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Seismic Performance in Urban Regions (SPUR): A Simulation Example. Roger L. King Tomasz Haupt Mississippi State University Gregory L. Fenves University of California, Berkeley Jacobo Bielak Carnegie Mellon University Joerg Meyer University of California, Irvine.
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Seismic Performance in Urban Regions (SPUR): A Simulation Example Roger L. King Tomasz Haupt Mississippi State University Gregory L. Fenves University of California, Berkeley Jacobo Bielak Carnegie Mellon University Joerg Meyer University of California, Irvine NSF NEES Awardees Meeting September 11-12, 2003
Outline of Presentation • Roots of project • What is SPUR? • Value of integration • Structural performance • Earthquake ground motion modeling • City response • Visualization • SPURport – web portal • Future plans • SPURport demo
SPUR, a Distributed Simulation Framework for Seismic Performance for Urban Regions • Advance the state-of-the-art in simulating the effects of a major earthquake on an urban region. • Integration of earthquake ground motion modeling with modeling of structural and infrastructure systems using advanced computational and visualization methods • Shift focus from a discipline specific approach to a problem centered approach.
SPUR, a Distributed Simulation Framework for Seismic Performance for Urban Regions • A distributed interactive simulation framework will be created to facilitate investigation of the performance of urban regions resulting from a major earthquake and for the education of future earthquake engineers. • The goal is to develop tools that will ultimately permit damage estimates based on best available information. • This can lead to earthquake related risk analysis/assignment for an urban region and to provide a rich problem solving environment for the education of students.
Basin Effects Middleware Systems-level Applications • Loss estimation • Tools for decision makers • Scenarios for planning Planning Microzonation Education Emerg. Resp. Loss Estimate Enabling Technologies • Archimides • OpenSees • NEESgrid • System integration Viz HPC Resource NEES Fundamental Research • Computational seismology • SSI with DRM • PBEE Performance measures • Spatial distribution of performance • Large scale viz. SSFI Large Scale Viz PBEE SPUR Strategic Vision
System Architecture ground motion data (CMU) precomputed simulations structural response (Berkeley) precomputed or online simulations rendering + portal(UCI) (MSU) immersive rendering &web-based portal
SPURport: The Grid based portal for SPUR • Provide earthquake community with collaborative environment for research on Seismic Performance of Urban Regions and training of future earthquake engineers. • Develop NEESgrid application of databases, computation, visualization, using distributed Grid-accessible resources; demonstrate ability to use NEESgrid resources at any location • Opportunity to apply NEESgrid software releases to a substantial application and provide NEESgrid developers feedback • Add to simulation capability of NEES
SPURport Prototype • Development begun summer 2003 • Design and rapid prototyping iterations • Extensible as SPUR functionality increases and NEESgrid matures • Coordinate future SPURport development with NEESgrid roadmap
Strike slip Fault Simulation Model Peak Ground Displacement Peak Ground Velocity
Thrust Fault Simulation Model Peak Ground Displacement Peak Ground Velocity
SDF Model u u u u u u u u Grid point Building Models Structural Models for Regional Simulation ObjectiveEvaluate regional distribution of Engineering Demand Parameters (EPD) • “Hydra” model • Multiple parameters and multiple orientations • Constant strength analysis • Constant ductility analysis ShearBeam Model GeneralizedFrameModel Building Models Simulation Tool – OpenSees (PEER software framework for simulation)
Distributed Plasticity Beam-Column Column Fiber Section Leaning columnsfor P-D effects Beam Fiber Section SAC 9 story OpenSees Model LA 10%/50 year
Roof drift ratio Max Story Drift Ratio Max Plastic Rotation PGV Regional Distribution of SAC 9 story EDP
Roof drift ratio Max Story Drift Ratio Story 22 Story 15 PGV Regional Distribution of SAC 20 story EDP Max Plastic Rotation
Pushover Analysis of Frame Model Shear Beam Model Story Force-Deform. Calibration of Shear Beam Model
Rotational Spring SAC 9-story Building MBi Mpi= 2SMpij Mpi All rotations at joints lying at each floor level are identical Myi KBi= 2SKBij qi KBij= 6EIBij/Lj MBi= KBiqi Column Column is modeled using elastic beamwith plastic hinge with hinge length KCi= SKCij M j Calibration of Generalized Frame Model
Comparison of Floor Displacement Shear Beam Model Floor 1 Floor 2 Floor 3 Generic Frame Model Floor 1 Floor 2 Floor 3
Comparison of Story Drift Shear Beam Model Story 1 Story 2 Story 3 Generic Frame Model Story 1 Story 2 Story 3
Regional Distribution of EDP, 3-Story Roof Displacement SAC Frame Model Shear Beam Model Generic Frame Model Max Story Drift SAC Frame Model Shear Beam Model Generic Frame Model
Constant Ductility Analysis • 28 parameter combinations. • Considering 8 orientations. • 25,281 grid points. • 5 iterations in average. • One million non-linear analysis • of SDF system per parameter. Computational Challenge SAC 9-Story Simulation • 306 DOFS, 1800 time steps. • Approx 4 min. per grid point. • 25,281 grid points. • 70 days in single processors.
