Cal Stadium Quake Retrofit

[Narrator] Memorial Stadium at UC Berkeley

has one critical fault, the Hayward Fault,

running right down the middle and under the goalpost.

So the university recently embarked

on $321 million seismic retrofit.

Sections of seating over the fault have been converted

into surface rupture blocks.

They're built on stone columns,

and they're sitting on slippery polyethylene sheets

and three feet of sand.

All that reinforcement means the surface rupture block

can handle a vertical displacement

of up to two feet without crumbling.

The press box, cantilevered out

above the stadium's west side, weighs 1,000 tons

and could fall down onto the stands.

So engineers designed vertical walls

of steel cable reinforced concrete,

and they put 16 silicone filled shock absorbers

between the walls and the seats.

Result, the box shakes but stays upright.

(drum roll)