Seismic retrofit Seismic retrofit Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries (US, Japan etc.) and late 1970s for many other parts of the world (Turkey, China etc.), many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the
Seismic risk condition. Acquiring and analyzing the specific data for an individual building or facility is one of the most expensive and daunting aspects of seismic risk estimation. Progress is made if one can calculate the 'fragility' or seismic capacity of the components within a structure. In 1999, ASTM produced guidelines for reporting seismic loss estimates on commercial properties, commonly known as Probable Maximum Loss or PML reviews. These guidelines specify the scope of work, qualifications of the reviewer, and proper nomenclature for reporting loss estimates. Seismic risk can be reduced by active programs that improve emergency response, and improve basic infrastructure.