Everyone Should Know About Seismic Retrofit

If you live in a zone with a high level of seismic activity, you’ve probably felt at least a minor quake before. The experience can be scary, and can catch you completely off guard. While you may know the risks, you may not have a safety plan or even a good idea of how to react in the event of an earthquake. No home alarm system in the world can protect against natural disasters, only warn you that something is already wrong. As many of the major earthquake danger zones have at least one or more major cities within their bounds, many residents simply trust that their residence, apartment building, office building, and other frequented locales have been made earthquake safe. However, many buildings and clearly cities were primarily constructed before the term “seismic retrofit” even existed. To get more information about the level of safety of your high rise or multi-level apartment building or office, start by learning some of the basic terms surrounding seismic retrofit. It will improve not only the safety of you and your loved ones, but your home security. Start with these levels of performance objectives as defined by Performance Based Earthquake Engineering.

Seismic failures occur when a house either is displaced from its concrete foundation, or when walls below main floor areas of the house collapse.

In the first case, improvement consists of strengthening the connections between the house and the foundation. Improvements to prevent the second type of failure consist of both supplementing any existing connections to the foundation and strengthening the sub-area supporting walls.

Public Safety Only. If your apartment or office building is designed for public safety only, it means the structure is unlikely to collapse so a safe exit will likely be possible. A strong earthquake, however, can still cause enough damage to the structure that it will require demolition after. The good aspects of this level of performance include a safe escape for you and your family, the downside includes the possible complete destruction of your belongings and home or office. Concerns like debris and other hidden dangers may also impede escape from a ‘public safety only’ building.

Structure Survivability. If a structure meets this level of performance objective, the structure will remain safe for exit during an earthquake situation, allowing occupants plenty of time to escape and make a safe exit. The structure will likely require a great deal of repair after before it can be reoccupied, so expect long delays before being able to return home. Again, this type of seismic retrofit will improve your home security in the sense your home will not be destroyed and your family will likely be fine, but will not guarantee your safe exit without a scratch.

Structure Functionality. Hospitals, for example, must achieve this level of retrofit that maintains a building’s primary structure, leaving the structure undamaged and undiminished in utility. While some repairs will likely be required, they are small details that will not affect the overall usability of the building such as minor cracks. If your apartment or office is located in such a structure some injuries will likely still occur to building residents, but overall survival rates for your family and property will be high.

Structure Unaffected. Many historic structures or buildings of high cultural significance have undergone this expensive retrofit that guarantees a structure will hardly show an earthquake has happened. While everyone would like to live or work in such a building, the fact of the matter is that any seismic retrofit from the level of structure functionality up is considered extremely safe, and an excellent measure to take for personal and home security.

The existing strength of your home, as well as its earthquake vulnerabilities, can be determined through a visual inspection by a trained and experienced earthquake specialist. Typically, this person will make recommendations for strengthening which, if implemented, will reduce the risk of both damage to the property and personal injury to its occupants.

To get started today or for more information, contact us today to schedule a FREE on-site inspection by our team of soft-story experts or call us now at (818)287-8002.

Posted on Thursday, May 2nd, 2019.