Larger Angles of Inclination than the Leaning Tower of Pisa: The Veer Towers in Las Vegas CityCenter
The Veer Towers are at the very heart of CityCenter in Las Vegas. What is special about the 37 story luxury condominium towers is their angle of inclination. Each of the towers leans 5 degrees from center in opposite directions. As a reference, the angle of inclination of the world famous Leaning Tower of Pisa is only 3.97 degrees.
Due to the complex statics, the construction of the tower entailed special requirements for all of the companies involved in the project. On level 3, six massive girders had to be cast in place and posttensioned successively in accordance with construction progress.
A total of 33 type 27x0.6" DYWIDAG Post-Tensioning Tendons were installed in tight quarters in the approx. 2.7x2.7m (9ftx9ft) girders. Each of the six girders had a different size, length, quantity of tendons, and stressing force.
In the first phase, the 27x0.6" Tendons were installed in the six girders. After the concrete had cured, individual tendons were partially post-tensioned.
In phase two, when construction work had reached level 15, the DSI team returned to level 3 in order to slightly increase the post-tensioning force of the DYWIDAG Strand Post-Tensioning Tendons.
The 33 tendons were only post-tensioned to their final post-tensioning force and grouted subsequently once level 25 had been reached. All in all, DSI supplied 33 type 27x0.6" DYWIDAG Post-Tensioning tendons with approximately 16,000m (53,000lf) of type 0.6" strand and approx. 640m (2,100lf) of galvanized 110mm Ø duct for the condominium towers.
More than a year after the DYWIDAG Strand Post-Tensioning Systems had been installed, the Veer Towers were completed, providing a new slant to the Las Vegas skyline.