Maintaining Stability on Unstable Ground
The new Massachusetts Bay Transportation Authority (MBTA) Iron Horse Park Operations Control Center is designed to house dispatching and administrative operations for the MBTA north-side commuter rail system and the dispatching operations of the system for a commercial freight rail operator. The new 24/7 mission-critical facility features a clerestory that allows abundant natural light into the primary dispatching area, a state-of-the-art video wall, and doubly redundant MEP systems to protect against single points of failure. The challenges associated with constructing this essential facility on a site that could liquefy in an earthquake were identified early and drove several decisions regarding the ground floor level and foundation system. The MBTA selected Simpson Gumpertz & Heger, Inc. (SGH) to lead a multi-disciplinary design team for the design of the new facility. SGH served as the project’s Structural Engineer of Record (SEOR).
The building is a steel braced frame structure on reinforced-concrete grade beams and pile caps supported by steel H-piles driven into glacial till. A steel deck carries diaphragm loads at the low roof and high roof levels, and a concrete slab on metal deck serves as the elevated second-floor diaphragm. A two-way reinforced concrete structural slab at grade that spans between grade beams carries diaphragm loads at grade.