Standing on seismic Mexico City's dry central lake bed or "bowl of jello," where many buildings collapsed in 1985's magnitude 7.3 earthquake, Latin America's tallest building might be mistaken for a giant sitting duck waiting for the next Big One. But on closer inspection, it becomes apparent that the $250-million-plus Torre Mayor, which officially opened last week, is no quack. The 225-meter-tall office tower sparkles with damper-studded, diamond-shaped superdiagonal bracing, architecturally expressed on its perimeter moment frame. It is a giant billboard for seismic strength. The diamonds and dampers offer structural efficiencies and other advantages inside and outall the way to slashed insurance premiums.
The damped steel diamonds that adorn each broad face of the tower have already proven they are more than window dressing. Torre Mayor's lower floors had just been occupied when, on Jan. 21, a magnitude 7.6 quake rocked the city. Almost all of Torre Mayor's occupants were oblivious to the temblor. The tower survived without a scratch (ENR 2/3 p. 16).