Steal work load NFS servers Steal work load Master node output work size Parent nodes data output data Child nodes data result NFS servers Steal work load Steal work load Parallel Computation Approaches • Use MPI in distributed memory system (e.g. Linux cluster). • Dynamic load balancing essential for even finish time with various load conditions on multiple processors. • Two approaches developed for hardware architectures and regional simulation problems. Producer-Consumer Approach Stealer Approach
Producer-Consumer Approach Master Node Slave Node Ground Motion Data wake ProcessManage Job Queue Receive Ground Motion Un-packaging Structure parameter Wait Queue Send Ground Motion packaging Structure parameter OpenSeesFramework Model Domain Un-packaging Receive output Recording output Pattern Material Element Packaging Send output Solution Procedures Analysis wait OpenSees Applications for Parallel Computing Parallel simulation applications built with OpenSees API and MPI API can be implemented using NEESgrid resources.
Depth (km) Rupture Model Wald et al. (1996) Strike=122 (S58E), Dip=40 (S32W), Rake=101 USGS
Snapshots of surface velocity Peak ground velocity (USGS)
Verification against other codes-Graves (URS)- Archimedes -Quake
IDEALIZED MODEL Cross Section Reduced Domain Cascading (3 models)
Analysis Region Observation Point (1280, 3000) FREE FIELD RESPONSEPeak values of displacement and velocity
Observation Point Velocity (m/s) |FT|
Peak Ground Velocity in Region of Interest Vmax 800 m/s 40 m 200 m/s 100 m/s
Influence Of Different Structural Distributions On Maximum Ground Velocity (EW) R-City 3 1.0-Hz Buildings Free-field
Notation for SSI 57 44
SSI Analysis of Three Building Groups for the R-City Simulation (EW Displacement)
Maximum Velocity Response EW NS 1.0-Hz City buildings 2.0-Hz City buildings R-City buildings
Visualization New Algorithms: • TetFusion • Efficient 3-D mesh decimation • More efficient than edge-collapse • Various levels of detail • Controlled Fusion • Metric 1: local scalar attribute error • Metric 2: accumulated scalar error • QTetFusion • QuadMetric: • Metric 3: topology preservation
ERC at Mississippi State PSC NCSA OpenSees Ground Motion Data OpenSees Ground Motion Data Struct. Resp. Data SPURport Architecture NEESpop (middleware) Front End NEESgrid services Data streaming andchannel management Data Controller Data Tele-presence Authentication and authorization Data and Metadata SPUR applet Collaboration OGSI (globus 3.0) Apache Tomcat JetSpeed Chef NSDS MSU extensions (Enterprise Computational System) ECS application streaming device driver Request DBMS (postgress) EJB container (JBoss) Back End
EQModel PopulationMethod (inventory) RegionalSimulation StructModel Spatial Quantity SpatialResponseData SPURport Data Objects EQVolumeData GroundMotionData association (has a ….) composition (contains a ….)
Earthquake Model Structure Model Inventory of Structures select or define a structure (set parameters) select or define an inventory view data select location extract data run simulation run simulation (future) view data view data SPURport functionality