ÜDS-Fen 2003-1 Soru=71

It is pointed out in the passage that the city of San Francisco ----.

When it is completed late next year, a 39-storey
apartment building under construction in San
Francisco will be the tallest precast concrete
structure ever built in an area of high seismic
activity. Its builders are using an innovative new
structural connection that could revolutionize the
way buildings are built in seismic zones.
Conventional cast-in-place and precast systems
survive earthquakes by dissipating the energy
through the structure, often doing irreparable
damage to themselves in the process. The new
connection, developed with help from the University
of Washington, consists of high-strength steel
reinforcing cables and "mild" steel bars that stretch
slightly during an earthquake, then pull the building
back into place. The steel components also
considerably reduce seismic energy before it can
attack the structure. This means less damage to
beams, walls and ceilings.