Identify Potential Weaknesses and Begin to Fix Them
Common building problems
Buildings are designed to withstand the downward pull of gravity, yet earthquakes shake a building in all directions. How well will your building withstand strong ground shaking? Go to earthquakecountry.org for detailed information on how to fix these and other problems.
This house in Petrolia slid off its foundation in the 1992 Cape Mendocino earthquake
Unbraced cripple walls
Cripple walls in this house failed in the 1992 Cape Mendocino earthquake
Soft first stories
The garage level of this apartment complex was weaker than the rest of the building and collapsed in the 1994 Northridge earthquake.
This Eureka chimney twisted and almost collapsed in an earthquake in 1954.
Does your community:
- Notify you if a tsunami warning is issued?
- Have designated evacuation zones and posted tsunami hazard signs?
- Practice evacuation drills?
Pier and Post Foundations
"Pier and post" or "post and beam" foundations consist of wooden posts on isolated concrete footings, which support the entire structure. Many homes in rural Northern California use this foundation system. This type is particularly vulnerable to the strong side-to-side shaking from earthquakes. There is no question that the best foundation to resist earthquake shaking is a continuous perimeter foundation, but for many Northern California residents, the cost of installing such a foundation is prohibitive. It is possible, however, to strengthen your pier and post foundation at relatively low cost. The bracing system pictured here will increase resistance to lateral forces for your home. The bracing should be installed around the perimeter of the structure and, at a minimum, every second line of interior posts. This type of strengthening should be considered adequate for short term stabilization until you are able to install a permanent, concrete, perimeter system.
Find out more at earthquakecountry.org.