Table of Contents:
- Lesson 1: Welcome and Overview
- Lesson 2: Structural Damage and Mitigation Measures
- Lesson 3: Non-structural Damage and Mitigation Measures
- Lesson 4: Official Information and Resources
Lesson 1:
Welcome and Overview
As a member of FEMA’s Hazard Mitigation disaster workforce, you are expected to be able to explain to the public:
1. Future risks associated with the hazard event that resulted in the disaster declaration
2. Mitigation measures available to improve personal safety and reduce or eliminate the risk of future damages to structures and personal property
This Independent study course is part of a series of five, intended for the Hazard Mitigation disaster workforce. These courses address basic mitigation measures to reduce risk from earthquakes, floods, hurricanes, tornados, and wildfires, at a level appropriate for communication to the general public. For more information about the other courses, refer to the EMI website at http://training.fema.gov.
Course Overview
The goal of this course is to enable you to select the essential hazard mitigation information to communicate to members of the public following an earthquake event.
To help accomplish this goal, by the end of this course you will:
- Recognize how earthquakes cause structural damage and identify mitigation measures that protect buildings from this type of damage
- Identify non-structural mitigation techniques designed to protect personal property and individuals in an earthquake
- Recognize the importance of directing individuals to local building officials, engineers, and other specialists before starting repairs
- Select official FEMA information, publications, and websites that support the mitigation recommendations made to a specific target audience
Screen Features
Click on the Exit button to close this window and access the menu listing all lessons of this course. You can select any of the lessons from this menu by simply clicking on the lesson title.
Click on the Glossary button to look up key definitions and acronyms.
Click on the Help button to review guidance and troubleshooting advice regarding navigating through the course.
Track your progress by looking at the Progress bar at the top right of each screen. To see a numeric display, roll your mouse over the Progress bar area.
Follow the bolded green instructions that appear on each screen in order to proceed to the next screen or complete a Knowledge Review or Activity.
Click on the Back or the Next buttons at the top and bottom of screens to move backward or forward in the lesson. Note: If the Next button is dimmed, you must complete an activity before you can proceed in the lesson.
Navigating Using Your Keyboard
Below are instructions for navigating through the course using your keyboard.
Use the “Tab” key to move forward through each screen’s navigation buttons and hyperlinks, or “Shift” + “Tab” to move backwards. A box surrounds the button that is currently selected.
Press “Enter” to select a navigation button or hyperlink.
Use the arrow keys to select answers for multiple-choice review questions or self-assessment checklists. Then tab to the “Submit” button and press “Enter” to complete a Knowledge Review or Self-Assessment.
Warning: Repeatedly pressing “Tab” beyond the number of selections on the screen may cause the keyboard to lock up. Use “Ctrl” + “Tab” to deselect an element or reset to the beginning of a screen’s navigation links (most often needed for screens with animations or media).
JAWS assistive technology users can press the Ctrl key to quiet the screen reader while the course audio plays.
Receiving Credit
You may take a test on the material covered in this course to demonstrate that you have learned the information.
To receive credit:
1. Complete all of the lessons. Each lesson will take between 10 and 30 minutes to complete. It is important to allow enough time to complete the course in its entirety.
REMEMBER... YOU MUST COMPLETE THE ENTIRE COURSE TO RECEIVE CREDIT. If you have to leave the course, do not exit from the course or close your browser. If you exit from the course, you will need to start that lesson over again.
2. Pass the final exam. The last screen provides instructions on how to complete the final exam.
Lesson Summary
This completes this lesson.
In this lesson, you learned:
- What this course is about
- How to complete this course
- How to receive credit for this independent study course
Lesson 2:
Structural Damage and Mitigation Measures
An earthquake is a sudden, rapid shaking of the Earth caused by the breaking and shifting of rock, usually along a fracture, or fault, in the Earth’s outer shell.
This shaking produces seismic waves, which can travel through the Earth or along its surface. These waves also cause buildings to shake, often with catastrophic results.
There are two types of mitigation measures that can reduce earthquake damage: structural and non-structural. This lesson will focus on structural mitigation measures. Lesson 3 will focus on non-structural measures.
