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Opportunities for NEES Research Utilization. Robert D Hanson Professor Emeritus University of Michigan. Who is responsible for adapting NEES research data?. The NEES researchers are responsible
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Opportunities for NEES Research Utilization Robert D HansonProfessor Emeritus University of Michigan
Who is responsible for adapting NEES research data? • The NEES researchers are responsible • Code committees and design professionals digest and adapt this data with active participation by researchers • This is done by active participation in code committees and professional activities by researchers
How can this be enhanced? • NEES research proposals should include input and recommendations by the expected users • NEES research efforts should included these professionals at the initiation, intermediate and concluding stages of the project • These professionals can help disseminate the applicable results to the design community
Research Priorities – How are they / should they be established? • NAE, EERI, BSSC, FEMA, NIST and material groups have identified research needs • Each has a recommended priority – with many listed at equal priority • A group of professionals and researchers without a vested interest in a specific research agenda should create a priority list for use by NSF proposal review panel use
Two examples of NEES Research Opportunities – How these projects identify priority needs • ATC 58 – Performance-based Seismic Design - Continuum of performance from small response [no damage], through various amounts of damage, to building collapse. Includes existing and new construction. • ATC 63 – Quantification of Building System Performance and Response – For use in new building design requirements to prevent life-loss.
Major contributors to the following are: • Mike Mahoney – DHS/FEMA • Ron Hamburger – ATC 58 Technical lead • Bob Bachman – ATC 58 NPP Lead • Craig Comartin - ATC 58 RMP Lead • Andrew Whittaker – ATC 58 SPP Lead • Eduardo Miranda - ATC 58 NPP team • Keith Porter – ATC 58 NPP team • Charles Kircher – ATC 63 Technical Lead
Building Code Process • Uses post-earthquake investigations, research information, professional judgment, and observed construction problems • Material standards are improved • NEHRP Recommended Provisions – Evaluation of new systems and major increments in knowledge • ASCE 7 – References material standards and uses input from NEHRP Recommendations as appropriate to update the current Standard • IBC and NFPA adopt ASCE 7 with or without modifications • Local and State Codes adopt IBC or NFPA with or without modifications
Building Code Process Observation of poor performance
Performance-based designA new approach SelectPerformanceObjectives DevelopPreliminary Design AssessPerformanceCapability ReviseDesign Does Does Yes Yes Performance Performance No No Done Meet Meet Objectives? Objectives?
Seismic Evaluation ofBuildings First Generation Procedures • Federal Emergency Management Agency sponsored a series of development efforts focused on existing buildings: • Evaluation guidelines • Predict types of damage a building would experience in future events • Rehabilitation guidelines • Procedures to design building upgrades to achievedesired performance ASCE-31
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Performance • The potential consequences of building response to earthquakes, including: • Life loss and serious injury (Casualties) • Direct economic loss (Cost = repair and replacement costs) • Indirect economic and social loss(Downtime = loss of use of damaged or destroyed facilities)
D t GroundMotion StructuralResponse Damage Performance Metrics:Casualties, Cost & Downtime Verifying Performance Capability All StepsRepresented On AProbabilistic FrameworkConsidering Uncertainty
Example building assessment – Moehle’s EERI Lecture : : : Height Area Occupancy 3 stories; 14 ft. floor 22,736 sq.ft. per Gene ral office space to floor; 42 ft total floor; 68,208 sq.ft. above grade; no total (actual building basement slightly larger)
Performance assessment procedure • Determine the hazard. • Analyze the structure. • Characterize the damage. • Compute the losses.
Exterior envelope 41% Contents (3rd flr. computer center) 25% Interior nonstructural (drift sensitive) 12% Interior nonstructural (accel. sensitive) 8% 5% Contents (Ist and 2nd flr. offices) 4% Structure 4% Roof top equipment 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% Portion of annualized capital loss Example design decisions
Fragility Functions Structural Response Parameters Structural and Nonstructural Damage (Engrg. Demand Parameters) Performance group fragility functions (Probabilistic Mapping Functions) • In order to establish fragilities it is necessary to establish a relationship between the building response and its associated damage
Loss of vertical carrying capacity DM3 DM2 DM4 DM1 First Visible Damage Wide cracks Punching failure Performance group fragility functions INCREASING INTERSTORY DRIFT
What Data is Needed? Protocol for data reporting • Description of the specimen(s) (Example based on research by Arnold, Uang and Filiatrault, 2002)
What Data is Needed? Protocol for data reporting • Description of the loading (Example based on research by Arnold, Uang and Filiatrault, 2002)
What Data is Needed? Protocol for data reporting • Detailed description of observed damage at each loading level IDR=0.34% (Example based on research by Arnold, Uang and Filiatrault, 2002)
What Data is Needed? Protocol for data reporting • Detailed description of observed damage at each loading level IDR=0.40% (Example based on research by Arnold, Uang and Filiatrault, 2002)
Interim Loading Protocols • FEMA 461 – Interim Protocols for Determining Seismic Performance Characteristics of Structural and Nonstructural Components Through Laboratory Testing – provides protocols for quasi-static cyclic testing of components and shake table testing of acceleration sensitive components
How will the data be used to generate fragilities? Six methods are proposed depending upon the data • Method A – all specimens failed at observed test levels • Method B – only some specimens failed • Method C – no specimens failed [qualification tests] • Method D – analytically derived fragilities without tests • Method E – expert opinion without test data • Method U – updating existing fragilities using new failure data or post-earthquake investigations
ATC 63 – Building Performance to Collapse current status • Planar analytical response of reinforced concrete moment frames, reinforced concrete shear wall buildings, timber townhouse and apartment buildings, autoclaved aerated concrete buildings, and steel moment frame buildings • Ibarra-Krawinkler degrading hysteresis model used for component behavior
ATC 63 – Building Performance to Collapse • Biaxial experimental data not available to perform 3-D dynamic response analyses • Limited full-scale building test data available for system performance calibration of analyses • Limited reduced-size building systems test data available • Very limited experimental data available to system collapse levels of deformation
Building Performance What can NEESR provide? • Sufficient archived data at all damage levels from no damage, through various damage states, to collapse. Include displacement-damage relationships and likely repairs needed for each level. • Multiple tests of similar specimens to establish reliability coefficients for the data. • Data on nonstructural components • Data on structural components • Data on systems of components
More information on projects and participation opportunities available at www.atcouncil.org