Earthquake Engineering Research Institute
Earthquake Engineering Research Institute
News Article | July 18, 2017
Base isolation is a method for moderating the effects of earthquakes on buildings. Isolator devices (either elastic or sliding) are installed between the foundation and the building superstructure. The accompanying slide show looks at the ten largest base-isolated buildings in the world, measured by total floor area. "The use of base isolation as seismic protection for buildings, bridges and industrial facilities continues to grow, but has done so more robustly internationally than in the U.S.," says Ronald Hamburger, Senior Principal with Simpson Gumpertz & Heger, a leading seismic engineering firm. Not surprisingly, Japan, the most seismically active country, employs it most extensively, with 4,100 base-isolated commercial and institutional buildings as of December 2015, according to the Japan Society of Seismic Isolation. "Japan looks at base isolation as a primary option," says Konrad Eriksen, President of Dynamic Isolation Systems Inc., a leading designer and manufacturer of isolators. "In the Japanese residential market, prospective condo owners will pay a premium for a base-isolated building compared to a conventional building," says Gordon Wray, associate principal at Degenkolb Engineers, another prominent seismic engineering firm. Turkey, another very seismically active country, is also firmly committed to base-isolation methodology. Notably, it has embarked on a $13.6-billion program to build numerous large modern hospitals, most of which will be base-isolated. In addition, major bridges and viaducts have also been protected in this fashion. One notable project under construction in Turkey is the Ikitelli Integrated Health Campus in Istanbul. The 2,330-bed main hospital building there is expected to contain 2,000 isolators. It is a public-private partnership being developed by Istanbul PPP Sağlık Yatırım A.Ş. When completed, it is expected to be the largest base-isolated building in the world. Other countries pushing base isolation include China, New Zealand, Chile, Peru, Colombia and Ecuador. In contrast, "in the U.S., seismic isolation is used relatively infrequently," according to Hamburger. "In recent years, the inaccurate perception that other structural systems, including energy-dissipated moment frames, or buckling-restrained braced frames, can provide similar protection at lower first cost has slowed the growth of this technology in the U.S." "In the U.S., seismic resilience is taken for granted because of the recent infrequency of earthquakes and several decades of good building codes," says Wray. "Modern buildings have performed well in recent earthquakes (few collapses), although we have not yet experienced a code-level earthquake in a densely populated area in 23 years. I believe that many building owners have an expectation of operational performance, when typical code buildings are designed only to protect life-safety." Seismic-isolation technologies fall into two categories: elastomeric and sliding systems. Elastomeric isolation systems consist of natural rubber; natural rubber with lead cores to dissipate energy; and high-damping rubber, consisting of blends of natural and synthetic compounds. Sliding systems generally include flat sliders, typically used in combination with elastomeric bearings and friction pendulum devices. Within the friction pendulum category there are a series of different designs, including the original system that employed a single curved dish and sliding element; a double pendulum, in which two curved dish surfaces are employed; and a triple pendulum employing three such surfaces. "The triple pendulum system reduces the size of the isolator while increasing its effectiveness," says Farzad Naeim, a prominent structural engineer and former president of the Earthquake Engineering Research Institute. Elastomeric bearings were first used on bridges in the 1950s and were found to be an improvement over mechanical bearings, which suffered from corrosion, according to Eriksen. Friction pendulum bearings were developed in the late 1980s. "Friction pendulum bearings dominate applications in the U.S., in some other important markets like Turkey, and most applications in certain types of structures worldwide (offshore oil platforms, LNG tanks, large bridges, hospitals)," says Michael Constantinou, professor of civil, structural and environmental engineering at the State University of New York at Buffalo. "Elastomeric systems perform best in large buildings, which have large axial loads," explains Wray. "Sliding systems perform well for both large and small axial loads (large and small buildings). The behavior of sliding systems under high-frequency vertical acceleration continues to be studied." Deformation in a building during a large earthquake is inevitable. "Using conventional lateral force resisting systems, the deformation is distributed up the height of the building among many beams, columns, connections, braces, or shear walls," comments Wray. In comparison, "using base isolation, (nearly) all of the building deformation is concentrated at the isolation plane, limiting damage up the height of the building. The magnitude of the displacement can be predicted with more certainty than the individual deformations among hundreds or thousands of individual components of a lateral system." "Of all the seismic protection technologies presently available, seismic isolation offers the most effective protection against damage or loss of function following strong shaking," says Hamburger. "Other structural technologies allow transmission of the motion into the structure, where its