Transamerica Building
In
the late 1960s, when Structural Engineer Walt Hensolt and his team at Chin & Hensolt
helped design San Francisco's Transamerica Building, Structural Engineers were
just beginning to use mainframe computers and early-stage software to assess
the effects of earthquake forces on building structures. Before then, most
skyscrapers were built like tall rectangular boxes and Structural Engineers
used slide rules and other mechanical aids to design them. Even a handheld
calculator was still a thing of the future.
The Transamerica Building may have been one of those perfect marriages of art and science: a concept that pushed the envelope of design brought into being by technology that pushed the envelope of structural engineering. The solution was the selection of an unconventional design, one that would require thinking beyond the box. The Transamerica headquarters, with its tall pyramid-like tower, is one of the most recognized and celebrated skyscrapers today.
It all began in 1968 when then company President John R. Beckett wanted to allow natural light and fresh air to filter down to the streets around his new headquarters. The result: a refreshing openness that allowed access to the environment.
To
ensure that this tallest building in the San Francisco skyline would perform
well and survive future earthquakes, Hensolt used a 3-D dynamic computer model.
It was one of the first times that this technology was used on a skyscraper.
After consulting with academics and steel industry experts, he developed specialized
welding sequences for the structure's complicated connections. This was done
to ensure their integrity and to preclude fracture due to the intense heat
of welding. This became one of the basis upon which modern welding codes were
written.
When
it was under construction, the Transamerica Building was also making history.
At that time, it was the largest single concrete pour for a foundation ever
in San Francisco. The thickness of the concrete mat foundation totaled nine
feet. The base includes approximately 16,000 cubic yards of concrete, encasing
more than 300 miles of steel reinforcing rods.
The
building includes 48 floors with the largest floor on the fifth level. The
smallest floor, not surprising, is the 48th, measuring only 45 feet per side
and containing 2,025 square feet of space. The building's height reaches 853
feet, including the 212-foot spire. Today, there are more than 1,5000 people
employed by more than 50 firms working in the Pyramid.
