Poly Corporation Headquarters – Structural Engineering -
The Poly Corporation Headquarters features a unique engineering component created specifically for the building: The Rocker. Inspired by an understanding of structures as moving entities rather than static objects, The Rocker supports the world's largest cable-net glass wall while releasing the effects of earthquakes and heavy winds. Additionally, it facilitates the suspension of an eight-story museum structure within the building’s atrium.
Structural analysis showed that the support for the 22-story-tall glass atrium wall could not be reasonably achieved using a conventional two-way cable-net. It could, however, be achieved if the 90-meter-high by 60-meter-wide enclosure was broken down into smaller segments. A cable-stayed system was introduced by using two large-diameter, parallel-strand bridge cables in diagonal fold lines while anchoring to the museum structure. The museum structure acts as a counterweight for the cables, introducing pre-stress and providing the required stiffness to resist out-of-plane loads caused by wind on the cable-net. In addition to the diagonal cables, two additional cables and The Rocker were introduced at the rear of the museum structure to assist in its suspension.
Recognizing that the building would sway in multiple directions during an earthquake, the team developed a mechanism that would manage these demands while introducing no additional force into the base building structure. In the plane of the cable-net facade when swaying, one of the two diagonal cables lengthens as the other shortens, with The Rocker acting as a “reverse pulley.” It acts as a pulley by using steel castings/plates designed to pass between one another and interconnect with steel pins, allowing for movements in both directions.