"The earthquake risk in developing countries is large and growing rapidly. Unless something is done to reduce it, developing countries will suffer human and economic losses far greater than these countries have experienced in the past. Given the “shrinking” of the world, these losses will affect developed countries as well. GeoHazards International (GHI) is a Palo Alto-based, nonprofit organization that has attempted to reduce the death and suffering caused by earthquakes in the world’s most vulnerable communities, through advocacy, preparedness, and mitigation. Disaster response, recovery and reconstruction, which attract so much attention and resources after earthquakes strike, are not the work of GHI. Instead, GHI works before earthquakes to raise awareness, strengthen local institutions, and launch various mitigation activities, particularly in schools and hospitals. This is how to reduce death, suffering and economic losses. GHI and its partners around the world have achieved some success: because of our work, thousands of school children are safer, hundreds of cities are now aware of their risk, the seismic hazard of dozens of cities have been assessed, and numerous local organizations are more capable to manage their communities’ earthquake risk. But there is disturbing evidence that the rate at which earthquake risk management is improving, globally, is woefully inadequate. As GHI continues its work to improve risk management in developing countries, it has launched an effort to recruit new allies, such as the Rotary Clubs, for ideas and support." (Brian Tucker).
Brian Tucker received a B.A. in Physics, a Ph.D. in Earth Sciences from the Scripps Institution of Oceanography at the University of California, San Diego and a Masters in Public Policy from HarvardUniversity. He headed the Geological Hazards Programs of the California Geological Survey from 1982 to1991. In 1991, he founded GeoHazards International (www.geohaz.org), a nonprofit organization working to reduce the risk of natural hazards in the world’s most vulnerable communities through preparedness, mitigation and advocacy. He is currently a member of the Board of Directors of the Seismological Society of America. In 2000, he was honored for his service to the people of Nepal by the King of Nepal, and, in 2002, was named a MacArthur Fellow. In 2007, he received the U.S. Civilian Research and Defense Foundation’s George Brown Award for International Science and Technology Cooperation and was elected a Fellow of the California Academy of Sciences.
Breakfast with Brian Tucker and rotarians Steve Brown and Fary Moini of La Jolla Golden Triangle RC.
I am officially one of the 60 recipients of a Rotary World Peace Fellowship (link). "What do peace and international relations have in common with earthquake science and engineering structures?". How can a science background fit into international relations and development? This idea has developed in several conversations with different people from the Academia and the industry involved in earthquake engineering, and also many Rotarians from Italy as well as from San Diego. Among others, the work of Brian Tucker of GeoHazards International who is leading a passionate crusade against seismic disasters, has been extremely inspirational. I recommend reading this ARTICLE. The experience as a Rotary Ambassadorial Scholar in San Diego, stimulated my interest in humanitarian programs, and the Rotary leadership of District 2120 and District 5340 (thanks to Gaetano Laguardia, Riccardo Mancini and Vito Casarano, who encouraged and sponsored my candidature, and also to Philippe Lamoise and Donald Yeckel) made me find out about the program. This helped me think how modern earthquake engineering technology and international relations could work together towards global seismic mitigation.
Rotary District 5340 - Pathways to Peace committee
SETTING: The first conference and workshop held in New Orleans, January 11-13, 2007 and addressed the questions: should Rotary be involved in disaster relief and recovery and if so to what extent. The first question was a resounding yes, which set the stage for a more in depth addressing of the second question.
PURPOSE: At the conclusion of this workshop a participant will:
know the rudiments of the emergency management system;
know how to assess and determine in what areas of disaster operations a club should engage;
know how to organize their club to participate in disaster relief in their chosen areas of operation.
PRODUCT: At the conclusion of the workshop the participants will have the precursor to their club’s disaster operations manual (DOM).
March 2003 - ENEA Casaccia, Roma. Prof. Franco Braga recalls how the italian adventure of innovative earthquake protection started in Potenza, where he created a school of Earthquake Engineering at the University of Basilicata. From 1990 to 2000 he took the leadership in a project with the local government to train engineers on seismic retrofit of schools using energy dissipating braces, he designed and directed the construction of the base isolated buildings of the Unv. of Basilicata, and of the Rapolla building, subjected to an exciting campaign of "real" simulated earthquakes.
Italy, Basilicata region.
Basilicata, Italy. City of Potenza.
November 23 1980. Irpinia Earthquake.
Potenza, Piazza XIIX Agosto
Potenza, Bucaletto district, emergency housing for 700 displaced families. Potenza, UniBas, University of Basilicata, founded in 1982, two years after the earthquake.
