Thornton Tomasetti, Chicago
Construction of the 1000+ meter tall Jeddah Tower in the Kingdom of Saudi Arabia is currently well under way with all tower piling and raft foundation works completed, and the superstructure concrete reaching 270 meters in height. The presentation focuses on the significant technical engineering challenges of designing the first manmade structure to exceed 1 kilometer in height.
A brief overview of the architectural and master planning essentials for the tower and the surrounding developments is presented as an introduction to this unique, ground-breaking project. Important aspects of the geotechnical site exploration program, piled raft foundation design and significant foundation-tower interaction studies are presented; along with long-term settlement predictions, the completed pile load testing program, and ground seismicity studies. The superstructure frame is composed almost entirely of reinforced concrete walls and coupling beams. The structural system was developed based on the need for simplicity and repetition during the construction process. The concrete bearing wall system chosen is unique for ultra-tall tower schemes in that it relies on no outriggers or belt walls, no column transfers, very little differential shortening in vertical elements, and only 85 MPa concrete strength.
The presentation focuses on the development of the tower structural system including historical precedents, the wind tunnel testing program and other unique aspects of the tower structural engineering design and construction planning. Particularly critical technical issues such as the prediction of vertical shortening due to the long-term creep and shrinkage of the concrete frame, and behavioral characteristics of the tower under lateral and gravity loadings are also highlighted.