energy is dissipated either through damage to the structural elements, or through more benign energy dissipation mechanisms. Regardless, structures employing these other technologies experience greater motion and as a result more damage than do isolated structures." The evolution and spread of base isolation is influenced by many players. "Governments have played a role in funding research to develop these technologies, including Natonal Science Foundation-funded centers such as the Pacific Earthquake Engineering Research center at UC Berkeley and the Multidisciplinary Center for Earthquake Engineering Research at the State University of New York at Buffalo," says Constantinou. "Insurance agencies (and owners) have not yet taken into consideration the reduced risk of damage for a seismically isolated structure. This may change following the work of the U.S. Resiliency Council on rating building performance." The USRC membership includes all the major professional organizations in earthquake and structural engineering, structural engineering firms, architectural firms, contractors, and hardware and software suppliers. The USRC rating system rates buildings from one to five stars for each of three criteria: safety, damage and recovery. "While many lateral systems can provide high ratings for safety, base-isolated buildings provide the greatest opportunity to achieve high ratings for damage and recovery," says Wray. "The USRC will certify raters and review ratings after they are submitted, similar to the USGBC's LEED ratings for sustainability," says Ronald Mayes, USRC executive director and co-founder. "The rating is a different way of specifying what an owner's performance expectations are for a building. I think it will become a powerful tool." The rating system launched in December, 2015. One building has been rated so far, with 18 more in process, according to Mayes. "The structural engineering community in the past has done a poor job of communicating what a code-designed building delivers, as attested by the performance of modern buildings in the 2011 Christchurch New Zealand earthquake, where more than 50% of the modern buildings in the central business district delivered life-safety performance but had to be demolished after the earthquake," adds Mayes. "The Insurance industry has done little to encourage the use of seismic isolation, and it could be said that offering an earthquake mitigation alternative to developing earthquake-resistant structures, actually provides a disincentive," says Hamburger. "The primary insurance benefit the owner of a seismically isolated structure obtains is through an ability to purchase greatly reduced levels of protection. Some owners have chosen to use base isolation as their earthquake insurance of choice, as any damage that may occur is well below current deductibles. In addition, base isolation provides business continuity, something that is very difficult to cover with insurance." The order of the slideshow accompanying this article was updated on July 19, 2017 to reflect new information.
Ghosh S.,ImageCat Inc. |
Huyck C.K.,ImageCat Inc. |
Greene M.,Earthquake Engineering Research Institute |
Gill S.P.,The World Bank |
And 4 more authors.
Earthquake Spectra | Year: 2011
This paper provides an account of how the Global Earth Observation Catastrophe Assessment Network (GEO-CAN) was formed to facilitate a rapid damage assessment after the 12 January 2010 Haiti earthquake. GEO-CAN emerged from the theory of crowdsourcing and remote sensing-based damage interpretation and represents a new paradigm in post-disaster damage assessment. The GEO-CAN community, working with the World Bank (WB), the United Nation Institute for Training and Research (UNITAR) Operational Satellite Applications Programme (UNOSAT) and the European Commission's Joint Research Centre (JRC) led the way for a rapid Post Disaster Needs Assessment (PDNA) utilizing remote-sensing based analysis as the primary source of information for building damage. The results of the GEO-CAN damage assessment were incorporated into the final PDNA framework developed by the WB-UNOSAT-JRC and adopted by the Haitian government. The GEO-CAN initiative provides valuable lessons on multi-agency collaboration, rapid and implementable damage assessment protocols under extreme situations for the disaster management profession, developmental organizations, and society. © 2011, Earthquake Engineering Research Institute.
Ortiz M.,Earthquake Engineering Research Institute |
Comartin C.,CDComartin Inc. |
Greene M.,Earthquake Engineering Research Institute
NCEE 2014 - 10th U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering | Year: 2014
The Concrete Coalition is a network of individuals, governments, institutions, and agencies with a shared interest in assessing the risk associated with dangerous nonductile concrete buildings and developing strategies for fixing them. The Concrete Coalition received funding support from the U.S. Geological Survey to build a database from past earthquakes that illustrate deficiencies contributing to collapse of concrete buildings. In addition to photographs, the database has been populated with information from particular buildings, including sketches, drawings, and information on retrofit. The result is an online database of concrete buildings damaged in earthquakes with information drawn from a wide variety of published sources compiled by summer interns with the guidance of mentors from structural engineering firms around the world. As this database is further populated, it will be able to help analysts understand the relative importance of deficiencies with respect to collapse and performance more generally.
