With his 260 meters of height, the Transamerica pyramid It was, from 1972 to 2018, The highest building in San Francisco, making it a recognizable symbol of the Californian city. A visionary project of the architect William L. Pereiradeveloped on deep foundations 16 meterswith an elevation of 48 floors and a total surface of 49 000 m2. The characteristic pyramidal shape of the building at 600 of Montgomery street In the north area of the city is inspired by the sequoies, the large trees typical of the western coast of the United States, and has been the subject of strong debate and criticism at the time of the approval of the project.
The characteristics of the tResame America Pyramid
The Transamerica pyramid It is one of the most iconic buildings in the city of San Francisco. The building, with its characteristic morphology square -based pyramidalculminates with a peculiar spire covered in anodized aluminum. The structure, high 260 meters, reaches in elevation 48 floors. The building dominates the Chinatown and the Financial District of the city and at the base there are the entrances, overlooking a pedestrian portico, characterized by a system of oblique beams with trellis. The four sides of the building, also oblique, are covered with a characteristic quartz powder, which gives the facades the light color visible from the outside. On all four sides there are well 3 678 Quadrangular windows.
One of the most characteristic elements are undoubtedly the two large sails, in the shape of a parallelepiped, which stand out from the 27th floor and host 4 of the 18 lifts present within the structure. On the top of the two large sails there are panoramic terraces.
The building develops a total surface of 49 000 m2with a peculiar distribution of the walkable square meters. It starts from 2 065 m2 of the 6th floor, to get to 235 m2 of the 48th.
Engineering challenges in a highly seismic area
At a purely engineering level, the main challenge concerned the need to design a structure capable of resist to constant seismic stresses which characterize the area of the American western coast, and in particular the city of San Francisco. The foundations consist of an throttle of 16,000 cubic meters of reinforced concrete, on which special bollards have been installed capable of dampening the effects of the horizontal stresses to which a structure is typically subjected in the event of seismic activity.
Another structural element capable of giving greater stability is precisely the system of oblique beams, arranged trellis, that develop on a greater area than the side prospects. This structural complex also gives the building greater resistance in the event of seismic stresses. The effectiveness of the project was demonstrated during the earthquake of 1989 which hit the city of San Francisco, during which, the structure, subjected to 15 seconds to an earthquake of magnitude 6.9, He resisted very well, not reporting any damage.
Crown Jewel, the characteristic spire of the Transamerica Pyramid
The most characteristic element of this skyscraper is the spire, nicknamed Crown Jewel. The element, consisting of a steel skeleton of 64.6 meters, with a coating formed by cracking steel grids, from which night lighting transpires with 1,000 watts projectors each, installed inside the element. These projectors are arranged in such a way that they can change color depending on the need. For air safety, at the height of the spire, a red lighthouse is installed, always from 1,000 watts.
The architect Pereira chose to give the project the characteristic pyramid shape since, according to its evaluation, this characteristic form would have allowed one better lighting not only of the internal environments to the building, but would also have allowed the sunlight to illuminate the surrounding areas The area on which the building would arise. This choice was inspired by sequoietrees that can also reach 80 m in height, of which the area of the American West Coast is full.
The history of the project
The transameric Pyramid project was commissioned to the architect William L. Pereira In the 1967from John Beckett, at the time CEO of the Transamerica corporation. The following year, in 1968when the project was officially presented, it aroused many controversies.
Despite the multiple controversies on the project, the construction site was finished in 1972, with a total cost of 32,000,000 dollars. Originally owned by the Transamerican Corporation, the building then passed to GE Capital following the acquisition of the Transamerican. Through different subsequent transitions of ownership, in 1999 the entire structure was purchased by the Dutch insurance company Aegon, However, he chose to keep the original name. In 2009, following an important renovation work, the Transamerica Pyramid Center obtained the Leed Platinum certification from the Green Building Council for its practices environmental sustainability, which include energy and water saving, the decrease in polluting emissions and the improvement of internal environmental quality. Today, the building represents a distinctive element of the city skyline and an iconic point of reference of the Financial District, also appearing among the highest skyscrapers in the world and being recognized as California Historical Landmark.
