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What You Can Do Next |
Most residents must understand that the risk of dying in an earthquake is extremely low. However, the risk of damage to your home can be significant, particularly if it is located in a high intensity area.
The most common damage from earthquakes to single-family homes built prior to the 1940s is foundation damage. The "fix" to prevent this damage is to bolt the foundation sill plate to the concrete foundation and to brace or put plywood sheathing on the inside of the "cripple" walls between the foundation and the first floor.
Mobile homes typically fall off the jacks that support them when exposed to intense ground shaking. Again, earthquake bracing systems can be installed to mitigate this problem.
For those who live in apartments or condominiums, the problems are more complex and the solutions more costly. Again, if the buildings were constructed prior to the 1940s, the potential problems are far greater than for newer construction. The spectacular failures to the apartments in the Marina District of San Francisco occurred largely in pre-1940s vintage buildings with parking on the first floor. Parking can even be a problem in buildings built after 1940. For example, many apartments with ground floor parking collapsed or failed in the Northridge earthquake. The tragic deaths at the Northridge Meadows Apartments occurred in a three-story apartment building in which a large portion of the ground floor was parking. When this ground floor parking collapsed, the adjacent ground floor apartments collapsed as well.
Photo is provided as a courtesy of the U.S. Geological Survey
Falling objects within your home will likely result in the greatest losses and pose a significant threat of injury. Just because you cannot push something over easily does not mean that the heavy object will not topple, causing injuries.
Cupboard doors (including sliding doors) can open in earthquakes. Cupboards containing cleaning solutions or other chemicals, or dishes that are valuable, should be fitted with positive latches.
 | Heavy bookcases and tall furniture should be screwed to wall studs. |
| Mirrors, bookcases and other heavy objects should be anchored or removed from near your beds. |
Photo is provided as a courtesy of the U.S. Geological Survey
Your gas hot-water heater should be secured to the wall studs. All gas appliances should be connected to the gas supply with a short piece of flexible tubing. Propane gas storage tanks should be designed not to overturn and roll.
Everyone should have emergency water, food, and prescription medications on hand. First aid and CPR training is also useful.
Recommendations for an "Earthquake Kit" are available from your local Red Cross chapter, local or County Office of Emergency Services, or by looking in the front of your telephone book.
...from the American Red Cross:
Employee Earthquake Preparedness for the Workplace and Home. American Red Cross, 1988. 12 pp. ($1.00 from your local Red Cross Office or by mail from Red Cross Disaster Services, 1550 Sutter Street, San Francisco, CA 94109)
Safety and Survival in an Earthquake. American Red Cross, 1989. 52 pp. ($3.00 from you local Red Cross Office or by mail from American Red Cross, Los Angeles Chapter, 2700 Wilshire Boulevard, Los Angeles, CA 90057, $3.00 plus $1.00 postage and handling)
The Emergency Survival Handbook. American Red Cross, 1989. 63 pp. ($3.00 from you local Red Cross Office or by mail from American Red Cross, Los Angeles Chapter, 2700 Wilshire Boulevard, Los Angeles, CA 90057, $3.00 plus $1.00 postage and handling)
An Ounce of Prevention: Strengthening Your Wood Frame House for Earthquake Safety. California Office of Emergency Services, 1993. 36 pp. (Available from ABAG, as Pub. No. P93001BAR, $3.00 plus $1.00 postage and handling)
An Ounce of Prevention (Video). California Office of Emergency Services, 1993. (Available from ABAG, as Pub. No. P93002BAR, $10.00 plus $5.00 postage and handling)
Organizing Neighborhoods for Earthquake Preparedness. California Office of Emergency Services, 1993. 64 pp. (Available from ABAG, as Pub. No. P93006BAR, $4.00 plus $3.00 postage and handling)
Reducing the Risks of Nonstructural Earthquake Damage -- A Practical Guide. Third Edition. By Wiss, Janney, Elstner Associates for FEMA, 1994. (Available from ABAG, as Pub. No. P94001BAR, $8.00 plus $2.00 postage and handling)
General HOME Preparedness Information Kit. (Set of leaflets covering personal preparedness, emergency supplies, foundation bolting, sheathing of cripple walls, water heater strapping, emergency food supplies.) California Office of Emergency Services, 1988. (OES, Oakland, single sets free -- phone 510-286-0873)
Home Buyer's Guide to Earthquake Hazards. California Office of Emergency Services, 1989. 13 pp. (OES, Oakland, single copies free -- phone 510-286-0873)
The Homeowners Guide to Earthquake Safety. 1992. Calif. Seismic Safety Commission Rpt. SSC 92-02, 28 pp. (Avail. from SSC, 1900 K St., Suite 100, Sacramento, CA 95814, $2.25)
Reducing Losses from Earthquakes through Personal Preparedness. By W.J. Kockelman, 1984. U.S. Geological Survey Open-File Report 84-765, 21 pp. (USGS, $2.75).