In this lesson you will learn:
- How an earthquake’s sudden rapid tremors can damage buildings
- How strengthening a structure’s continuous load path can help protect a building from earthquake damage or collapse
- How to mitigate against earthquake damages to two weak points in a building--garage doors and masonry chimneys
At the end of this lesson you will:
- Recognize the factors that contribute to structural earthquake damage including structure design, construction methods and materials, adherence to building codes, and soil type
- Recognize the secondary impacts from earthquakes that may cause structural damage
- Identify the connections along the continuous load path that should be reinforced to improve the overall structural integrity of a building
How an earthquake causes structural damage
Structures are damaged during earthquakes when they are too weak or too rigid to resist the earthquake’s strong rocking force.
Earthquakes can crack walls and foundations, make a building uninhabitable, or collapse the building completely.
Secondary impacts of earthquake damage may include fire, chemical spills, broken sewage lines, contaminated drinking-water supply, loss of power, and loss of communication systems.
Structural mitigation measures reduce the risk of building damage or collapse through carefully engineered actions to maintain the integrity of the building’s structural support system. This can be accomplished by reinforcing key elements of a building.
Continuous Load Path
The structural integrity of a building can be improved by reinforcing connection points along the continuous load path of a structure.
The important connections as shown in the diagram are:
- Roof to upper floor walls
- Upper walls to lower walls
- Lower walls to main floor
- Main floor to foundation
Strengthening these connections from the roof to the ground helps ensure that the building will be able to adequately withstand the forces associated with earthquake shaking.
Metal brackets and straps are used to strengthen these connections. To be effective, these brackets and straps should be attached at the studs and rafters, not to the plywood sheathing.
When all of the connections are properly reinforced in this manner, a building is less likely to collapse.
The methods for reinforcing the continuous load path vary for each level of a structure.
The connections between the roof and top level walls are strengthened by:
- Properly nailing the roof sheathing to the roof joists and the roof joists to the top of the walls that support the roof
- Adding blocking—short cross beams— between roof joists, especially where the roof meets the exterior walls
- Bracing all roof framing
- Avoiding the use of heavy roof coverings such as concrete tiles
Strengthening the connection between levels can also be accomplished by using properly nailed structural plywood sheathing in specific wall sections. These sections of wall are referred to as shear walls.
- Shear walls must use structural sheathing, must be properly nailed in specific patterns, and must be anchored at the corners
- Shear wall size is specified by building code
Metal straps may also be used to connect the levels of a structure. These straps must be nailed to the studs and not just the sheathing.
The connection between the lower walls and the main floor is strengthened by:
- Adding wood cross beams called blocking between each floor joist at the end of each joist and at all interior load-bearing points
- Adding connection straps between the joists and the top of the foundation
- Ensuring that connections are made to the studs and not just the wall's sheathing
The entire structure must be secured to the foundation according to local codes. For example, building codes may require that the structure be bolted to its foundation using ½ inch bolts with a 3 inch square plate washer every 4 to 6 feet along the foundation.
Garage Doors and Chimneys
Two of the largest unsecured items in a structure are often overlooked. They are garage doors and masonry chimneys.
Large garage doors may create a gap in the shear capacity of the garage wall so they offer no structural support. This creates a “soft story” which can lead to structural failure.
It is important to reinforce the narrow wall on either side of a garage door, especially if there is a story above the garage. This mitigation is critical to the integrity of the garage in a seismic event, and special engineering is recommended.
A masonry chimney can be braced to keep it secure during an earthquake by encircling it with long metal straps every few feet along its length and connecting it to the structure at other reinforced points such as wall studs.
