erected on 200 tons of temporary posts and shoring towers, which were carefully removed after the arches and their trusses were fully installed.
Additionally, Walters Group fabricated the eyebrow canopies for each of the four arches. The canopies were curved to match the arches, with outriggers connecting the canopy frames to the arches at an angle. Due to the varying curvature and angled connections, extensive detailing and coordination were needed to ensure the canopies met architectural requirements.
Inside the building, the integration of complex geometric elements, including tight angles, heavy horizontal bracing, curved hollow structural steel (HSS), and a grand staircase with spiral curved plates, continued to pose challenges for Walters Group. With limited space on-site, we utilized just-in-time (JIT) deliveries to ensure the project was completed within the designated timeframe without disrupting ongoing construction. Walters’ precise sequence and logistics planning were critical to the project’s successful completion, ensuring everything stayed on schedule and operated seamlessly.
With the steel framework in place, representatives from Walters Group, Boston Global Investors, Suffolk Construction, Iron Workers Local 7, Sasaki Associates, Thornton Tomasetti, H.J. Russell & Company, BOSS Steel Inc. and MassPort signed the final beam and hoisted it into place along with a fir tree, a traditional symbol of good luck for the building’s future.
Walters Group is incredibly proud to have contributed to such an intricate project in Boston, alongside our valued partners. We look forward to continuing to push boundaries and delivering transformative results in future Boston projects.
Special thanks to our valued partners:
Editorial piece originally published by Sam Barrett on Linkedin
