30 seconds summary
- Earthquake preparedness is essential for homeowners in seismic zones. You need to focus on structural retrofitting, like bolting your house to its foundation and bracing cripple walls, informed by the understanding of subsurface risks that specialized firms address in their geological analysis.
- Inside the home, secure all heavy furniture, water heaters, and appliances using straps and anchors to prevent them from falling.
- Finally, develop and practice a family emergency plan, know your safe spots (Drop, Cover, Hold On), have a 72-hour kit ready, and know how to immediately shut off your gas and water mains after the shaking stops
Introduction: Understanding and Mitigating Seismic Risk
For homeowners living in seismically active areas, the threat of an earthquake is inevitable. The effects can range from minor property damage to severe structural failure, posing risks to both property and lives. While no home can fully withstand the force of a large earthquake, preparation is a homeowner’s most powerful defense. Seismic safety involves more than just purchasing an emergency kit. It includes structural retrofitting, securing non-structural elements, planning, and practiced response. By taking these steps, homeowners can reduce their vulnerabilities and protect their homes and families, ensuring a quicker and more resilient recovery post-quake. Companies like eifgeosolutions can help guide homeowners in implementing seismic safety measures, offering expertise in retrofitting and disaster preparedness.
I. Pre-Earthquake Preparation: Securing Your Home and Property
Effective earthquake preparedness begins long before the shaking starts. It revolves around two main areas: strengthening the home’s structure and preventing interior items from causing injuries.
A. Structural Assessment and Retrofitting
The primary goal of structural retrofitting is to ensure the house remains firmly attached to its foundation and can withstand seismic forces. Older homes, especially those built before modern seismic codes, are more vulnerable to damage. Retrofitting can include foundation bolting, cripple wall bracing, and chimney safety measures.
- Foundation Bolting and Anchoring
Many older homes rest on their foundation without being bolted, risking slippage or shifting during strong shaking. Foundation bolting involves drilling through the sill plate and securing it to the foundation with anchor bolts, which prevents the house from shifting off its base. In high-risk areas, professionals may recommend stronger bolting solutions, such as epoxy-set bolts. - Cripple Wall Bracing
Cripple walls are short wooden walls between the foundation and the first floor. If unbraced, they are vulnerable to collapsing, causing significant structural damage. Bracing these walls with plywood or OSB (Oriented Strand Board) sheathing ensures they can resist lateral seismic forces and prevents collapse. - Chimney Safety
Masonry chimneys, while visually appealing, are prone to collapse during an earthquake due to their weight and rigidity. Homeowners should inspect chimneys for cracks or weaknesses. Some may opt for professional reinforcement, such as external steel braces, or replace masonry chimneys with lighter, non-structural metal flues. - Consulting a Professional
Retrofitting requires expertise to assess and address a home’s vulnerabilities. A licensed structural engineer or retrofit contractor should be consulted to ensure compliance with local codes and to avoid exacerbating existing weaknesses.
B. Non-Structural Hazard Mitigation
While structural damage can be catastrophic, most injuries during an earthquake result from non-structural hazards like falling objects. These issues can be addressed with simple and inexpensive preparations.
- Securing Furniture and Appliances
Tall and heavy furniture such as bookshelves, entertainment centers, and dressers should be anchored to the walls with brackets, straps, or specialized furniture anchors. Water heaters, which are heavy and pose a fire hazard if they fall, should be strapped securely to wall studs. Similarly, large appliances like refrigerators and washers should be anchored to prevent them from blocking exits or causing further damage. - Cabinet Latches and Breakables
Items in kitchen and bathroom cabinets can fall and cause injuries. Installing child-proof or earthquake-specific latches helps prevent cabinets from opening during shaking. Fragile items should be stored on lower shelves, and mirrors or artwork should be mounted with closed-loop hooks or earthquake putty to prevent them from falling off walls.
C. Utilities and Systems
Utility lines can be a significant hazard during an earthquake. Knowing how to safely shut off gas, water, and electricity is crucial for preventing fires, flooding, or other dangerous situations.
