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From the Desk of the Executive Director Earthquake Information Providers Group (EqIP) Updates A Rationale for a Government Role in
Mitigating Seismic Update: Homeowners’ Insurance Availability Act of 1997 Public Policy Options and Earthquake
Insurance FEMA’s Project Impact: Building Codes: Encouraging Mitigation
From the Desk of the Executive Director This has been a very busy spring for WSSPC. This year we face the challenge of hosting three conferences in a three month period. We are meeting the goals and at the same time producing publications for each of these conferences, publishing two issues of EQ, issuing the first set of WSSPC Policy Recommendations White Papers, coordinating the WSSPC Awards in Excellence Program, redesigning the WSSPC web site (www.wsspc.org), expanding our Affiliate Members and Partners programs, and enhancing our information exchange for our members.A quick word about the upcoming conferences. By the time you read this, we will have successfully hosted the Western United States Earthquake Insurance Summit. The event focused on the many public policy options that address the provision of earthquake insurance. We hope that following the Summit specific recommendations can be developed for adoption throughout our region and the nation. A published volume will be available for purchase summarizing the many presentors’ ideas and recommendations. We are hosting the WSSPC Annual Conference and the Tsunami Hazard Mitigation Symposium 1998. These concurrent events will be held in Pasadena, California from September 14th to the 18th. In this issue of EQ we have highlighted the schedules for these events. More details, including invited speakers, can be found on the WSSPC web site. I should note that soon WSSPC will be offering EQ free only to its members and by subscription to all others. We hope you enjoy this issue. Earthquake Information Providers Group The Earthquake Information Providers Group (EqIP) continues to meet and coordinate activitites. It recently received grant funding from the National Science Foundation and the Federal Emergency Management Agency to continue its work and to redesign and update its web stie.For more information about the EqIP members and about earthquake hazards in general visit the web site at http://www.eqnet.org. Earthquake Engineering Research Institute Project on Incentives and Impediments to Seismic Strengthening Under contract to the California Office of Emergency Services, Earthquake Engineering Research Institute (EERI) is preparing a white paper on incentives and impediments to taking action to reduce seismic risk. A project steering committee has identified the major considerations and key players in the decision to strengthen a building. By clearly identifying such major considerations and the interaction among them, the project hopes to gain a better understanding of how incentives and impediments influence the process. A set of recommended incentives are under development as part of this project. The white paper should be available by late summer. Contact Sarah Nathe at the California Office of Emergency Services for further information (510-256-0858).
Shah Family Innovation Prize Nominations are now being accepted for the 1999 Shah Family Innovation Prize. This $10,000 prize will honor a young (less than 35 years on January 1, 1999) professional for creativity, innovation and an entrepreneurial spirit in earthquake risk mitigation and management. Call EERI (510-451-0905) to request the brochure describing this award, the selection criteria and the nomination process. 499 14th Street, Suite 320
South Carolina Earthquake Center The newest activities at the South Carolina Earthquake Center at Charleston Southern University are:
P.O. Box 118087
The Natural Hazards Research and Applications Information Center The Natural Hazards Center library database is now
searchable on-line at: Campus Box 482
Multidisciplinary Center for Earthquake Engineering Research The National Center for Earthquake Engineerings Research (NCEER) headquartered at the University of Buffalo, has been re-named the Multidisciplinary Center for Earthquake Engineering Research (MCEER). The MCEER Information Service endeavors to provide a rapid and effective mechanism for the provision of earthquake engineering and natural hazards mitigation information. Activities and services include:
Current focus is on the application of new technologies for enhancement of information transfer, evaluation and assessment of current activities, and collaborative efforts. Projects underway include:
State University of New York at Buffalo
Institute for Business and Home Safety The Institute for Business and Home Safety (IBHS) is an initiative of the insurance industry dedicated to reducing deaths, injuries, property damage, economic losses and human suffering caused by natural disasters. IBHS is working in five areas: Public Education, Land Use Planning, Retrofit, New Construction, and Information Management. Current programs include: Showcase Communities, Web site, Hurricane and Earthquakes, Retrofit guides, Paid Loss Database, and Land Use Planning Tools.73 Tremont Street, Suite 510
Association of Bay Area Governments The Earthquake Program of the Association of Bay Area Governments (ABAG) concentrated on transportation problems during earthquakes in the past year. ABAG published a major report in October 1997 - Riding Out Future Quakes (Perkins and others, 1997). In 1989, the Loma Prieta earthquake closed 142 roads in the San Francisco Bay Area. Five years later, the 1994 Northridge earthquake closed approximately the same number, 140. These earthquakes were only driver’s training for our future transportation emergencies. In the worst case scenario, a rupture along the entire length of the Hayward fault, nearly 1500 streets and highways would be closed. See a summary of the report’s key findings at http://www.abag.ca.gov/bayarea/eqmaps - click on the car! P.O. Box 2050
International Association of Emergency Managers The National Coordinating Council of Emergency Management (NCCEM) is now the International Association of Emergency Managers (IAEM). IAEM’s role as a network of professionals who learn from one another has no boundaries. The new name better reflects the growing international interest in the mission of the organization. Founded in 1952 to give the local emergency management professional a national voice, IAEM still represents and provides a forum for the local manager, and the membership has grown continuously and now includes local managers who are from Canada, Mexico and other countries. The name has changed, but not the mission and purpose. IAEM will continue to support local emergency managers through the regional structure and the international organization. Over 1,700 belong to the organization whose membership includes emergency managers and disaster response professionals from all levels of government as well as the military, the private sector and volunteer organizations. 111 Park Place
A Rationale for a Government Role in Mitigating Seismic Hazards: Incorporating Externalities by Steven Ganz, Western States Seismic Policy Council Often associated with the process of creating or utilizing goods in the marketplace are harmful or beneficial side effects. These side effects are termed by economists as externalities. The cost or benefits of these externalities are born by people other than the producer or consumer of a good. If an externality causes beneficial results it is called an external benefit. A common example of an external benefit is immunization. When I have my son immunized, not only is he protected from disease, but my act also reduces the risk of others catching the disease. Others in society benefit from my transaction, but do not pay any of the transaction costs, therefore they are receiving an external benefit. As a result, it is in society’s interest to encourage such activity through means of subsidizing the transaction.If an externality causes harmful results it is called an external cost. A common example of an external cost is pollution. When a factory emits pollutants into the atmosphere it imposes costs on others not directly involved with any transaction. The price of the good produced is sold without incorporating the costs of the pollution and therefore the pollution is considered an external cost.
