Description

The US Bank Tower was formerly the Library Tower and First Interstate Bank World Center. The 73-story seismically engineered building (the tallest west of Chicago) is based on a matrix of overlapping and concentric geometries—one circular, the other orthogonal—that define a series of setbacks up to the full 1,018-foot height. The tower was shaped to create a memorable skyline image. It is the third tallest building ever constructed in a major earthquake zone and was designed to withstand an earthquake of 8.3 on the Richter Scale. The central core structure has a frame that is reinforced in two directions. From the 53rd floor up, horizontal forces caused by wind or earthquakes are dampened by two struts, which are each one floor high. One of its major draws is an Observation Deck, featuring a transparent glass slide between the 69th and 70th floors.