ClientThe John D. and Catherine T. MacArthur Foundation
BackgroundThe seventeen-story Marquette Building was designed by Holabird & Roche. The building opened in 1895 as the nation's first modern skyscraper to celebrate, rather than hide, its structural skeleton. It features an anchorage system consisting of thirty-seven roof-mounted anchorage posts, forty-five double-loop wall-mounted anchorage plates, and six single-loop wall-mounted anchorage plates that were installed to provide points of attachment for lifelines and equipment tie-down.
SolutionAfter installation, WJE performed general visual observations of the external appearance of the various anchorages. The observations indicated that the anchorages were in the good condition and installed in general accordance to the original design documents.
To test the system, WJE developed the testing protocol, designed and fabricated custom testing jigs, and performed the load tests. The custom testing jigs are designed to be kept on-site by the owner. Each anchor was tested for its intended use. During the testing, the anchorages were monitored visually for inelastic deformations.
All roof-mounted anchorage posts, the majority of the double-loop wall-mounted anchorage plates, and all single-loop anchorage plates successfully sustained the test load without noticeable deflections. At several of the double-loop wall-mounted anchorage plates, testing was halted due to excessive deflections. The anchors were repaired and retested and successfully sustained the test load. WJE issued a certification record to the client and provided recommendations for annual inspection, maintenance, and retesting.