- Locating and Operating Shut-Offs
All family members should be familiar with the location of the main gas, water, and electrical shut-offs. A tool like an adjustable wrench should be kept near the gas shut-off valve for quick access. Practicing how to operate these valves is crucial, especially if power is out or if there’s panic following a quake. - Automatic Gas Shut-Off Valves
In high-risk areas, installing an automatic seismic gas shut-off valve is recommended. This device cuts off the gas supply automatically when strong shaking is detected, reducing the risk of fires due to ruptured gas lines. - Flexible Utility Connections
Rigid pipes are prone to cracking during ground movement. Using flexible connections for water, gas, and plumbing systems allows them to move with the building during seismic events, reducing the risk of leaks or ruptures.
II. The Homeowner’s Emergency Kit and Plan
No matter how secure a home is, having a well-stocked emergency kit and an emergency plan in place is essential.
A. The “Go-Bag” Essentials
A “Go-Bag” should be packed with enough supplies to last at least 72 hours. It should be easily accessible and stored in a safe location.
- Sustenance and First Aid
The kit should include one gallon of water per person per day and non-perishable food that doesn’t require cooking. It should also contain a comprehensive first-aid kit and a week’s supply of any necessary prescription medications. Other essentials include a battery-powered radio, flashlights, and extra batteries. - Safety and Tools
The kit should include utility shut-off tools, gloves, a multi-tool, duct tape, and a loud whistle for signaling rescuers. A dust mask or respirator will protect against airborne debris. Additionally, sturdy shoes should be kept near each bed to avoid injury from broken glass or debris. - Important Documents and Cash
Essential documents such as insurance policies, identification, and important contact information should be stored in a waterproof, fireproof container. Cash is also necessary, as ATMs may be inoperable after an earthquake.
B. Developing a Family Earthquake Plan
A family emergency plan is critical for ensuring a calm, coordinated response during an earthquake.
- Safe Spots and Practice Drills
Identify safe spots in every room (e.g., under sturdy tables or desks). Practice the “Drop, Cover, and Hold On” technique regularly. Everyone should know where the safest furniture or structural support in the home is. - Communication and Reunification
Communication can be challenging during a disaster, so designate an out-of-area contact person to serve as a communication hub. Establish a primary meeting point near the home and a secondary meeting point farther away, in case the home is unsafe or inaccessible.
III. During an Earthquake: The Immediate Response
When the shaking begins, every second counts. Prioritize safety and adopt protective actions immediately.
A. Inside the Home
The priority is to get to the safest location and adopt the “Drop, Cover, and Hold On” position until the shaking stops.
- The Drop, Cover, and Hold On Protocol
If you are near sturdy furniture, get underneath it and hold on to a leg to keep it in place. If no sturdy cover is available, drop to the floor away from windows and cover your head and neck with your arms. Remain in this position until the shaking stops. - Staying Away from Hazards
Move away from glass, exterior doors, and any unsecured furniture. If you’re in the kitchen, drop immediately and cover your head. If in bed, stay there and use a pillow to shield your head.
B. Outside the Home
If you are outdoors when an earthquake hits, move to an open area away from buildings, streetlights, or utility poles. If driving, pull over to a safe spot away from overpasses or trees and wait for the shaking to stop.
IV. Post-Earthquake Recovery and Safety
After the shaking stops, the risks of aftershocks, fires, and structural instability remain. Proceed cautiously and follow safety procedures.
A. Immediate Actions and Hazards
- Aftershock Danger
Aftershocks can cause further damage, so maintain a “Drop, Cover, and Hold On” position until the threat of aftershocks subsides. - Checking Utilities and Fire Prevention
Check for gas leaks or electrical hazards. If a gas leak is detected, shut off the gas and evacuate the home. Do not turn the gas back on yourself. If you detect electrical issues, avoid using electricity until a professional can inspect the system.
B. Inspecting the Structure
Before entering the home, check the exterior for visible damage such as cracks in the foundation, leaning walls, or damaged chimneys. Inside, inspect for cracks in walls or ceilings and check for pipe ruptures. Document the damage for insurance purposes before beginning repairs.
Conclusion
Seismic safety is an investment in your home and your family’s future. By strengthening your home, securing hazardous items, preparing an emergency kit, and practicing a family emergency plan, you can reduce the risks and enhance your ability to respond effectively during and after an earthquake. The peace of mind that comes from knowing you are prepared is invaluable—start taking action today.