UniBas Campus, completed in 1996. Five base isolated buildings host the faculties of Agricolture and Science. UniBas, Seismic Structural testing lab, completed 1997. Reaction wall for pseudodynamic tests and hydraulic systems functional in 2000 (courtesy M. Laterza).
UniBas, material and component testing lab. Static load test on rubber isolator device for the Rapolla building.
Rapolla, Potenza. Base isolated residential building for low income dwellings (design 1995, completed 2000). Subjected to full scale dynamic seismic tests (courtesy F. Braga, august 2000).
Rapolla, Potenza. Rubber base isolator (HDRB) placed between the structure and the foundation.
Rapolla, Potenza. Completed base isolated building and twin conventional (fixed base) building.
Potenza, Domiziano Viola school (my elementary school), retrofit with energy dissipating braces, completed 2002. The coloured braces act like "energy vampires" soaking up the earthquake energy that would otherwise damage the structure (courtesy F. Braga). Potenza, Domiziano Viola school (my elementary school), retrofit with energy dissipating braces, (completed 2002, courtesy F. Braga).
Potenza, School retrofitted with energy dissipating braces, completed 2006 (courtesy F. Braga).
Potenza, "G. Leopardi" School retrofitted with energy dissipating braces, completed 2006, (courtesy F. Braga).
Potenza, School retrofitted with energy dissipating braces, completed 2006.
"[...] The more I saw California successfully dealing with its [seismic] risk, the more I thought of the far greater risk abroad and the far fewer resources available there to address it. Over several years, the idea gradually grew in me to create a non-profit organization that would apply the science, engineering and public policy that had helped the U.S., Japan and Europe manage their earthquake risks to the world’s most vulnerable countries."
“[…] Why should the citizens of industrialized countries, distant from most earthquake threatened developing countries, care that there is a growing gap between the seismic risk of developing and industrialized countries and that not nough is being done?
[…] We should also care out of self-interest. We in industrialized countries understand that the growing gaps between rich and poor in our own countries led to social tensions. We can therefore realize that the widening of the gap between the industrialized and developing worlds is threatening. We will be more secure if all countries can develop without being periodically set back by natural disasters. It is in our economic self-interest, particularly, that developing countries become earthquake-resistant because they are increasingly important economic partners of the U.S., Japan, and the E.U. Often the infrastructure, residences, and factories of developing economies represent investments made by theindustrialized world. The North Atlantic Treaty Organization (NATO) also considers that helping developing countries manage their earthquake risk is in its self-interest. For example, NATO is organizing a workshop to address the problem of seismic risk of public buildings in the Maghreb Region (Tunisia, Morocco, and Algeria) because (1) NATO is in the business of stability, (2) mass migrations are destabilizing, and (3) natural disasters (such as earthquakes) cause mass migrations. NATO’s previous “Science for Peace” program is now known as the “Security through Science” program. […].”
"The recent earthquakes have again emphasized the fact that the major loss of life in earthquakes happens when the event occurs in developing countries. Even in relatively moderate earthquakes in areas with poor housing, many people are killed by the collapse of brittle, heavy, unreinforced masonry or poorly constructed concrete buildings. Modern structural control technologies such as active control or energy dissipation devices can do little to alleviate this, but it is possible that seismic isolation could be adapted to improve the seismic resistance of poor housing and other buildings such as schools and hospitals in developing countries". (J.M.Kelly).
RELIEF OR PREVENTION ?
“More effective prevention strategies would save not only tens of billions of dollars, but save tens of thousands of lives. Funds currently spent on intervention and relief could be devoted to enhancing equitable and sustainable development instead, which would further reduce the risk for war and disaster. Building a culture of prevention is not easy. While the costs of prevention have to be paid in the present, its benefits lie in a distant future. Moreover, the benefits are not tangible; they are the disasters that did NOT happen.” (Kofi Annan, UN Secretary-General: “Introduction to Secretary-General’s Annual Report on the Work of the Organization of United Nations, 1999").
SEISMIC ISOLATION
Seismic isolation is a construction method for protecting buildings, in which the building and ground are separated by an isolation system to limit the transmission of vibrations through the building. It reduces the earthquake force and changes it to a slow vibration, so not only the building, but also everything inside is protected.
Seismic isolation provides numerous benefits:
Safety improvement: Damage to not only the building itself but also interior facilities are restricted and gas or water leaks are prevented, as are secondary accidents due to falling furniture and human lives are protected.
Maintenance of function: The function of buildings can be ensured even after a major earthquake and life can continue as normal.