Businesses should improve their knowledge by conducting:
| audits of general earthquake vulnerability; and |
| risk assessments to point out ways to avoid risk through avoiding areas of problem soils/geologic conditions, use of "buffer" zones around hazardous areas, and hazardous materials inventory control. |
Schools and businesses can mitigate risk by:
| use of specially-designed shelving systems or containers; |
| use of special structural designs for buildings, tanks and pipeline supports; |
| use of seismic restraints on suspended ceilings, light fixtures, equipment or computer floors (such as bracing, anchors, and straps); and |
| control of hazardous materials risk through secondary containment or chemical isolation and separation of incompatible chemicals. |
Mitigation measures can be improved. Requirements in OSHA standards and the Uniform Building Code are minimums. Just because you cannot push something over easily does not mean that the heavy object will not topple, causing injuries.
| Cupboard doors (including sliding doors) can open during earthquakes. They should be fitted with positive latches. |
| 1" to 1-1/2" shelf lips may not be adequate to restrain chemical reagent bottles in violent ground shaking. Lip designers should look at the size and shape of what is on the shelf. |
| Some shelf anchors can fail. They should be designed to restrain full, rather than empty, shelves. |
| Tanks and pipelines can have problems due to inadequate attention to details. For example, anchoring thin-walled tanks may make leakage more likely by contributing to the puncturing of the vessel. Proper detailing is essential. |
| Gas cylinders cause problems. For example, C-clamp restraints for gas cylinders can slip off lab benches. They can slip out from under single chains. Cylinders in use should be anchored with two chains (one high, one low). |
Emergency capabilities should be improved and maintained:
| use back-up systems for power, communications and water; |
|
| improve evacuation routes through (1) avoiding placing shelving in major exit corridors, (2) reducing the risk of window breakage, and (3) structural retrofit of exit areas; |
| improve the usefulness of emergency personnel through (1) training of special response and inspection teams, (2) anchoring furniture and equipment in their offices; and (3) using databases to track those personnel and their training; and |
| develop emergency response and warning systems. |
Employee training programs are essential. If not trained, employees can be very "innovative" in defeating mitigation -- and in designing inadequate solutions. As many employees as possible should be trained in first aid, CPR and fire safety. Drills should be held to exercise the emergency response plan on a regular basis.
...from the American Red Cross:
Employee Earthquake Preparedness for the Workplace and Home. American Red Cross, 1988. 12 pp. ($1.00 from you local Red Cross Office or by mail from Red Cross Disaster Services, 1550 Sutter Street, San Francisco, CA 94109)
Business Resumption Planning Guidelines. California Office of Emergency Services, 1993. 28 pp. (Available from ABAG, as Pub. No. P93008BAR, $5.00 plus $2.00 postage and handling)
Earthquake Preparedness Guidelines for Hospitals. California Office of Emergency Services, 1987. 151 pp. (Available from ABAG, as Pub. No. P88001BAR, $10.00 plus $3.00 postage and handling)
Earthquake Preparedness Training for Businesses. California Office of Emergency Services, 1990. 88 pp. (Available from ABAG, as Pub. No. P90001BAR, $25.00 plus $5.00 postage and handling)
Hazardous Materials Problems in Earthquakes: A Guide to Their Cause and Mitigation. By J.B. Perkins, E. Wyatt, J.H. Schmidt, and G. Selvaduray, 1990. ABAG, 72 pp. (Available from ABAG as Pub. No. P90002EQK, $12.00 plus $3.00 postage and handling)
Toxic Gas Releases in Earthquakes: Existing Programs, Sources and Mitigation Strategies. By J.B. Perkins, E. Wyatt, and G. Selvaduray, 1991. ABAG for the South Coast Air Quality Management District, 374 pp. (Available from ABAG as Pub. No. P91002EQK, $20.00 plus $5.00 postage and handling)
Reducing the Risks of Nonstructural Earthquake Damage -- A Practical Guide. Third Edition. By Wiss, Janney, Elstner Associates for FEMA, 1994. (Available from ABAG, as Pub. No. P94001BAR, $8.00 plus $2.00 postage and handling)
Earthquake Preparedness Activities for Child-Care Providers. California Office of Emergency Services, 1989. 54 pp. (Available from ABAG, as Pub. No. P89002BAR, $8.00 plus $2.00 postage and handling)
Earthquake Preparedness: What Every Childcare Provider Should Know (Video). California Office of Emergency Services, 1993. (Available from ABAG, as Pub. No. P93003BAR, $10.00 plus $5.00 postage and handling)
Earthquake Ready: Preparedness Planning for Schools. California Office of Emergency Services, 1990. 76 pp. (Available from ABAG, Pub. No. P90002BAR, $7.00 plus $3.00 postage and handling)
Reducing the Risks of Nonstructural Earthquake Damage -- A Practical Guide. Third Edition. By Wiss, Janney, Elstner Associates for FEMA, 1994. (Available from ABAG, as Pub. No. P94001BAR, $8.00 plus $2.00 postage and handling)
The Commercial Property Owners Guide to Earthquake Safety. 1993. Calif. Seismic Safety Commission Rpt. SSC 93-01, 32 pp. (Avail. from SSC, 1900 K St., Suite 100, Sacramento, CA 95814, $3.25)
Large variations in the level of ground shaking hazard exist in the San Francisco Bay Area. Thus, local government programs dealing with earthquake hazards should recognize these differences.
