Recognizing Major Structural Risks in an Earthquake

earthquake valve

In 2010, over 200,000 individuals died in earthquakes around the world. The vast majority of these casualties were caused by collapsed buildings. There are three things that should be prioritized right after an earthquake in order to reduce risk:

  1. Keeping people in and around the building safe.
  2. Preventing gas lines from leaking or exploding.
  3. Minimizing (or at least anticipating) any risk of collapse.

Recognizing structural weaknesses within your building is key to improving earthquake safety for yourself and anyone else who occupies the building. Here are a few high-risk issues that may be present in your building. Carefully considering how to plan ahead can help you to minimize the danger that they may pose.

Poorly Anchored Walls

Earthquakes (of course) shake the ground. In doing so, they may cause various parts of a building to move in different directions, as different elements respond to the movement in different ways, depending on their composition, position, and anchoring. If the walls in the building are not secured or anchored, the walls can pull away from the roof structure, causing the building to become unstable.

The Solution: Hire a retrofitting company to come in and strengthen the walls with an anchor system. This can be done for a relatively low cost.

Poorly Reinforced Concrete Columns

Concrete on its own is a brittle and easily cracked material. The seismic stress caused by an earthquake can easily cause even solid columns of concrete to crumble.

The Solution: A retrofitting company can add reinforced steel or FRP to concrete columns so that they can resist the forces of an earthquake.

Steel Frame Buildings

If your building was built before 1995 and it has been in an earthquakes before, you might have cracks in the steel connections of the building. These are often hard to see because the steel is covered by interior walls, facades, and/or fireproofing.

The Solution: Hire an experienced structural repair engineer to investigate the building. There are also repair and retrofit techniques that are recommended by FEMA for steel frame buildings.  (FEMA 350 to 353).

Extra Precautions for Gas Lines

The gas lines in a building can pose a major risk during an earthquake. Fires after an earthquake are usually caused by blown gas lines, and often, municipalities will shut off main gas valves after an earthquake to prevent damage. However, it’s also the responsibility of any landowner to turn off their gas valve to prevent leaks. This should be a part of your earthquake safety plan, along with coordinated evacuation and meet-up points. An earthquake safety valve is a smart measure to install ahead of time to make it easy to reduce risk of gas leaks and fires on your property. These devices automatically sense an earthquake and shut off gas in response, without the need of any action on your part.

Other Vulnerable Areas of a Building

If you have things like chimneys, stairs, or even marquees, these should all be prepared for an earthquake too. All of these architectural elements should be properly braced to withstand movement.

If you have a building that needs retrofitting or you want more information on what services you can use for earthquake preparedness, contact Saunders Seismic for more information.

Additional resource:

Commercial Property Owner’s Guide to Earthquake Safety