Experimental verification of a stay cable delta frame model

The accuracy of a finite-element model depends on the assumptions made during modelling. A combined experimental and analytical approach which uses a minimum of expensive instrumentation and construction loading to verify the modelling assumptions and validate the mathematical model was used to study a delta frame on the Veterans' Glass City Skyway (VGCS). The VGCS is a twin segmental box girder cable-stayed bridge with three lanes in each direction located in Toledo, Ohio. The delta frame is a complex and critical element of the bridge that transfers loads from the box girders to the stay cables. It was instrumented with a sparse array of strain gauges. A small number of strain gauges were placed in regions of expected high strain. The model was calibrated using the prestressing loads and was used to investigate potential cracking during construction of the delta frame and was incorporated in a larger model of the entire bridge. The accuracy of the work was confirmed by inspection for cracking and strain measurements on the completed bridge.