Ortiz M.,Earthquake Engineering Research Institute |
Rosinski A.,California Geological Survey |
Greene M.,Earthquake Engineering Research Institute
NCEE 2014 - 10th U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering | Year: 2014
The California Clearinghouse is a consortium that facilitates coordination of post-earthquake field investigations and shares observations and knowledge among the scientific, engineering and emergency response communities after a damaging California earthquake. The Clearinghouse is managed by representatives from five core groups: the California Geological Survey (CGS), the U.S. Geological Survey (USGS), the Earthquake Engineering Research Institute (EERI), the California Office of Emergency Services (CalOES) and the California Seismic Safety Commission. Since the Clearinghouse was established in 1972, there have been more than 10 Clearinghouse activations. The last major clearinghouse activation was after the Northridge earthquake in 1994. Since that time, technology has advanced greatly. The static map with pins has been upgraded to a dynamic GIS map with markers, geospatial overlays, and zoom capabilities. The large datasets associated with these maps require a new way of thinking about data after a disaster. Having protocols for collecting and sharing data, before the next earthquake, is essential. As the contact point for researchers and scientists after a California earthquake, the California Clearinghouse is taking the lead in California to develop a concept of operations for a virtual (online) clearinghouse through a series of technological demonstration exercises.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 43.82K | Year: 2011
This Grant for Rapid Response Research (RAPID) award provides funding to send a small team of researchers to address several focused questions arising from the magnitude 6.3 earthquake which struck Christchurch, New Zealand, at 12:51 p.m. local time on February 22, 2011. This earthquake was an aftershock of the magnitude 7.1 September 3, 2010 (UTC) earthquake, but because of the time of day, the shallow depth of the earthquake and its closer proximity to the city the infrastructure damage, economic impacts and casualties are much greater than from the main shock of September 4, 2010. It is rare for a modern infrastructure inventory to be shaken by two strong and damaging earthquakes -- a major event followed by another at the same place within a six-month period. It is essential to explore this pair of events so that the research aspects of this rare concurrence will not be overlooked. The team will be tasked with addressing specific questions, and keeping an eye open to research opportunities not yet recognized, so that it can report back to the US research community in a timely fashion, thereby facilitating subsequent research as may be proposed by the US research community. In this project, three research themes have been identified as critical issues in need of immediate investigation before ephemeral data is compromised or lost. The focused reconnaissance themes that will be investigated are: Building collapse; Use of social media and risk communication; and Community resilience.
This study has an explicit goal to broaden participation in the earthquake reconnaissance process as much as possible, engaging younger and underrepresented community members to participate on the team. In addition, this study addresses two of NSF?s broader goals: to promote US leadership in science and engineering, and to build longer-term international collaboration. The findings from the reconnaissance investigations will be shared widely with the broader research and practicing earthquake engineering community. The deliverables include contributions to a summary report that will be published in the Earthquake Engineering Research Institute (EERI) newsletter, research summaries immediately posted on the web and shared with the community, a webcast briefing with Pacific Earthquake Engineering Research Center at the University of California, Berkeley and the EERI/George E. Brown Network of Earthquake Engineering Simulation webinar on these research themes.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 240.00K | Year: 2012
Urban centers worldwide are threatened by earthquakes. The effects of an earthquake on a community depend on the magnitude and location of the earthquake as well as on how well the community has planned for the future earthquake. Community resiliency to an earthquake depends on the capacity of individuals, households, businesses, and region to survive and to recover after a disaster strikes. The best lessons for earthquake resiliency can be obtained by the study of what worked and didnt work in regions that are struck by earthquakes. This proposal will design and conduct a focused earthquake reconnaissance effort to accelerate learning about seismic resiliency, such that a significant leap in knowledge can be made. The proposed research effort builds on the acclaimed multi-decade and multi-disciplinary EERI Learning From Earthquakes (LFE) program, but it proposes a major change and refocus of the LFE program to achieve the target result of superior understanding of community resiliency.