So what does this have to do with earthquakes? Mitigating one’s home or business results in external benefits for society. Similarly, not including mitigation measures in one’s home or business during its initial construction, or later rehabilitation, results in external costs. When an individual or business is considering undertaking mitigating measures, only the marginal private benefits are considered. For example, retrofitting a brick chimney to prevent collapse during an earthquake may cost a certain amount of retrofit dollars ($RD). If the homeowner assigns a probability of that chimney falling during an earthquake (P) and the cost of damage due to the chimney’s collapse ($DD), then the homeowner, if risk neutral, will only mitigate if $RD is less than P times $DD. Using proxy numbers, if it costs $500 to retrofit, but the homeowner thought the chance of the chimney falling was 5% and the cost of repairing any chimney damage was estimated to be less than $10,000, the homeowner would not mitigate. Clearly the biggest problem with decisions like these for property owners is assigning correct probabilities for damage. The higher the perceived probabilities are, the more likely the owner will mitigate. However, inaccurate probabilities will result in too much or too little mitigation. The individual property owner does not, and should not, bear the full responsibility of these costs. It is in society’s interest to increase the overall amount of mitigation in order to receive the external benefits from such actions. The problem with the individual property owner using the described calculation is that it ignores the externalities. If the property owner retrofits the chimney and prevents it from falling on an abutting structure, additional costs will be saved — costs that were not incorporated into the homeowner’s calculations. It is in the neighbor’s interest to encourage the property owner to retrofit the chimney and theoretically he should be willing to pay the neighbor to do so. Following this logic the neighbor’s neighbor would act similarly, as would his neighbor, and so on and so on. Because the negotiations and costs for these transactions would be difficult to coordinate individually or would result in expensive courtroom costs, a community-wide effort could be initiated to subsidize the cost of chimney retrofit. There are many external benefits that can be achieved from mitigation. For example, if a large neighborhood fire breaks out after an earthquake due to a poorly secured water heater, the homeowner and his neighbors will suffer the direct losses in their homes. In addition to this damage, the costs of the fire department’s response, the damage to any public infrastructure, communication or utility lines, as well as other damage could occur. All of this damage could be avoided with proper mitigation. Other social or external benefits resulting from individuals undertaking mitigation measures include a reduction in emergency response expenses (fire, police), fire-following expenses (damage to other buildings, emergency response), disaster relief and recovery expenses, and economic loss from business disruption.
Reduce the Gap. The fundamental problem with these externalities is that there is a gap between the amount of mitigation undertaken by individuals and the amount of mitigation that would optimally benefit society. As demonstrated, this is the result of individuals not taking the public benefits into consideration. Graphically, we can see this gap by looking at the benefit/cost curves for the cumulative good of mitigation. It is important to note that these curves represent the aggregate of all the different categories of mitigation, such as retrofit, non-structural mitigation, and land-use planning. Decisions about what public actions should be taken must be made on a category by category basis. The intersection point of the Marginal Private Benefit Curve (MPB, also known as the demand curve) and of the Marginal Private Cost Curve (MPC, also known as the supply curve) signifies the optimal amount of mitigation individuals would consume. This would be quantity Q0 at a price P0. However, for each quantity of mitigation consumed by individuals there is benefit to society as a whole. Therefore we must consider the Marginal Social Benefit Curve (MSB) when determining what is the optimal amount of mitigation. The point at which the MSB intersects the MPC identifies the optimal amount of mitigation consumption from a societal point-of-view. This is represented as the quantity Q*. The gap in mitigation is the difference between Q* and Q0. In order for that quantity of mitigation to be consumed, the price of mitigation needs to be reduced to P*. So what does this mean? We must focus on reducing the gap in the graph to ensure that an optimal amount of mitigation is implemented. This can be done through a series of measures that reduce the cost of mitigation (through subsidies and price controls) or that increase the demand for mitigation (through education and regulation). It is an appropriate role for government and other agencies to reduce this gap and encourage the consumption of Q* mitigation, because the marketplace will not resolve the problem by itself. A tremendous amount of work is being done to address earthquake hazard mitigation throughout the nation. To determine how we should direct future efforts, I suggest two general concepts: 1) Identify and document what efforts are currently underway. 2) Develop strategies that disaggregate mitigation into different categories and seek to find solutions that either reduce the cost to provide mitigation or increase the demand for mitigation. In the next issue of EQ, I will explore these concepts further.
Update: Homeowners' Insurance Availability Act of 1997 For those of you following federal legislation, House Resolution 219 (Lazio-NY) was a bill designed to provide reinsurance to the private hazard insurance markets. However a recent substitute bill has been put in its place. The bill is now designed to provide reinsurance to state insurance programs and state reinsurance programs. The covered hazards included in this bill are earthquakes, perils ensuing from earthquakes, including fire and tsunami, and hurricanes. The following is a summary of the bill as
has been
• Mandates a specified report by the Secretary to the Congress.
Public Policy Options and Earthquake Insurance By Steven Ganz, Western States Seismic Policy Council Policymakers face a daunting task in addressing the issue of earthquake insurance provision. Before addressing this issue, one must consider the conflicting aspects of insurance. It is important to understand that earthquake insurance by itself does not mitigate losses from seismic hazards. While it can help reduce losses from earthquakes, insurance is just one of many policy options. Other options include such things as structural and non-structural mitigation, building codes, and land-use planning. Insurance, when coupled in this manner, can be used as a financial incentive for action. Unless proper incentives are put into place, a fully insured individual has a disincentive to mitigate since the insurer will cover any loss.