Protection of property: The difficulties of repair, reinforcement, demolition and rebuilding were experienced after the Great Hanshin Earthquake in Japan. Seismic isolation reduces concern.
Improvement of relief: Fear of earthquake can be alleviated and psychological burden is reduced.Evacuation route is secured after an earthquake.
Economic effect of seismic isolation: Considering safety improvements for disaster during an earthquake and reduction of repair costs after an earthquake, seismic isolation can reduce life cycle cost.
Increased flexibility: Earthquake input to building can be considerably reduced while design flexibility is increased. Precast construction method simplifies the whole structure including junctions and reduces weight of members.
An experimental project of seismic tests on a real building constructed at Rapolla, Potenza (PPT presentation), in Southern Italy demonstrated the effectiveness of base isolation in protecting low-income dwellings. For the application in developing countries the use of rubber devices together with the cheap sliding isolators (Hybrid Isolation) can bring two major advantages. It allows preventing any damage in the structure and control the vibrations even during a strong earthquake, and at the same time could make this technology particularly suitable for an economically sustainable use.
This video shows the construction progress, the placement of the isolators between the foundation and the base of the building, and the sequence of the seismic tests perfomed. (Courtesy F. Braga, M. Laterza).
During a strong earthquake the structure can move independently from the foundations, and undergo no damage. (Courtesy F. Braga, M. Laterza).
Due to the high flexibility of rubber isolators the structure is able to accomodate large movements while still carrying the vertical loads. In this way the impact of the earthquake is reduced through slow high amplitude controlled vibrations. (Courtesy F. Braga, M. Laterza).
The sliding isolator allows a better control of the movement, while still carrying the vertical load. The simple manifacturing process (a steel plate sliding against a PTFE pad) makes it particularly convenient for applications in developing countries. (Courtesy F. Braga, M. Laterza).
Jack-machine used to push the structure. (Courtesy F. Braga, M. Laterza).
COMPUTER SIMULATION. The seismic vibrations are simulated making a "virtual" test. Modern software tools allow engineers to create the action of earthquakes on a computer model of the structure. The dynamic behavior of the real building can be reproduced with good accuracy. These tools are extremely useful in the design of a new building or for the analysis and retrofit of a deficient existing one. Seismic building codes provide the engineering practice with guidelines and assistance in the design and in the use of analysis tools and software.
Study of Nonlinear Response of Base-Isolated Building through Large-Scale Free-Vibration Tests and Nonlinear Analyses
ABSTRACT
Base isolation is a technique adopted with success for the seismic protection of structures worldwide. Since the commonly employed isolation devices often exhibit a nonlinear behavior, laboratory tests are always needed to support both the design and the research. Various researchers have carried out extensive experimental studies on single devices or simplified reduced-scale structural models. Nevertheless, only experimental investigations with large scale structures can provide complete information on the real dynamic interaction between the isolators and the structural or non-structural system components. A base-isolated residential building located in Rapolla, South Italy, was subjected to free vibration tests with initial displacement amplitudes up to the design displacement of 18 cm. The tests have provided information on the nonlinear dynamic behavior of the whole building system under the design earthquake. A switchable HDRB-Slider isolation device was used to allow testing two different isolation systems having different nonlinearity. The experimental results have shown a modal energy exchange effect due to the nonlinear coupling of the modal responses in presence of frictional devices. The experimental response was reproduced by time history analyses using a nonlinear three-dimensional finite element model. The numerical analyses have pointed out the need for good model parameters for isolation devices based on dynamic tests, and the importance of accurate nonlinear time history analyses for capturing the higher-mode response of the superstructure. Further analyses under seismic action have shown that simplified procedures in some codes which neglect the nonlinear modal coupling could considerably underestimate the story shears in a building isolated with frictional or hysteretic devices.
F. Braga, M. Laterza, Field testing of low-rise base isolated building, Engineering Structures, Vol./Iss. 26/11 (2004) pp. 1599-1610.
F. Braga, M. Faggella, R. Gigliotti, M. Laterza, 2005. “Nonlinear dynamic response of HDRB or Hybrid HDRB-Friction Sliders base isolation systems” – Bulletin of Earthquake Engineering, Vol 3 n. 3, Springer editor.
F. Braga, M. Faggella, R. Gigliotti, M. Laterza, 2005. “Effetti delle non-linearità costitutive dei sistemi di isolamento sismico e metodi semplificati per la valutazione della risposta” – Ingegneria Sismica, Year 2005 Vol.2, Patron editor.