A multidisciplinary Seismic Resilience Panel will guide earthquake reconnaissance to maximize resilience learning relevant to the U.S.; to conduct post-earthquake reconnaissance efforts focused on seismic resilience; to develop methods for systematic data collection, archiving, and dissemination of the findings; and to prepare a synthesis report summarizing the principal findings of the project. The intellectual merit of the proposed program lies in (a) defining the key physical and human elements that contribute to, or inhibit, seismic resilience in U.S. communities, and (b) exploring those elements through focused earthquake reconnaissance in the U.S. and worldwide, as appropriate. In the process, better understanding of the physical, social, economic, governance and institutional factors that facilitate or slow recovery will be achieved. By understanding these complex conditions and their interactions in the post-disaster environment, the grand challenges that need to be addressed will emerge. Through the solution of these challenges advancement in resilience knowledge will be gained. The ultimate goal is to improve the seismic resilience of communities in advance of disasters.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 49.00K | Year: 2011
The objective of this award is to organize and conduct a workshop for NSF-supported Rapid Response Research (RAPID) awardees to identify themes and directions for research programs resulting from their investigations of the 2010 and 2011 New Zealand earthquakes and the 2011 Japan earthquake and tsunami. The two-day workshop will be held at the National Science Foundation in Arlington, Virginia, in 2012. Workshop participants will identify major lessons and opportunities for further research across a range of disciplines, including topics that are cross-disciplinary in nature. Recommendations from the workshop will be shared widely with the broader research and practicing earthquake engineering community in a workshop report disseminated through the Earthquake Engineering Research Institute (EERI) website (http://www.eeri.org) and EERIs monthly newsletter. This award is part of the National Earthquake Hazards Reduction Program (NEHRP), and the workshop report will also be posted on the NEHRP web site (http://www.nehrp.gov).
The New Zealand and Japan earthquakes and tsunami present major learning opportunities for the U.S. research community. The complex nature of these events and resultant disasters provide major lessons and research opportunities across many disciplines. These recent earthquakes and tsunami are among the most significant and relevant events for the U.S. earthquake engineering community in the last several decades. Building codes in both countries are similar to those in the United States for concrete and steel buildings; there are many strong motion records (especially in Japan) that provide valuable data; the geologic setting and tsunami vulnerability for Japan are similar to the Pacific Northwest Cascadian subduction zone; there are similarities and lessons from the transportation, lifelines, and critical facilities sectors; and there are similar social and political issues in the response and recovery. This workshop will provide the mechanism to collect and synthesis observations from the numerous NSF-supported RAPID field studies to identify research needs for earthquake mitigation, preparedness, response, and recovery to make the United States better prepared for future disasters.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 30.00K | Year: 2010
This award provides travel support to China for five U.S. academic researchers and two Earthquake Engineering Research Institute (EERI) representatives on the twenty-one member U.S. team to participate in the first China/USA Symposium for the Advancement of Earthquake Sciences and Hazard Mitigation Practices. This symposium is in response to a request from the President of the Chinese Academy of Sciences to conduct a joint scientific exchange on earthquake hazard mitigation with invited U.S. expertise. The one-day symposium in Beijing, China and two-day field trip to the epicentral area of the 2008 M7.9 Wenchuan, China earthquake will be held from 19 to 21 October 2010. Two days of informal meetings with key Chinese government agencies and researchers working in earthquake-related fields will be held during the week of the symposium/field trip. The symposium/field trip is co-sponsored by EERI and the Chinese Chamber of Commerce of Hawaii. EERI will administer the travel grant, coordinate travel arrangements, and handle all administrative procedures involved.
Broader Impacts: The symposium will advance earthquake sciences and hazard mitigation practices in both China and the U.S., establish a baseline of state of the art earthquake engineering practices, and identify areas for future research of common interest, while enhancing cooperation and mutual understanding between the two countries.
Intellectual Merit: In this symposium, expert earthquake scientists, engineers, and hazard mitigation practitioners from China and the U.S. will meet and collaborate to identify and discuss the approaches and research taken by both countries to address common issues in earthquake hazard mitigation. This first meeting will help identify areas of future research and facilitate a continuing exchange of useful scientific, engineering, and planning knowledge and experience that could lead to safer buildings and reduced casualties in future earthquakes. The symposium and related meeting functions enable a multi-disciplinary team from the U.S. to interact with a very broad range of Chinese officials and researchers in the key ministries, universities, and institutes dealing with earthquake research, development of codes and standards, planning, hazard mitigation, and disaster response and recovery policies.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 58.00K | Year: 2010
This award provides support for two workshops to identify emerging themes and directions for potential research resulting from the magnitude 7.0 January 12, 2010, Haiti earthquake and the magnitude 8.8 February 27, 2010, Chile earthquake. These two earthquakes are among the top five earthquakes in recorded history in terms of number of fatalities and magnitude size. The Earthquake Engineering Research Institute (EERI) will organize these workshops to explore needed research and data gathering opportunities from these two major seismic events. EERI has a long and successful history of organizing workshops following major important earthquakes. EERI staff will organize, plan, and manage the workshops, and then prepare and disseminate reports summarizing workshop results and research recommendations. Both the Haiti and Chile earthquakes present major learning opportunities of different types for the U.S. engineering and scientific communities. The Haiti earthquake has research lessons emerging from the response and rebuilding. The complex and devastating nature of that disaster will shape these lessons across many disciplines. A different set of research needs and lessons will emerge from Chile, which is one of the most significant earthquakes for the U.S. earthquake engineering community in the last several decades. Building codes in Chile are similar to those used in the United States for concrete and steel buildings; there are strong motion records that provide important data; the geologic setting is similar to the Pacific Northwest; there are similarities and lessons from the transportation, lifelines, and critical facilities sectors; and there are similar social and public policy issues in the response and recovery. The workshop on the Chilean earthquake will be held at the National Science Foundation (NSF) in Arlington, VA, on August 19, 2010; the workshop on the Haitian earthquake will be held at NSF on September 30-October 1, 2010. Each workshop will be led by an organizing steering committee and include participants who conducted post-earthquake investigations for the event through NSF-supported RAPID or similar awards, and invited collaborators from the affected country.
Objectives and Broader Impacts: The objective of these two workshops is to identify major research themes and directions emerging from the 2010 earthquakes in Haiti and Chile. Workshop participants will identify these directions to guide NSFs programs for future research related to these events. Participants will define major lessons and opportunities for further research across a range of disciplines, including topics that are multi- and cross-disciplinary in nature. Transformative and cross-cultural research areas will be identified, where appropriate. Recommendations from these two workshops will be shared widely with the broader research and practicing earthquake engineering communities through EERIs clearinghouse website (http://www.eeri.org), EERI newsletter, and NSF (http://www.nsf.gov) and NEHRP (http://www.nehrp.gov) websites.
Intellectual Merit: These workshops will draw on world-recognized experts in a wide range of disciplines related to earthquake and disaster research, mitigation, response and recovery. Their interaction and synergy in the workshops will result in an intellectually rigorous set of recommendations for future research that identifies opportunities for linkages across disciplines and topics, and clearly illuminates the most important directions for research emerging from these major earthquakes.
This award is co-funded by the Division of Civil, Mechanical and Manufacturing Innovation and the Division of Chemical, Bioengineering, Environmental and Transport Systems and is part of the National Earthquake Hazards Reduction Program (NEHRP).
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 45.00K | Year: 2011
The 11 March 2011 magnitude 9.0 Tohoku, Japan earthquake, with its ensuing tsunami, surprised many in the research and practicing professions. An earthquake of this size was not anticipated; the Japan Trench subduction zone had been assumed capable of a magnitude 8.0 earthquake but not much greater. Early reports indicate the constructed environment survived the ground shaking reasonably well given the magnitude of the event. However, the tsunami overpowered coastal defenses and caused wide-spread devastation along Japans northeast coast. This event is an important learning opportunity for U.S. researchers due to (1) the many similarities between this event and a possible Cascadia subduction zone earthquake and tsunami that could affect western U.S. coastal communities and (2) the paucity of knowledge currently available on the effects of a catastrophic disaster in a developed country with many engineered structures designed or retrofitted for earthquake loads. The U.S. and Japan are both highly industrialized and advanced economies with many commonalities in their built infrastructure. This Rapid Response Research (RAPID) award builds on the Earthquake Engineering Research Institutes (EERI) long-term relationships with Japanese researchers and practicing engineers to organize the rapid collection of perishable data and early field reconnaissance from this 2011 event as a fully collaborative effort. Researchers supported on this award will team directly with respective Japanese colleagues to undertake field investigations followed by jointly authored reports. The primary collaborating organizations are the Architectural Institute of Japan, the Disaster Prevention Research Institute at Kyoto University, and the Japan Association for Earthquake Engineering. Three research themes have been identified for the rapid collection of perishable data: transportation systems, particularly bridges; engineered buildings, including the large inventory of retrofitted structures and use of modern technologies such as base isolation; and government and community response, in the areas of emergency response, social capital, institutional frameworks, and rebuilding, for a disaster of this extraordinary scale and complexity.
The data from this reconnaissance will be used to advance knowledge in seismic bridge retrofit and design requirements; seismic performance of structures with protective systems and concrete and steel buildings; and resilience, response, and recovery for a catastrophic event. Findings from the reconnaissance investigations will be shared widely with the broader research and practicing earthquake engineering community through EERIs clearinghouse web site, short research summaries posted on the clearinghouse and in inserts to the EERI monthly newsletter, and a web cast.