This completes this lesson. In this lesson you learned:
- How an earthquake’s sudden rapid tremors can cause building to shake, often with catastrophic results
- How strengthening a structure’s continuous load path can help protect a building from earthquake damage or collapse
- How to mitigate against earthquake damages to two weak points in a building--garage doors and masonry chimneys
- Help protect people from injury
- Reduce the risk of damage to furniture, utilities, and interior surfaces
- Prevent items from shifting and blocking exits
- Damage to utilities, interior surfaces, and contents
- Shifting or falling of utilities, appliances, and furniture that may block exits or injure people
- Flood damage, which sometimes accompanies earthquakes, through the purchase of flood insurance
- Recognize non-structural mitigation measures that can protect appliances, and the utilities (gas/electric) that supply those appliances during an earthquake
- Identify why it is important to secure both large furniture and loose items and how to secure these items to prevent damage from an earthquake
- Identify why flood insurance is considered a mitigation measure for some areas
- flooding caused by levee or dam failure
- coastal area inundation by a tsunami
- Appliances in the house that are connected to utilities
- Large furniture items
- Unsecured items in the house such as drawers and cabinet doors
- Loose items such as countertop appliances and computers
- Flood damage, which may accompany earthquakes
- The importance of directing the public to local building officials before they begin repairs or rebuilding
- Which FEMA publications are available to help the public understand earthquake mitigation
- Which FEMA publications are available to help professionals understand earthquake mitigation
- What FEMA-approved online resources are available for earthquake mitigation
- How to provide mitigation advice to the public
- Recognize the importance of why the public should be directed to local building officials before repairing or rebuilding structures damaged in an earthquake
- Recognize FEMA publications that promote earthquake mitigation
- Identify the correct actions to take when advising the public regarding earthquake mitigation
- Building codes, permits, inspection requirements, and zoning ordinances may be involved
- A floodplain ordinance may affect rebuilding when the structure has sustained substantial damage
- Building officials will reinforce the point that only licensed professionals are qualified to perform structural repair or structural mitigation work
- Anchoring Large Equipment Properly
- Anchoring Tall Bookcases and File Cabinets
- Anchoring and Bracing Propane Tanks and Gas Cylinders
- Bolting Sill Plates to Foundations
- Installing Latches on Drawers and Cabinet Doors
- Mounting Framed Pictures and Mirrors Securely
- Restraining Desktop Computers and Appliances
- Using Flexible Connectors on Gas and Water Lines
- Rapid Visual Screening of Buildings for Potential Seismic Hazards (FEMA 154)
- Pre-standard and Commentary for the Seismic Rehabilitation of Buildings (FEMA 356)
- Techniques for the Seismic Rehabilitation of Existing Buildings (FEMA 547)
- Incremental Seismic Rehabilitation Series (FEMA 395-400 and FEMA 420)
- Guidelines for Design of Structures for Vertical Evacuation from Tsunamis (FEMA P-646)
- Vertical Evacuation from Tsunamis: A Guide for Community Officials (FEMA P-646A)
- Refer to publications/websites that reinforce or provide additional information about rebuilding or repairing to reduce future risk of damages
- Do not give specific repair directions. Always direct people to local building officials when they are planning repairs or mitigation
- Remember that you are THE face and voice of hazard mitigation. What you say and do makes a real difference in people’s lives!
- The importance of directing the public to local building officials before they begin repairs or rebuilding
- Which FEMA publications are available to help the public understand earthquake mitigation
- Which FEMA publications are available to help professionals understand earthquake mitigation
- What FEMA-approved online resources are available for earthquake mitigation
Lesson 3:
Non-structural Damage and Mitigation Measures
Earthquakes cause non-structural as well as structural damage. Anything that is not properly anchored or secured within a structure can fall, break, or cause injury during an earthquake. Non-structural mitigation measures:
In this lesson you will learn about mitigating:
At the end of this lesson you will:
Utilities and Appliances
Non-structural mitigation techniques can be implemented to protect utilities and appliances from earthquake damage.
These measures include securing hot water heaters and other large appliances to adjacent wall studs with metal straps.
Propane and other fuel tanks can be chained to either the foundation or across several studs in the wall.
Other large appliances can be secured using heavy duty nylon-wrapped guide wire or chains to help keep them in place and functioning.
Earthquake damage can also be mitigated by the use of flexible connectors between appliances and the gas or electric supply. Flexible connectors can reduce the risk of secondary hazards like gas leaks, fire, and explosion.
Easily accessible shut-off valves at the gas and water meters, as well as at appliances, make it easier to avoid these secondary hazards, especially if any tools needed to assist in shut-off are stored close by.
Large Furniture Items
Large furniture items, such as bookshelves, dressers, cabinets, and china hutches can be secured with iron angles, eye hooks, and similar hardware properly anchored into wall studs.
Anchoring these items reduces the risk that they will fall and damage other objects, injure people, or block escape routes from the structure.
Unsecured Items
Cabinet doors, drawers, and other storage containers can be secured with common child-safety latches. This can keep personal items and household chemicals contained so they don't become hazards during or after an earthquake.
Storing incompatible chemicals in separate low, latched cabinets prevents mixing of those chemicals if their containers break.
