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EARTH SCIENCE ASPECTS OF HAZUS. Ivan Wong Seismic Hazards Group URS Corporation Oakland, CA. HAZARDS CONSIDERED IN HAZUS. Ground Motion Ground Failure Liquefaction (Settlement and Lateral Spreading) Landslide Surface Fault Rupture Tsunami / Seiche. SOURCES OF GROUND MOTION INPUT IN HAZUS.
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EARTH SCIENCE ASPECTS OF HAZUS Ivan WongSeismic Hazards Group URS CorporationOakland, CA
HAZARDS CONSIDERED IN HAZUS • Ground Motion • Ground Failure • Liquefaction (Settlement and Lateral Spreading) • Landslide • Surface Fault Rupture • Tsunami / Seiche
SOURCES OF GROUND MOTION INPUT IN HAZUS • Deterministic Analysis (Scenario Earthquakes) • User specifies location and earthquake magnitude • WUS fault, historical epicenter, or arbitrary epicenter • USGS National Probabilistic Hazard Maps(500 and 2500 yr maps) • User-Supplied Deterministic or Probabilistic Hazard Maps
CALCULATION OF SCENARIO GROUND MOTIONS IN HAZUS • Select scenario earthquake • Use rock attenuation relationships • Standard shape of response spectra (pga, pgv, 0.3 and 1.0 sec SA) • Amplify rock ground motions using 1997 NEHRP Provisions
WESTERN U.S. ATTENUATION RELATIONSHIPS IN HAZUS • Boore et al. (1993; 1994) • Sadigh et al. (1993) • Campbell and Bozorgnia (1994) • Munson and Thurber (1997) - Hawaii • Youngs et al. (1997) - Subduction Zones
1997 NEHRP SITE CATEGORIES A Hard Rock (> 1500 m/sec) B Rock (760 - 1500 m/sec) C Very Dense Soil and Soft Rock (360 - 760 m/sec) D Stiff Soils (180 - 360 m/sec) E Soft Soils (< 180 m/sec) F Soils Requiring Site-Specific Evaluations
HOW CAN HAZUS RESULTS BE IMPROVED? Answer: Develop hazard maps at a fine special resolution which incorporate region- and local-specific source, path, and site effects