Challenges in the Insurance Market What are the challenges faced by private insurers who provide earthquake insurance?
High Correlation of Claims from a Single Event - Because earthquakes are geographically focused events, when one occurs many claims are concentrated in a single area. Because of losses from a single event can be tremendous, insurers are hesitant to offer many policies in an area facing the same hazard.
Low Probability/High Consequence Events - Major earthquakes seldom occur, but when they do, catastrophic consequences follow. Because the limited number of past events and the difficulty in accurately predicting future events, insurers need to utilize the risk assessments from experts. However, these estimates are highly uncertain and ambiguous. For example, scientists predict that a catastrophic earthquake will be centered in the Pacific Northwest, but they do not know if it will occur next year, or if it will occur in 1,000 years, or which specific communities will be affected.
Difficulty in Identifying What Losses May Occur - Although scientists are able to identify the probabilities of an earthquake occurring for a given location, and they can estimate the magnitude and duration of groundshaking, accurately predicting the damage to any given structure remains difficult. For example, homes abutting each other during an earthquake can sustain substantially different damage. Specific site conditions and construction standards can cause wide variations. The vast number of variables involved makes it almost impossible and quite expensive to predict losses.
Lack of Incentive to Take Preventative Action - Because hazard insurance reduces the cost of rebuilding after an earthquake, it makes the homeowner feel more secure and less interested in adopting mitigation measures. This helps to explain the lack of voluntary loss prevention measures among the insured. For instance, an owner of a wood-frame home may lose the incentive to bolt the wooden structures to their foundations and apply adequate bracing after an earthquake insurance policy is purchased.
Adverse selection - When the insured possess information unknown to the insurer, high-risk consumers will purchase low-premium policies designed for lower-risk consumers. In the case of earthquake insurance, this information includes structural aspects of a building such as unbolted foundations or unfastened water heaters. To address this issue, insurers set a rate schedule to capture the varying risk among policyholders. However, adverse selection still occurs even when insurers issue different insurance policies targeted at groups with different risk, because they often fail to differentiate the premium schedule wide enough due to regulatory controls or other reasons. Therefore, insurers will still incur losses because the premium differential fails to discourage high-risk consumers from purchasing the low-premium policy designed for low-risk consumers.
Policy Solutions At the moment, there appears to be no quick fixes on the earthquake insurance horizon. California has begun the process of addressing the problem with the legislative creation of the California Earthquake Authority, which still leaves many problems unsolved. Nevertheless, policy designers will want to carefully consider a number of options.
Adopt and Enforce Building Codes - Local and state governments should adopt and enforce cost-effective building codes that include seismic safety standards for the rehabilitation of old buildings and for the construction of new structures. Well-built structures are one of the most effective ways of mitigating losses from seismic hazards. The reduced losses should result in lower insurance premiums
Use Insurance as Mitigation Incentives - The insurance industry should encourage property owners to build and modify structures to mitigate earthquake damage. Significant safety improvements will result when companies offer insurance premium discounts for mitigation measures, such as bolting foundations and securing water heaters.
Require Hazard Insurance - One controversial proposal would require earthquake insurance as a condition for federally secured mortgages. Currently this is done for flood insurance. As a result, the risk to the homeowner and to the lender would be minimized. However, homeowners should not bear the full burden of these costs since the mortgage lenders will receive the benefit of the insurance. This provision could be enforced by imposing fines or other penalties on the lending institutions, rather than the individual property owner.
Develop A Large Regional Pool for Earthquake Insurance - States should consider the potential benefits of spreading the risk across the Western United States. Right now only a state like California has the financial resources to develop of substantial pool of funds for insurance, but even the Golden State does not have enough communities to fully diversify the risk. Pooling risks can also work if other risks with the same characteristics as earthquakes are included. Combining risks of earthquake with hurricane, volcano and tsunami into a single natural hazard insurance program may solve multiple problems.
Expand the Use of Disaster Bonds for Reinsurance - Insurance companies often resell their insurance policies to a secondary market as a means to lessen their risks. Insurance companies select the risks and package them for sale on the financial market by issuing so called "disaster bonds." These bonds differ from traditional bonds in that bondholders would get paid a high return if no disaster hits in a given year, but they would subsequently lose money in years when disaster struck. For instance, investors of a Florida hurricane bond would not receive coupons or capital based on whether their borrowers default. Rather, they would get paid a high return if no hurricane hits Florida in a given year, and they would subsequently lose money, or even their principal, if a hurricane does. The magnitude of investor’s losses increases with the severity of the disaster. In this way, insurers no longer have to bear the risks and hence do not need large capital reserves. Instead, they could rely on their expertise of selecting risks and marketing them.
Subsidize low-income families - If an earthquake causes damage to a poorly constructed home, often the damage is not limited to that individual structure. For example, fire following earthquakes can destroy entire city blocks. Since low-income families do not have the resources to mitigate or to rebuild, assisting them to retrofit these structures is important.
Next Steps While a comprehensive solution to all of the problems of earthquake insurance may not be readily available, manageable remedies can be implemented. If individual legislators and policymakers take the appropriate steps we can reduce the risks from earthquakes.
FEMA's Project Impact: Building a Disaster Resistant Community The Federal Emergency Management Agency’s Project Impact initiative is about to expand beyond the initial seven pilot communities designated in 1997. By the end of the 1998 fiscal year, FEMA’s Project Impact initiative will be helping at least one community per state to develop local partnerships that will work together to protect families, businesses and communities by reducing the effects of natural disasters. Project Impact is a national effort that aims to reduce the costs of disasters. The initiative challenges communities across the nation to build local partnerships, to assess vulnerabilities to natural hazards and to implement actions that protect families, businesses and communities by preparing for and reducing the damaging effects of natural disasters. The focus of Project Impact is on what happens BEFORE a disaster rather than on simply picking up the pieces afterward. The first round of communities will form a peer-to-peer network of American communities building partnerships and taking actions to better prepare for natural disasters. In each community, a local partnership of government leaders, representatives of the business sector and individuals will provide funding, in-kind services, technical support and labor to undertake disaster-resistant activities. In addition, FEMA will provide technical support and funds to states to provide administrative support to the initiative. "The increasing number and severity of natural disasters demand that Americans take actions to protect their families, homes and businesses," said President Clinton. "Through Project Impact, Americans can build stronger communities before disaster strikes." "Natural disasters cost this country too much in dollars, infrastructure loss, and in a sense of emotional and community well-being," said FEMA Director James Lee Witt. "We must put an end to the damage, repair, damage and repair cycle. Project Impact represents a new vision for the way America deals with disasters." Project Impact is based on three tenets: 1) Mitigation is a local issue best addressed by a local partnership that involves government, businesses, and individuals; 2) Private sector participation is essential for the development of a comprehensive solution that reduces the threat to the economic viability of the community; and 3) Mitigation is a long-term effort that requires long-term investment from all parties. The national launch of Project Impact: Building a Disaster Resistant Community follows the successful demonstration of the program in seven pilot communities that have created a disaster resistant model for communities, businesses and individuals to implement nationwide. The seven pilot sites — Allegany County, Md.; Deerfield Beach, Fla.; Oakland, Calif.; Pascagoula, Miss.; Seattle, Wash.; Tucker and Randolph Counties, W.V.; and Wilmington/New Hanover County, N.C. — were selected for their geographic and demographic diversity and include large cities, rural areas, coastal communities and riverines. All communities – not just those designated by FEMA — can become disaster resistant by using Project Impact materials, including a guidebook and technical assistance from state and FEMA regional offices. The Project Impact Guidebook, as well as a Project Impact brochure and video, are available from FEMA’s publications warehouse at 1-800-480-2520. You can also contact your FEMA regional office, or access the FEMA website at www.fema.gov for more information. Communities invited to become Project Impact communities: ^back to topProviding Safer Buildings Through Modern Building Codes by John R. Henry, P.E. Staff Engineer International Conference of Building Officials It is human nature to resist change, and life would certainly be easier if engineering practices and building codes remained unchanged. Although most of us would undoubtedly welcome less change where seismic design and building codes are concerned, this is an unrealistic wish. Advances in earthquake engineering and the code changes that follow are as dynamic as the world we live in. In order to use the latest technology and ensure highest level of safety in the built environment, it is imperative that building code officials as well as the design and construction communities utilize the most current codes available. The Great Earthquake of 1906 On the morning of April 18, 1906, one of the most significant earthquakes of all time ripped through the City of San Francisco. At 5:12 AM, a foreshock was felt throughout the San Francisco Bay area, and about 20 seconds later, the great earthquake produced violent shocks that lasted 45 seconds and were felt all the way from southern Oregon to Los Angeles. Estimated to be between 7.7 and 8.3 on the Richter1 scale, some research indicates that the San Francisco earthquake caused over 3,000 fatalities, left over 225,000 people homeless, and destroyed an estimated 28,000 buildings.
Kobe Japan Earthquake Kills 6,000 On January 17, 1995, an earthquake measuring magnitude 6.9 struck the region of Kobe and Osaka, Japan, killing 6,308 people and destroying or severely damaging nearly 180,000 buildings. The pre-dawn quake left 300,000 people homeless. The vast majority of fatalities occurred in traditional Japanese housing units of post-and-beam construction with little or no lateral force resisting system.
Iran Earthquake Kills 1,500 On May 10, 1997, an earthquake measuring magnitude 7.1 struck Northern Iran, killing 1,567 people and destroying over 10,500 homes. The quake left 2,300 people injured, and over 50,000 homeless.
Afghanistan Earthquake Kills 2,500 On Saturday, May 30, 1998, an earthquake measuring 6.9 on the Richter scale 1 struck near Rostaq Afghanistan, killing an estimated 2,500 people, including 140 school children. Afghan volunteers immediately on the scene confirmed the death of at least 1,500 people, and estimated the total fatalities may reach 2,500. A similar quake of magnitude 6.1 struck the region on February 4, killing over 2,300 people and destroying over 8,000 homes. These statistics tell a sad story of the kind of devastation and fatalities that resulted from earthquakes that pre-date building codes, or even present day earthquakes that strike areas where outdated building codes exist or the level of code enforcement is inadequate. In stark contrast, the 1989 Loma Prieta earthquake of magnitude 7.1 struck the Santa Cruz Mountains in California. Sixty miles away, in downtown San Francisco, the 49 story Transamerica building shook for over a minute. During the quake, the top story swayed over 12 inches from side to side. Yet the building was undamaged and no one was seriously injured. All tolled, the Loma Prieta earthquake resulted in 62 fatalities. On January 17, 1994, a magnitude 6.7 earthquake struck the densely populated San Fernando Valley area in Los Angeles County, near Northridge, California. The percentage of buildings that were totally destroyed was very small, and most of the severe damage was confined to an area within 16 km of the epicenter. Although the epicenter was located in close proximity to a densely populated area, the quake resulted in 57 deaths. Since the quake occurred in the early morning and on a holiday, the number of fatalities was reduced considerably. While these fatalities are no less tragic, they serve to illustrate the significant reduction in fatalities and demonstrates that one of the most important tools of minimizing loss of life and structural collapse is modern building codes. Building codes serve as the first line of defense against future earthquakes that threaten loss of life and severe property damage, and undoubtedly many lives and untold billions of dollars have been saved by virtue of the earthquake design provisions of the building code. Through the code development process, the hard lessons learned from each significant earthquake have been transformed into the many revisions and improvements in the building code.
Modern Building Codes: An Evolutionary Process Over the course of the last century, major earthquakes have severely damaged or destroyed many buildings and other structures. By carefully examining how buildings respond to earthquake forces, scientists, engineers and code officials have applied the knowledge gained from these unfortunate events to improve building codes so that buildings have a better chance of surviving major earthquakes without collapse or loss of life. In essence, the modern building code represents the result of an evolutionary process where earthquake knowledge translates into progress. It is a process where government, building code officials, the academic community and the engineering profession forge a cooperative relationship that has produced higher levels of understanding of earthquake design. Since the very first edition of the Uniform Building Code (U.B.C.) in 1927, the code has included seismic force design requirements. The 1933 Long Beach earthquake (M 6.3), which devastated several schools in the vicinity, caused the State of California to enact legislation known as the Field Act, which gave the state the responsibility for review and approval of school buildings. In addition, the 1933 Riley Act required for the first time that earthquake loading be considered in the design of all buildings in California. The 1935 Edition of the U.B.C. reflected this trend by requiring that a lateral force be applied to the building equal to 2% of the dead load plus one-half of the live load, adjusted by a factor that depended on the seismic activity zone and the particular type of structural element involved. In 1940, the El Centro earthquake (M 7.1) occurred on the Imperial Fault, killing nine people. Since the quake occurred in a well instrumented area, it produced the first real building response and building period data. Although it only lasted 10 seconds, a surprising ground acceleration of 0.33g was observed. The 1961 Edition of the U.B.C. seismic design provisions, based primarily on the recommendations made by the Structural Engineers Association of California (SEAOC), was revised to incorporate both the building period as well as the type of lateral force resisting system into the design lateral force equation. The 1966 Parkfield earthquake, with a magnitude of only 5.5, produced a 0.5g ground acceleration, which was the highest recorded to date. This demonstrated that earthquake magnitude and ground acceleration were not easily correlated. During the period from 1933 to 1970 California and Nevada experienced over 70 earthquakes in excess of magnitude 5.0; but it was the 1971 San Fernando (Sylmar) earthquake that shocked the community by knocking out hospitals and collapsing several newly constructed concrete buildings in the area. The prevailing viewpoint at the time was that the effective acceleration experienced by buildings in earthquakes was in the order of 0.5g (1.0g is ordinary force imposed by gravity). The San Fernando earthquake produced a remarkable ground acceleration of 1.24g at the site of Pacoima Dam. The state responded by increasing the design requirements for hospitals, and the code officials responded by making further improvements in the seismic design methodology. The 1976 Edition of the U.B.C. included an importance factor which accounted for relative importance of the building, and soil factor which was intended to consider potential site period resonance based on soil properties at the building site. The learning process continued with the next series of significant earthquakes to strike, beginning with the Loma Prieta (M 7.1) earthquake which struck the San Francisco Bay Area in October of 1989, and finally the Northridge quake which struck the San Fernando Valley in January of 1994. These earthquakes pointed out some important issues: (1) a significant increase in acceleration, velocity and displacement occurs near the fault source, (2) deflection (differential movement) of a building results in damage to members and components that are not part of the lateral force resisting system, (3) specific requirements for more redundancy would improve building performance, and (4) the influence of the site soil properties should be refined. In an effort to address these and other issues, SEAOC developed a lengthy code change in 1993 which was eventually incorporated into the seismic design provisions of the 1997 U.B.C..
Looking to the Future: The 2000 International Building Code The building codes used in the United States are currently based on one of three model codes: The Uniform Building CodeTM or U.B.C. (International Conference of Building Officials), the National Building CodeTM or N.B.C. (Building Officials and Code Administrators International), and the Standard Building CodeTM or S.B.C. (Southern Building Code Congress International). As indicated, the seismic design provisions of the current U.B.C. are based on the recommendations of the Structural Engineers Association of California (SEAOC), in a document known as the SEAOC Blue Book2. On the other hand, the seismic design provisions of the other two model codes are based on the National Earthquake Hazards Reduction Program (NEHRP) Recommended Provisions of the Building Seismic Safety Council (BSSC)3. Currently the 1996 edition of the NBC and the 1997 edition of the SBC contain seismic design provisions which are based on the 1991 NEHRP Provisions. The current state of affairs, where three different model codes are used in different parts of the country, is about to change. In order to provide a single unified code that can be used anywhere in the United States, the three model code groups have joined forces and formed the International Code Council (ICC). The ICC will produce the first edition of a new unified model code, called the International Building Code (IBC), by the year 2000. The seismic design provisions of the 2000 IBC will be based on the 1997 NEHRP Provisions, with some modifications made during the code development process.
Measuring the Shake, Rattle and Roll Although scientists began recording earthquakes as early as 1880, the actual magnitude of vibration was not accurately recorded even into the 1930’s. A major obstacle in gathering accurate seismic activity data is (1) significant earthquakes occur at irregular and often long intervals, and (2) the recording instruments must be in the vicinity when the event happens. Obviously, recording earthquakes represents a long term commitment, since the instruments must be in place and ready to capture the next earthquake while it happens. In the 1940’s seismic recording instruments began being installed in buildings with the hope of gathering more reliable data on building response to seismic activity. It was not until the 1971 San Fernando earthquake (M 6.5) that accurate building response data was obtained. Although primitive by today’s standards, the seismic data collected from the 1971 San Fernando earthquake and the 1979 Imperial Valley earthquake (M 6.6) were invaluable in developing a better understanding of the effects of earthquakes on buildings. Beginning with the 1967 Edition, the Uniform Building Code required that earthquake recording instruments be installed in specific buildings located in areas of high seismic activity. In 1972, the Strong Motion Instrumentation Program (SMIP) of the California Division of Mines and Geology (CDMG) was instituted to broaden the information data base needed to refine the design of structures subjected to earthquakes in that state. Since 1972, SMIP has been placing sensitive instruments at strategic and seismically active locations throughout the state. Today, largely through the efforts of CDMG, instruments are installed in a variety of building, bridges, dams, aqueducts and many other structures throughout the United States, giving scientists and engineers a wealth of data which can be used to improve building design and construction practices with the goal of preventing loss of life and reducing property damage.
The Building Code: A Recipe for Safer Buildings The fundamental concept of a building code is to provide a level of protection to the public who occupy buildings. Similar to a recipe, a building code is a set of rules that when followed, produce a result that we can be reasonably confidant meets our goals. In the case of a building code, the goal is to produce safe buildings that afford a minimum level of protection to the occupants by preventing collapse and allowing safe exiting from the building. A cake recipe consists of a step-by-step procedure for constructing a cake. It specifies the ingredients, prescribes the order in which the ingredients are to be put together, and stipulates the specific proportions of ingredients to be used. Recipes serve two purposes: first, to raise our confidence level in the expected outcome, and secondly, someone else can follow the same recipe with the confidence of obtaining similar results. A building code is nothing more than a recipe for constructing buildings. Like a recipe, it consists of a step-by-step procedure. It specifies the materials (ingredients) to be used, prescribes how the materials should be put together, and stipulates the specific proportions to be used. We use building codes for the same two reasons: to raise our confidence level in the expected outcome (a safe building), and secondly, so that someone else can follow the same code with the expectation of obtaining similar results.
Pay Now or Pay Later One of the most important lessons to be learned from many past earthquakes is that it costs much less to prepare for earthquakes than it does to repair the damage afterwards. In regards to loss of life, there is no value that can be assigned. We must marshall all of our resources and combine the collective knowledge of scientists, engineers, code officials, government and the construction industry to prevent catastrophic collapse and loss of life from earthquakes. Section 1626.1 of the 1997 U.B.C. states that the purpose of the earthquake provisions is primarily to safeguard against major structural failures and loss of life, not to limit damage or maintain function. On the face of it, this may seem disconcerting until we focus on the hard realities. There is no question that we have the engineering expertise and technology to design and build earthquake-resistant structures, but they would not be affordable. The harsh reality is that we must continually balance economic considerations with minimum levels of safety. We must set our goals so that our buildings are both affordable and safe. We cannot expect buildings resist the design earthquake without sustaining damage, anymore than we can expect our buildings to be subjected to the design fire, flood or wind storm without sustaining damage. What is imperative is that our codes safeguard against catastrophic collapse and loss of life for both new and existing construction.
Building Safe Structures Requires Teamwork One of the many lessons learned from the Northridge earthquake is that it takes a vast team of individuals to produce safe buildings that conform to the code. The team includes the architect and engineer who design the building, the plan reviewer who checks the plans for code compliance, the trades worker who constructs the building framework, the building inspector who reviews the field construction for conformance with the approved plans, and the specialty inspector who observes critical aspects of the construction process. We must all see ourselves as playing on the same team, and charged with a common goal: to produce a safe building that affords a minimum level of protection to a trusting public. We must not view our individual expertise and specific role as being separate from the others, but strive to share our understanding of how our job relates to others and how it fits into the big picture. We must all understand the profound importance that our particular role plays in producing a building that will perform in the next earthquake.
Conclusion The purpose of the codes is to provide objective regulations that economically provide minimum levels of public safety in the built environment. We must strive to achieve this purpose through exemplary standards of quality and ethics in the design, plan review, inspection and construction process. Utilizing the most current code ensures that we are applying the latest technology to provide the highest level of safety in our built environment. We must work together as a cooperative team and recognize that we each play a vital role in the construction of buildings that will perform in the next earthquake, and be ever vigilant and realize that there will be a next earthquake.
1 Earthquake magnitude is measured by two methods. The first, known as Richter magnitude developed by Charles Richter at California Institute of Technology, is based on the amplitude recorded by a seismometer and gives a measure of the energy produced by the earthquake. The second method, called moment, is related to the slip and area of the fault and is a measure of the total energy release during the earthquake. The moment is then converted to generate a number similar to the Richter magnitude, which is called moment magnitude. 2 Recommended Lateral Force Requirements and Commentary, Sixth Edition, 1996, Seismology Committee, Structural Engineers Association of California, 555 University Avenue Suite 126, Sacramento, CA 95825. 3 NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, 1997, Building Seismic Safety Council, 1090 Vermont Avenue N.W. Suite 700, Washington D.C. 20005.
Building Code Effectiveness Grading Schedule by Dennis Gage, Insurance Services Officer Natural disasters have received increased attention in the 1990’s due to the severe impact they can and are having upon society. In one recent event, Hurricane Andrew, an estimated 61,000 residents in Dade County lost their homes due to the storm, and the work places of over half of those employed there were destroyed. In 1994, the Northridge Earthquake caused over 44,000 persons to be sheltered and almost 3,000 buildings to be declared unsafe for occupancy. The societal effects of catastrophes continue long after the event as individuals and communities undertake a rebuilding process. The consequences on the United States economy are also severe. The property/casualty insured loss alone for catastrophic events just since 1990 is over $48.4 billion. Unaccounted for in this figure are losses due to business interruption, unearned wages, government costs, uninsured losses and similar factors. The Federal Government has spent $38 billion in disaster assistance from 1990 to 1995. This equals $345 per taxpayer. The Federal Emergency Management Agency estimates that 75% of the nation’s housing stock sit in disaster prone areas, including 50 million homes at risk from earthquake. A significant portion of the property/casualty insured losses resulting from catastrophic events can be attributed to structures not adequately built to withstand the natural hazards inflicted upon them. Model building codes have been established which encourage, and often require, the latest natural hazard mitigation technology to be employed in the construction of buildings. However, even in instances where communities have adopted these model building codes, structures are not being built to adequately withstand natural hazards. Given that the model building code is important in building safe and sound buildings, the quality of the code enforcement process is even more critical. In 1992, a study was conducted in 12 coastal communities by the Southern Building Code Congress International (SBCCI). The purpose was to assess the knowledge of code officials on the wind resistant provisions in the codes. The study indicated that codes addressing the wind hazard were sufficient and the quantity of staff to enforce the code were above the average, but the building official’s knowledge of wind mitigation strategies contained within the codes scored less than adequate in both the plan review and field inspection functions. In fact, it was found that less than 33% of the building inspectors and plan reviewers could demonstrate adequate knowledge of wind-resistant construction. Another study conducted by a professor at Clemson University and a coastal engineer at North Carolina State University compared two similar hurricanes that impacted two similar coastal communities. The communities were Galveston Island, Texas (where Hurricane Alicia hit landfall in 1983) and Cape Fear, North Carolina (which was impacted by Hurricane Dianne in 1984). Both residential communities consisted primarily of elevated wood-frame houses in exposed, low-lying coastal areas. Both suffered hurricane winds between 80-90 mph. Hurricane Alicia destroyed 35% of the homes in Galveston Island, while the homes destroyed in Cape Fear by Hurricane Dianne equaled only 0.3%. One outstanding difference existed between the two communities — Galveston Island, Texas did not have a building code to guide developers/builders while Cape Fear enforced a version of the SBCCI Code. These studies reinforced the assumption that adoption of building codes which address natural hazards, and effective enforcement of these codes, would have a measurable impact on reducing damage to structures as a result of natural hazards. In May of 1992, the Insurance Institute for Property Loss Reduction (IIPLR) assembled representatives from academia, the three model building code organizations, state officials, local government officials and insurers to explore what the insurance industry could do to minimize the effect of natural disasters. The group concluded that, 1) communities need incentives to improve their codes and code enforcement practices, and 2) the insurance industry could benefit from a program that would assist underwriters by providing comparative information about the building codes and enforcement provisions in communities. The Insurance Services Office Inc. (ISO) has worked closely with membership and staff of the Natural Disaster Loss Reduction Committee of IIPLR and developed the ISO Building Code Effectiveness Grading Schedule (BCEGS). BCEGS is a grading system modeled after ISO’s long-standing public fire protection grading system. This grading system has a set of criteria against which a community’s building codes and enforcement will be measured. The result would be a classification on a scale of 1 through 10 with a grade 1 representing the most favorable conditions. BCEGS was developed with the advice of each of the three model building code organizations. In addition, the building code community at large was sent questionnaires on the proposed subject matters and weighting criteria. The content of the BCEGS reflects the recommendations of over 1,500 building officials who responded to the survey. Field tests on over 150 communities were conducted in Florida, North Carolina and South Carolina. The information gleaned from these test communities has also served to refine the Schedule into an effective evaluation tool. The grading schedule is designed to review a community’s building code enforcement efforts and adopted building codes with a specific focus to natural hazard mitigation. There are three main subjects in the BCEGS:
Like the plan review section, staffing levels, personnel experience, the extent of their field inspection and quality assurance programs are reviewed. The Schedule is a performance-based system with a total maximum point accumulation of 100 points. The score is translated into a grading scale of 1 to 10, with Class 1 being the most favorable classification. The classifications will then appear in an ISO insurer publication known as the Public Protection Classification Manual. This publication has an audience of over 110,000 insurers and agents. Insurers may then use these classification numbers to offer insurance premium discounts to all new construction within the graded jurisdiction. Over 2,500 building code enforcement agencies have been evaluated countrywide since the implementation of the program in 1995. It is projected that the balance of the building code enforcement agencies across the entire country will be visited by the end of the year 2000. Thereafter, communities will be re-graded every 5 years, or earlier upon notification of significant code enforcement changes within the jurisdiction. Administrative features of the BCEGS include: • The effective date of the BCEGS classification for a community will be based upon the year of the survey date. The BCEGS classification will apply to those structures that received a certificate of occupancy during the year of the effective date of the community grading and beyond. • If a community’s classification is revised (by virtue of a reclassification of the community), the revised classification will apply to structures receiving a certificate of occupancy during the year of the effective date of the revised classification and subsequent years. The BCEGS program effectively defines for insurers varying levels of community commitment to building code adoption and enforcement. In doing so, good public policy is recognized through insurance premium discounts being made available to property owners of new construction. The benefactors of this program extend beyond insurers to building officials, communities, property owners and Federal, State and local agencies as property losses are reduced through code compliant construction. Truly a win-win situation.
A Case History for Developing Positive Support for the Integration of a Seismic Policy Within a Community by Ron Lynn Clark County Building Department
When developing any regulations within a community, one must begin with caution as, historically, people are somewhat cynical about additional laws which govern what they can and cannot do, particularly ones which have the potential for the financial impact that seismic regulations can generate. Too often, there is an attempt to respond to the evidence of a disaster, rather than to use a methodical, strategic plan which allows for the evolution of new codes and standards with sufficient lead time to consider the various constituent groups within a community. The first step is to develop your goals and objectives, work on strategies and action plans, identify the technical, financial and emotional issues, which you will be dealing with. These variables must all be integrated into the culture of one’s community. How are laws in construction codes perceived, who are the primary movers and shakers who have the greatest credibility? Those regions with strong academic presence such as university towns can often find the leadership and impetus from the technical side. Other communities with more developed political environments need to recognize the challenges and realities of dealing with technical issues which are often not in the forefront of political concern. This is particularly true of disaster mitigation and preparedness. Disasters are by their very nature in the public consciousness for a relatively limited period of time. The community’s memory tends to be somewhat short and more urgent issues such as crime, pollution and schools, will push the relatively rare occurrence of an earthquake event from the forefront of their consciousness. It is incumbent upon those people interested in improving life safety codes to have plans fully in place when the opportunity arises. Therefore, the window of opportunity to strike with new regulations is often right after an incident occurs. Certainly, historical precedent exists. Regulations concerning unreinforced masonry, the problems with the connections on tilt-up construction, and most recently the issues regarding steel connections as a result of the Northridge disaster are all examples of reactive regulations initiated after disaster and tragedy have struck. Approximately three years ago, in an attempt to undertake a more proactive approach, Clark County, Nevada initiated a variety of regulation concerning the sub-surface environment. Clark County is in Zone 2-B with a number of faults and fissures, some of which have been classified as "active" in nature. The county encompasses the incorporated cities of Las Vegas, North Las Vegas, Henderson, Mesquite and Boulder City, as well as the unincorporated surrounding areas, with a total mileage of approximately 7900 square miles and a population in excess of 1.2 million persons. In the event of a disaster, we must be prepared to respond to the needs of our citizenry, as well as that portion of the over 30 million visitors per year who may be in town. Standards were developed regulating the minimum number and depth of borings, as well as types of tests, analyses, and reporting information. In addition, the problems with both fissures and faults were specifically identified, and with other geologic hazards, were incorporated on the Clark County Soil Guidelines Map, which is available to both professionals and the public. The map is on the local geographic information system, subject to ongoing review and update. This allows for continued modification as new information and additional detail is acquired The Southern Nevada Chapter of the Association of Engineering Geologists, with assistance from other scientists, recommended setback criteria. However the community, while sensitive to sound construction practices, rebelled at the idea of losing hundreds of feet on either side of a fault, and even further on a fault scarp zone for a recurrence rate which may be once in every 10,000 years or greater. After all, civilizations rise and fall in less periods of time. In lieu of that, Clark County has adopted the following code amendment: Section 1806.11 - Minimum Distances to Ground Faulting.
Further setbacks may be required if additional investigation on structures or pools indicates a higher degree of hazard potential. Critical structures, such as emergency response facilities and hospitals, are encouraged to consider additional setbacks during the design review process. Our approach is evolutionary in nature, and as ongoing paleoseismic and tectonic data become available the increase in setbacks, when justified, may be incorporated into the existing framework. This is accomplished much more easily as the community mind set has already accepted certain regulations that represent the "taking away" of valuable land. The adoption of codes for the mitigation of the structural effects of flood, earthquake and wind occurrences may appear initially to be daunting. Yet if the needs are there, the task is imminently doable. The greatest element in integrating disaster regulations and standards within a jurisdiction, whether proactive or reactive, is developing a sensitivity to the needs and culture of your community and then creating stakeholder groups, including code officials, engineers, public servants, the legal community, developers and, most importantly, the public at large. The opportunity for success is rather high, as evidenced by a variety of codes which have recently been adopted.
Earthquake
Safety Through Seismic Code Provisions: by Robert Olshansky Urban and Regional Planning, University of Illinois
We have all heard the old saying that it’s too late to close the barn door after the horse is gone. All too often this has been the case with building safety. Areas hit hard by natural disasters are quick to learn that 20-20 hindsight provides useful guidance for the future, but that it doesn’t help to mitigate the damage and disruption already sustained. Now a new guidebook published by the Federal Emergency Management Agency (FEMA) Mitigation Directorate makes an excellent case for early earthquake preparedness. The guidebook, entitled Promoting the Adoption and Enforcement of Seismic Building Codes (FEMA 313 Manual), is part of a larger effort to attract and support a group of advocates interested in promoting seismic building codes and their enforcement. Working with FEMA, the University of Illinois Department of Urban and Regional Planning is seeking to promote dissemination and active use of the manual by providing advocates with a free copy of the guidebook along with guidance on how to best use the material in the book for outreach initiatives. By adopting and enforcing seismic code provisions now, communities can help to ensure that new buildings are designed to standards appropriate to that area’s known level of seismic risk. Over time, as new building and infrastructure stock replaces older construction, communities will evolve with minimal cost toward a safer built environment. In other words, closing the barn door before the horse is gone.
Earthquake Risk & Preparedness Most parts of the United States are at risk for some amount of earthquake damage. Current known seismic risks for various areas are captured in the national seismic hazard map. One might suppose that existing code practices (adoption and enforcement) correspond to those risks. Not so, according to guidebook author Robert Olshansky, professor of urban and regional planning at the University of Illinois. Outside of the highest risk areas, such as California, the adoption of seismic code provisions has depended more on the efforts of concerned professionals than on the degree of actual risk. And once seismic code provisions have been adopted, communities need to invest in effective enforcement practices. A surprising number of areas have simply ignored this aspect of public safety. Other areas have instituted seismic codes but fallen short of effective enforcement.
Guidebook Contains Extensive, Practical Information The new guidebook brings together a tremendous amount of information about seismic risks and what various areas have done to incorporate seismic provisions into their building codes. For example:
FEMA perceived a need for a single publication that would give industry and community leaders and concerned officials the information and arguments they need to generate support for seismic code practices, noted Olshansky. Practical, concise, full of material that can be photocopied and distributed, the guidebook is an invaluable resource.
Advocates Encouraged to Volunteer as "Delivery Agents" The guidebook offers an ideal tool for building safety advocates—e.g., emergency managers, code officials and building safety staff, designers and constructors, insurers, planners, and civic leaders. It can be used to help deliver information to generate increased understanding and support for seismic safety. Suggested activities to help promote the adoption and enforcement of seismic codes include the identification of key groups, with subsequent presentations, workshops, press releases, articles, and/or legislative initiatives. Advocates who are interested in volunteering as "delivery agents" to implement these types of activities can obtain a free copy of the manual along with guidance on its use by contacting: University of Illinois,
The WSSPC Board of Directors is holding their June meeting in Sacramento, California, immediately following the Western United States Earthquake Insurance Summit. The Board will have a full agenda to address, including planning the WSSPC Annual Conference and the Tsunami Hazard Mitigation Symposium. Also on the agenda is a proposal to establish several new policy committees. The suggested topics of the three committees are: Insurance and Finance; Engineering, Construction, and Building Codes; and Critical Facilities, Infrastructure and Land-Use Planning. The new committees would be designed to review and generate policy recommendations for adoption by the full membership. The committees will be comprised of WSSPC Members and Affiliate Members, and will be an ideal forum for involvement from a broad cross-section of the seismic hazards reduction community. The Board is also looking into alternative means of communication for our membership. Because our region is so large, face-to-face meetings are often expensive. As a result, we will try to use the internet as a tool that enables our members to communicate and to collaborate on projects. A demonstration should be operating through our web site this summer.
WSSPC’s Changes: The Board of Directors would like to welcome Donald A. Hull, State Geologist from the Oregon Department of Geology and Mineral Industries. Dr. Hull was appointed by Lorayne Frank, Chair of the Board of Directors, to replace Dr. John Steinmetz as the third geoscientist on the Board. His appointment will be placed before the full membership at the Annual Conference in September. Dr. Steinmetz has taken a position as the State Geologist for the State of Indiana. We were informed George Meek is leaving his position as Earthquake Program Coordinator in Idaho. Stephen Weiser will be assuming these responsibilities. |
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| © 2006 Western States Seismic Policy Council. All Rights Reserved. Last updated April 16, 2007 |