Securing Loose Items
Even commonly used items such as televisions, counter-top kitchen appliances, computer monitors, and printers can be secured with special hooks, Velcro, bungee cords, double-sided tape, and similar products.
The risk of injury to people from moving or falling objects can be greatly reduced by using these easy to install, non-structural mitigation measures.
Flood Insurance
Additional sources of potential damage associated with the shifting of the Earth caused by earthquakes include:
If communities and individuals face these potential hazards, the purchase of flood insurance is one way to mitigate financial risk.
Hazard Mitigation Insurance Specialists are available in the Joint Field Office to provide further information about the National Flood Insurance Program.
This completes this lesson.
In this lesson you learned about non-structural earthquake damage and mitigation measures to reduce risk of damage to:
Lesson 4:
Official Information and Resources
Hazard Mitigation staff have a variety of FEMA resources available to help educate the public on earthquake mitigation techniques. Other resources are intended for the enrichment of building and emergency management professionals. Spend the time needed to become familiar with the purpose and audience for the resources and publications that are included in this lesson.
At a disaster, the Hazard Mitigation Community Education and Outreach (CEO) group, in collaboration with the state, will decide which of these approved publications and resources support the Hazard Mitigation Strategy for the disaster.
In this lesson you will learn:
At the end of this lesson you will:
Local Building Officials
When advising members of the public about reducing the risk of future hazard damages, always tell them to visit the local building official before beginning any repairs or rebuilding because:
FEMA Resources for the General Public
Below are FEMA mitigation resources relevant to this hazard. These can be accessed from the FEMA website.
Earthquake Safety Checklist (FEMA 526) is a quick reference guide on preparing for an earthquake and preventing earthquake-related damage to homes.
Earthquake Safety Guide for Homeowners (FEMA 530) provides guidance on strengthening homes against earthquake damage.
Home Builder’s Guide to Earthquake- Resistant Design and Construction (FEMA 232) provides information on current best practices for earthquake resistant house design and construction.
Protect Your Property from an Earthquake is an online “How To” series available on www.fema.gov which covers:
Reducing the Risks of Nonstructural Earthquake Damage: A Practical Guide (FEMA 74) describes sources of nonstructural earthquake damage and provides building owners with information on effective methods of reducing potential risks from such damage.
Seismic Considerations for Communities At Risk (FEMA 83) provides information to individuals and community officials about assessing seismic risk and making informed decisions about seismic safety in communities.
The Quakesmart Toolkit provides guidance and tools to the private sector, its owners, managers, and employees about the importance of earthquake mitigation and the simple things they can do to reduce the potential of earthquake damages, injuries, and financial losses.
Earthquake Basics--Science, Risk, and Mitigationwill be an online, independent training module with a focus on the awareness of the basics of earthquakes and earthquake safety. The course is being designed for homeowners, business owners, and anyone in the general public. Short quizzes may be included to make it interactive and to boost retention.
FEMA Publications for Professionals
Other Resource for Professionals
FEMA also provides guidance publications for tsunamis, which may be triggered by earthquakes.
Other Resources
There are several websites that contain earthquake mitigation information. Aside from official FEMA websites, there are FEMA-partner organizations that provide comprehensive, user-friendly information and guidance on earthquake mitigation.
The HM Disaster Workforce Website houses a wealth of hazard mitigation information. It can be accessed from the internet via the Homeland Security Information Network using any computer or from the intranet using a FEMA computer.
The same information is contained in both locations, but the intranet version is behind the firewall. You will need to have a user id and password to access either website.
Another partner organization is the Institute for Business & Home Safety (IBHS). Its mission is to reduce the social and economic effects of natural disasters and other property losses by conducting research and advocating improved construction, maintenance, and preparation practices. IBHS hosts the DisasterSafety.org website.
The Federal Alliance for Safe Homes, Inc, known as FLASH, is a non-profit organization dedicated to promoting disaster safety and property loss mitigation across a variety of natural hazards, including earthquakes. Their website, FLASH.org has preparedness and post-disaster materials that Hazard Mitigation staff or the public can easily access.
Information on earthquake hazards, including hazard maps and recent earthquakes, can be found at http://earthquake.usgs.gov/.
Advising the Public
When speaking with members of the public about reducing the risk of future hazard damages:
Lesson Summary
This completes the final lesson in this course. In this lesson you learned about:
