Seismic retrofitting is the process of making your building safer from earthquakes. It involves installing resilient systems in your home that can better withstand tremors. This can be done through the installation of a seismic isolation system, often referred to as Seismic Softening, or Retrofitting. There are two main types of retrofitting, passive and active. Passive retrofit means that your house does not have to be made stronger in order to resist earthquakes; it just has to get better at resisting weaker shocks. Active retrofit means that you have to strengthen your building with concrete walls or steel reinforcement bars Seismic retrofitting. Of course, both require some work and planning before proceeding so read on for more information...
What does seismic retrofitting involve?
A seismic retrofit is when an existing building is equipped with additional systems to improve its resistance to earthquakes. These include reinforcing the building envelope, installing a ground anchor, and increasing the level of the building’s foundation. This type of retrofitting is commonly called “seismic softening”. There are three main types of retrofitting for both passive and active systems. They are: - Seismic Isolation - Ground Anchors - Reinforced Building Envelope (RBE) For seismic isolation, the term “softening” is a bit of a misnomer. You are not actually making the structure “soft” so much as making it less “hard”. You do this through the installation of a “cushion” above the structure. This cushion can be a layer of dense foam, a layer of dense rock, or a layer of dense soil. The seal that is formed between the two is then referred to as the “isolating layer”. In an earthquake, the shaking will cause the structure to move at least a little and the isolating layer will then “cushion” the movement by absorbing some of the force of the movement.
Passive Retrofitting
To retrofit a residential building so that it is more resistant to earthquakes, engineers install a high-density mound of materials above the structure. This mound, often called a Soft-Stop or Soft-Stop Roof, creates the isolating layer. There are many different types of Soft-Stop products, but they all have in common a base material that is denser than the surrounding soil or rock. When an earthquake shakes the building, some of the shaking energy will be transferred to the Soft-Stop layer, but it will have less of an effect on the building below. The amount of shaking energy that is reduced by the Soft-Stop layer is called “softening”. A building that has been retrofitted with a Soft-Stop roof is less likely to collapse in an earthquake. It could, however, suffer serious damage. The Soft-Stop roof could be ripped off or damaged, causing the walls of the building to collapse. The Soft-Stop roof could also be ripped open, allowing rainwater to penetrate the building and cause serious structural damage.
When should you have a seismic retrofit?
If you live in an area where there is a high risk of an earthquake, you should consider retrofitting your home. The risk is highest in areas where the major (M) or high magnitude (H) earthquakes are frequent. This is usually the western coast of the United States, Japan, and the eastern coast of the South Pacific. If you live in an area that has a high risk of frequent earthquakes, it’s a good idea to consider seismic retrofitting your home.
Conclusion
Seismic retrofitting is a critical step toward preparing your home for the future. It can protect you and your loved ones from injury and death during a major seismic event. The materials used to retrofit your home are expensive, but the investment is worth it. It’s easy to do and the benefits are substantial. While a retrofit will not prevent an earthquake, it can reduce the severity of shaking and damage in the event of a seismic event. In order to reduce damage from a seismic event, you must be prepared. Make sure your home is safe by having a structural engineer check the foundation, framing, and other components.
