The last major part of the new eastern span of the Bay Bridge, a piece that is estimated to last 150 years, was installed over nine hours Saturday.

Arm cranes laid truck after truck of strong concrete Saturday starting at 7 a.m. on what will be the eastbound touchdown of the Bay Bridge's new eastern span.

"About 136 trucks are transporting 1,220 cubic yards of concrete and the space that they're filling in today is roughly 80 feet wide by 1,070 feet in length, that's about three football fields," said Andrew Gordon, Bay Bridge project spokesman.

What gives the bridge its strength is the steel rebar which can handle just about anysized earthquake that either the San
Andreas or Hayward faults can hand out.

"This bridge is designed to withstand the strongest possible ground motion involved with a seismic event within a 1,500 year period," Gordon said.

Because the new section is so long, it will have great flexibility to deal with everything from varying traffic loads to changing temperatures to great earthquakes.

"The concrete will set within two to four hours, that means it's strong enough to stand, but then it needs to cure for about a week," Gordon said. "And after it cures for about a week, then it will be strong enough for vehicles to travel over it."

Work still remains on the new bridge to prepare it for its Labor Day weekend opening, including installing expansion joints in the road-decks and paving.

On Sept. 3, the bridge will be open for at least 150 years of business. Also opening in what will be the year of infrastructure are the Devil's Slide and Caldecott tunnels.

More information about the Bay Bridge opening was available at http://www.baybridgecelebration.com.