Seismic retrofit Facts for Kids

Municipal Services Building in Glendale, California retrofitted with base isolation.

Seismic retrofitting is the modification of buildings that already exist to make them resistant to earthquakes. Seismic retrofitting techniques can be applied to other kinds of natural disasters such as tornadoes and strong winds from thunderstorms.

Seismic retrofit performance objectives

Main levels of retrofitted building structure performance objectives may vary, namely:

Infill shear trusses — University of California dormitory, Berkeley
External bracing of an existing reinforced concrete parking garage (Berkeley)
Port Authority Bus Terminal in New York City
One of many "earthquake bolts" found throughout period houses in the city of Charleston subsequent to the Charleston earthquake of 1886. They could be tightened and loosened to support the house without having to otherwise demolish the house due to instability. The bolts were directly loosely connected to the supporting frame of the house.
Partial failure due to inadequate shear structure at garage level. Damage in San Francisco due to the Loma Prieta event.
Corner joint steel reinforcement and high tensile strength rods with grouted anti-burst jacket below
House slid off of foundation
Low cripple wall collapse and detachment of structure from concrete stairway
Jacketed and grouted column on left, unmodified on right
Additional diagonals were inserted under both decks of this bridge
Obsolete riveted lattice members
Bolted plate lattice replacement, forming box members
Cypress Freeway viaduct collapse. Note failure of inadequate anti-burst wrapping and lack of connection between upper and lower vertical elements.