Built to Resist the Big One

This is a bridge for the record books. Now nearly complete, the San FranciscoOakland Bay Bridge Skyway is a world class concrete structure for several reasons:

• Its precast girder segments are some of the largest bridge segments ever built in the world. The huge segments weigh 300 to 800 tons, whereas more typical segments weigh 40 to 60 tons.
• The structure’s pre-tied reinforcement cages are among the largest ever set in North America. The pier column reinforcement cages, placed in one section, weigh up to 300 tons.
• The bridge has its foundations in deep Bay mud, yet it is close to two major California fault lines and must resist a major earthquake.