Mitigation options include:
land use/zoning controls,
particularly for critical or hazardous
facilities;
requirements for soils
and geotechnical studies;
special building design
requirements;
special requirements
for nonstructural components;
hazardous building
retrofitting and abatement programs;
programs to strengthen
housing;
special requirements
related to hazardous materials;
infrastructure and
lifeline requirements;
disclosure requirements
and posting of signs;
disaster response planning;
reconstruction and
redevelopment planning; and
public information
and education programs.
Policy statements on all of these strategies can become a part of the safety element of a jurisdiction's general plan. However, these general plan policies must be backed by programs, ordinances and regulations to have any meaningful impact on our safety.
A land use control might be to avoid particular problem areas in the siting of new critical facilities, such as fire stations. Zoning controls might include restrictions on facilities handling hazardous materials "on shakier ground."
Geotechnical studies and environmental reviews in areas of strongest shaking should be required to be performed by licensed professionals and go beyond statements of fact to include the conclusions and recommendations for appropriate mitigation.
Building codes should be recognized as only minimum standards. Construction supervision by a structural engineer can prove effective for critical facilities in high intensity areas. In addition, local governments should improve the qualifications and encourage specialized training and continued education for building department personnel responsible for structural review.
Although unreinforced masonry buildings have become a symbol for hazardous buildings, they are not the only potential problem. For example, many older cities are dominated by wood-frame houses over 50 years old which were built before such buildings were required to be bolted to their foundations. Cities should consider requiring bolting and strengthening when such buildings are sold or within a fixed period. Because of the large number of such buildings and limited local resources, cities may find it appropriate to target neighborhoods "on shakier ground."
...from the Association of Bay Area Governments:
Earthquake Recovery: A Survival Manual for Local Government. California Office of Emergency Services, 1993. 488 pp. (Avail. from ABAG, as Pub. No. P93007BAR, $14.00 plus $6.00 postage and handling)
Earthquake Vulnerability Analysis for Local Governments. California Office of Emergency Services, 1989. 16 pp. (Avail. from ABAG, as Pub. No. P89003BAR, $4.00 plus $2.00 postage and handling)
Liability of Local Governments for Earthquake Hazards and Losses -- A Guide to the Law and Its Impacts in the States of California, Alaska, Utah and Washington. By J.B. Perkins and K. Moy, 1989. ABAG, 52 pp. (Available from ABAG as Pub. No. P88003PLN, $12.00 plus $3.00 postage and handling)
Putting Seismic Safety Policies to Work. By M. Blair-Tyler and P.A. Gregory, 1988. California Office of Emergency Services, 44 pp. (Available from ABAG, as Pub. No. P88006BAR, $9.00 plus $2.00 postage and handling)
Seismic Retrofit Incentive Programs-A Handbook for Local Government. By D. Barzel and W. Darragh, ABAG, for the California Office of Emergency Services, 1992. 252 pp. (Avail. from ABAG, as Pub. No. P92001BAR, $20.00 plus $5.00 postage and handling)
Reducing the Risks of Nonstructural Earthquake Damage -- A Practical Guide. Third Edition. By Wiss, Janney, Elstner Associates for FEMA, 1994. (Available from ABAG, as Pub. No. P94001BAR, $8.00 plus $2.00 postage and handling)
California at Risk--Steps to Earthquake Safety for Local Governments. By G.G. Mader and M. Blair-Tyler, 1988. Calif. Seismic Safety Commission Rpt. SSC 88-01, 92 pp. (Avail. from SSC, 1900 K St., Suite 100, Sacramento, CA 95814, $10)
Geologic Principles for Prudent Land Use -- A Decisionmaker's Guide for the San Francisco Bay Region. By R.D. Brown and W.J. Kockelman, 1983. U.S. Geological Survey Professional Paper 946, 97 pp. (Available from USGS, $5.50)
Look Before You Build--Requiring Geologic Studies for Reviewing Building Projects. By M. Blair Tyler, Spangle Associates, 1995. U.S. Geological Survey Circular 1130, 59 pp. (Available from USGS, free of charge)
Seismic Safety and Land Use Planning -- Selected Examples from California. By M.L. Blair and W.E. Spangle, 1979. U.S. Geol. Survey Prof. Paper 941-B, 82 pp. (Available from USGS, $6.50)