An alarming number of older, low-rise concrete buildings have not been structurally retrofitted for earthquake safety. These two-story to five-story structures may have met the building-code standards of their day, but that time has long passed.
Now, these buildings often fall far short of current building code requirements for structural safety.
Current building codes reflect years of earthquake engineering research and incorporate structural elements designed to allow concrete buildings to bend and stretch without breaking in earthquakes. Older designs lack these features. As a result, older buildings have too little lateral flexibility and can be brittle, thus making them vulnerable to damage and collapse in earthquakes.
Owners of these non-ductile concrete buildings may be required to perform structural retrofits by city ordinances. In 2015, the city of Los Angeles mandated that existing buildings with this type of concrete construction that had a construction permit application dating before January 1977 had to complete seismic retrofitting for structural safety or demolish the building within 25 years. It was estimated that about 1,500 buildings were covered by that ordinance alone.
As an owner of this type of building, earthquakes pose particular risks of legal liability for deaths, injuries and property damage, as well as the costs, effort and time to make proper repairs.
Optimum Seismic’s non-ductile concrete retrofit engineering and construction services can bring these types of buildings up to code for structural safety and protect owners from future legal and financial vulnerability. Constructing structural retrofits on concrete buildings can also reduce insurance and liability costs, as well as improve the value and marketability of the property.