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Description:
Located in Chicago, it was designed by Frank O. Gehry. Anyone familiar with Gehry's work will know that the geometry is always extreme, with free-flowing curves and surfaces in multiple planes. Gehry uses Catia Software to provide a 3-D wire frame model, which is then passed to the engineer, and to the steel detailer. The model in the initial stage had no sizes or orientation of members. Sizing the members was not a problem, but determining the correct orientation became increasingly so.
To determine the proper member orientation, a three-point plan was established at every one of the thousands of members, and they were rotated into proper position. Member placement diagrams were created for all C, E and W elements, to enable us to check these orientations before connecting could begin.
The complexity of the geometry ensured that every connection was different. The configuration of the joints were unpredictable and as they were modelled, Dowco worked closely with the engineer to resolve the conflicts that arose.
Using 3-D modelling Dowco could visualize the complications in the connections, the challenge was to present drawings in such a way that the members could be fabricated. After consultations between Dowco and Lejeune, a method using laser points was arrived at. The problem went back to Dowco's R&D team, who developed a new macro for the purpose. This method assisted the fabricator in assembling the steel components and checking the configuration before shipping to the site.
Dowco used it's expertise by adding target points to certain points on the steel and at the bracket plates. We then created coordinate reports for these points from the Tekla Structures model. These were then compared to the as-built' coordinates on the job site. It was obvious to all the participants that these reports were imperative for the quality control on the project.
To further enhance procedures, Dowco provided an Excel spreadsheet to calculate the distance between every two targets in any element. This program became an excellent tool for the erector to check the relative distance between parts of the element and to adjust the overall geometry of the elements.
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