Transamerica Prymarid

One of the first structures built to withstand an earthquake and its associated tremors was the Transamerica Pyramid, also called the Transamerica Tower. In this seismically active region, no engineering was spared to keep the building safe from earthquake tremors.

Located on 600 Montgomery Street, it rises 853 feet and 48 floors and was the eighth tallest building in the world in 1972. At the highest floor, 48, there is a conference room that has unobstructed 360 degree views of the San Francisco Bay area.

The building is designed in a modern fashion, constructed in steel, reinforced concrete, pre-cast quartz aggregate and glass. It triangular in shape, working its way up to the top of the 212 foot spire. There are two concrete structures on the east and west sides that protrude from the 29th floor rising upwards, called wings. The wings are part of the structural engineering that went in to keep the building sturdy during an earthquake, but they also have function. The eastern wing serves as is an elevator and the western wing includes a staircase.

To reinforce the building even more, there is a truss system on the ground and lower floors which is designed to support both vertical and horizontal stress. Under the truss beams are X beams over the ground floor, designed to brace the building against any type of torque movement. This torque and stress reinforcement was tested in 1989 during the 71. magnitude Loma Prieta earthquake. The building successfully withstood the quake with no damage and no injuries.

In addition to above ground stress reinforcement, there is a brace in the foundation designed to resist tremors,. It consists  of a 9 foot deep concrete mat foundation, which lies on top of a steel and concrete block that goes 52 feet underground. This foundation contains 16,000 cubic yards of reinforced concrete, including over 300 miles of steel reinforcing rods. This concrete assists with additional support of Compressive stress and tensile stress.

The Pyramid is a self contained structure, which has its own 1.1-megawatt power system.

Construction began in the fall of 1969 with the first tenant moving into the office building  in 1972.

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