Preventing Earthquake Disasters: The Grand Challenge in Earthquake Engineering A Research Agenda for the Network for Earthquake Engineering Simulation (NEES) (2003) / Chapter Skim
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3. NEES and Grand Challenge Research
3. NEES and Grand Challenge Research
Pages 63-83
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From page 63... ...
As such, NEES represents a new and ambitious approach for carrying out the research vital for vastly accelerated improvements in the seismic design and performance of the built environment, in the United States and around the world. However, there is also a deeper sense in which NEES will affect the course of earthquake engineering research.
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From page 64... ...
consortium have revolutionized seismological research. The IRIS activity demonstrates that the value of experiments increases dramatically if the setup and results are carefully documented and the resulting data are shared and used by the larger scientific and engineering community.
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From page 65... ...
The long-term goal of ultimately preventing earthquake disasters can become a reality through a concerted, unified effort by the entire earthquake engineering community working together with policy makers, government officials, and others.
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From page 67... ...
On this basis, the committee presents six research ideas that it believes would be ideal for initial NEES efforts. These ideas would take advantage of the abilities of multiple NEES equipment sites to address the many interwoven technical issues in earthquake engineering and to offer ample opportunities for multidisciplinary collaboration and synergy, and they could provide enormous paybacks over time.
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From page 68... ...
Although great strides have been made in the last two decades to improve our predictive capabilities and seismic engineering design practices, there remains an urgent need for more robust modeling procedures and predictive tools, more powerful site characterization techniques that provide improved parametric input data for numerical models, and more quantitative guidelines for soil improvement measures. Researchers need to validate the current liquefaction susceptibility mapping techniques so that they truly delineate the zones that liquefy during an earthquake.
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From page 69... ...
Convincing Loss Prediction Models to Guide Zoning and Land Use Decisions The magnitude of an earthquake-induced loss is heavily dependent on the size of the event and the quality and strength of the structures and facilities it impacts. Because there is little that can yet be done to control naturally occurring events, most earthquake mitigation measures have been directed at the built environment.
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From page 70... ...
of service. Hazard mitigation for lifeline infrastructures such as water, electricity, and communications has generally focused on first-order effects designing the systems so they do not fail under the loads imparted by earthquakesand NEES can make an important contribution to the testing of physical behavior of components and systems as a result of ground shaking, ground failure, etc.
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From page 71... ...
For example, the coupled simulation of strong ground motion, soil behavior, and structural response is now possible. The ability to work through the many permutations of earthquakes, soil types, and foundation designs for various building types will be invaluable for site assessment, performance-based seismic design, damage prediction, and loss estimation.
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From page 74... ...
Having acquired a thorough understanding of the time' effoft, skills' and expertise required to run NEES experiments the new faculty member Is able to assist f4t4re graduate students. / lion between the soil, the foundation, and the structure during the passage of seismic waves can cause partial weakening or failure of the soil surrounding the foundation; rocking, torsion, and translational motion of the foundation; and energy dissipation in the soil due to the shaking of the structure.
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From page 75... ...
for a given earthquake or, more realistically, on modeling waveforms explicitly from first principles of physics, using earthquakes on potential causative faults. Geotechnical engineers need to evaluate the response of the site to the incoming seismic wave motion, including potential nonlinear behavior of the local soils, site amplification, and the effect of the resulting ground motion on the foundation.
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From page 76... ...
Hybrid Simulation Systems for Numerical, Laboratory, and Field Modeling Arrays of physical tests interactively connected with computer models in a hybrid simulation concept would provide real-time stress-strain data to numerical, laboratory, and field models of real systems such as natural soil deposits, structures founded on soils, earthen structures, and
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From page 77... ...
For the first time it will be possible to fully elucidate the interaction effects on soilfoundation-structure systems during earthquakes and thus help to determine when these effects are beneficial and when they are deleterious to the performance of the structure and its foundation. Predicting Building Response to Damaging Earthquakes The Challenge With the growing emphasis on performance-based seismic design, there is a need to develop a comprehensive understanding of the earthquake response of a building when damage occurs in the structural sys
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From page 78... ...
. NEES can help to create a comprehensive body of research data and can develop convenient computer analysis tools that support the reliable and routine analysis of progressive earthquake damage in buildings and assess the influence of damage on the seismic response of buildings.
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From page 79... ...
The work products of each participant would be clearly defined, and these work products would be coordinated, leaving no significant knowledge gaps at the completion of the program. A partial list of coordinated research activities at NEES equipment sites follows: · Three-dimensional testing of lightly reinforced concrete beam-column joints, normally reinforced concrete beam-column joints, and welded steel moment frame joints, supplemented with numerical simulations and software module development.
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From page 80... ...
This could be supplemented with real-time teleobservation of actual shake-table tests at the NEES equipment sites, direct access to NEES researchers through e-mail, teleconferencing, and Webcasts, and teleoperation and observation of a model shake table maintained at one of the NEES sites. All participants would contribute to a coordinated set of core software elements that would form (perhaps through additional commercial development)
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From page 81... ...
· Adoption by public authorities, owners, and investors of recovery simulation and planning techniques that lead to prompt restoration of economic and societal activities and to reduction of the risks of future earthquakes. The Role of NEES NEES equipment sites will allow generation of earthquake motions to determine the performance of structures and verify mathematical models for the simulation of structural performance.
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From page 82... ...
Simulations of the effects of earthquake damage on the social and economic functions of a city also can be used to guide recovery operations and investments. Decision aids to help officials decide which buildings and lifelines to repair, and in what order, will be based largely on functional, social, and economic modeling, which are not directly dependent on research at NEES equipment sites.
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From page 83... ...
Of even greater importance will be the education and training of the next generation of earthquake engineering talent (see Sidebar 3.2~. The unique and exciting opportunity presented by NEES is the ability to address complex problems that cut across multiple disciplines and can involve multiple equipment sites and researchers and analysts from around the world truly a new paradigm in earthquake engineering research.
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