On September 20, while their classmates were thinking about Saturday's Jackets-Tar Heels match-up, members of Georgia Tech's Earthquake Engineering Research Institute (EERI) chapter were focusing on a football stadium thousands of miles away.
The stadium is UC Berkeley's and the reason for their faraway fascination was their guest lecturer: EERI Director David Friedman.
A senior prinicpal with the renowned Forrell/Elsesser Engineers, Inc., Friedman spoke to the students about his work retrofitting the historic football stadium, which sits directly over the northern segment of the active Hayward Fault.
Situated at the opening of Strawberry Canyon, with the eastern half of the stadium literally carved into the hillside, the non-ductile concrete frame western stadium bowl was seismically retrofitted and modernized with new seating bowl framing, a new press box, and with the preservation and restoration of the historic perimeter concrete wall.
Friedman told the students that the retrofit design created separate “fault rupture zone blocks”, (FRBs) which were reinforced with stiffening concrete shear walls bearing on a mat slab foundation. All of this rested on layers of sand and high-density plastic to reduce friction and thus facilitate the independent sliding, twisting, and tilting that may result from the predicted 6 feet of horizontal fault rupture displacement and 2 feet of vertical fault rupture displacement.
After fiinishing his hourlong talk, Friedman was surrounded by several students, like Pablo Vega Behar who were eager to discuss the specifics of their own research. Ever the student of engineering himself, Friedman listened carefully to their questions and spent quite awhile discussing their concerns.