Forell | Elsesser Engineers provided structural engineering services for this 29-acre development which includes three new office buildings and two new parking garages. The new office buildings are six-story structures ranging from 225,000 s.f. to 300,000 s.f. totaling 762,000 s.f. The office towers are ornamented by two ground-level pavilions and a seating structure of wood and steel construction. Glulam beams with cross-laminated timber (CLT) roof panels are used to create a sail-like canopy that rests atop steel columns.
The steel-framed office structures include a buckling restrained braced frame (BRBF) lateral system. The office towers are supported on deep foundations with pile/pilecap system interconnected with grade beams. F|E is responsible for the full design of the foundation system including the concrete piles. The exterior wall undulates through the buildings resulting in significant cantilevers, ranging up to 15’-0”. All the office buildings will have an extensive roof garden on the third-floor terraces creating a “park-like” setting with trees and walkways.
Customized Solution
- The pavilion and seating structure utilizes mass timber as a structural and aesthetic design solution. The Pavilion roof is designed with Cross-Laminated Timber (CLT) supported on glulam girders. The roof has 5-ply CLT panels to support a double cantilever of ten feet and houses a café.
- BIM was utilized not only for coordination within the design team, but also as a tool for material quantity takeoff to facilitate overall steel, rebar, and concrete weight takeoff at each major design milestone for cost comparison.
- Finite Element Analysis (FEA) was used for cantilever design and vibration analysis to economize the overall framing design around the perimeter of each floor
- F|E facilitated close coordination between the architect and the BRB manufacturer to provide custom pin connections at the interior BRBFs that remain exposed in finished condition.