Building Safe School Programs. Seismic Zones and Codes Change 1976 (10% PE in 50 yrs) 6 Regions on 2008 USGS hazard map 4/6/2012

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1 Building Safe School Programs Yumei Wang, PE, F.ASCE Council on Disaster Risk Management, Chair and Edward C. Wolf Parent Advocate April 10, 2012 Outline Seismic Hazards in Schools around the U.S. CA, WA, UT, and SC New Madrid and Memphis URM vs Wood shake table videos Killers: URM, soft stories, tsunamis Build Safe School Programs around the U.S. Oregon Mitigation Program Example Collapse Prevention, Risk Management, Results Y Wang and EC Wolf Is There a School Safety Problem in US? Yes, Lots Dangerous Schools in US Seismic Regions Schools built to inadequate seismic zoning Schools built to inadequate building codes 1,000s school buildings with high risk of collapse in major earthquakes in US Millions vulnerable students in public schools Seismic Zones and Codes Change (10% PE in 50 yrs) (UBC Map) (Algermissen & Perkins) %g Zone 6 Regions on 2008 USGS hazard map 2 WA 6 OR CA ( safest schools) Long Beach, Calif Magnitude schools collapsed. 120 damaged Laws on seismic school safety. No URMs. But, non-ductile schools exist 1 CA 3 UT 5 NM 4 SC Y.Wang, 9/3/08 1

2 WA, UT, and SC WA: 1949 earthquake, 1955 seismic codes on schools. >3,000 schools. Statewide seismic school mitigation program may be initiated. (John Schelling and Cale Ash) UT: Building URM schools until 1960s. Benchmark year mid 1990s. Perhaps 60% of ~1,087 schools are URMs. Low % mitigated. (Barry Welliver and Bob Carey) SC: Scenario estimates 220 schools with significant damage. Charleston closed 6 schools due to seismic risk New Madrid and Memphis New Madrid: M7.7 scenario. 1,599 schools >= moderate damage 20,000 schools Estimates all structural types 132,000 URMs in study region ( Memphis: 286 URMs schools at-risk. Late awareness? Current codes? (CERI s Howard Hwang and Yang Wei Lin 1997) New Madrid M7.7 Scenario (MAE, 2008) NEHRP Soils and Liquefaction Hazards (MAE 2008) Many Memphis Schools susceptible to Liquefaction & Lateral Spreading damage Examples: Liquefaction & Lateral Spreading Before During Shaking After Sand supports loads through grain-to-grain contacts Fluid pressure rises Grains float apart Sand loses strength & can flow downhill Water, sand ejected Sand is compacted Sand volcanoes on surface 2

3 Memphis: White Station HS (CERI 1997) Shake Table Videos: Non-Ductile URM versus Ductile Wood 9 Buildings: 1953 RC, 1954 URM, 1955 URM, 1956 RC, 1959 RC, 1960 URM, 1960 URM, 1966 RC, 1967 URM Scenario: all moderate or heavy damage Source: National Laboratory for Civil Engineering, Lisbon, Portugal (2005) Source: NEESWood Project, University at Buffalo NY (2006) Build Safe Schools Programs in U.S. Collapse Prevention to eliminate mass casualties minimum performance Building Risk Inventory Risk Management Results-Oriented Increase Student Earthquake Safety Drop Cover Hold Drills Identify Vulnerabilities Reduce Falling Hazards Maintain Clear Exits Strengthen Dangerous Buildings & Ground Conditions Mitigating Oregon Schools: Risk Management Until 1990s, Oregon had Inadequate Seismic Zoning Inadequate Building Codes Source: KPFF CREATED BUILDING INVENTORY WITH SEISMIC SCORES FEMA 154 Rapid Visual Screening (RVS) Pre-engineering evaluation Identifies older buildings Buildings on poor soils Buildings with characteristics that can lead to major damage Guides need for engineering study Five Key Factors determine Seismic Vulnerability 1. Seismicity Zone (USGS Ground Motion) 2. Building Structural Type (15 options) 3. Building Irregularities (Plan & Vertical) 4. Original Construction Date (vs. Codes) 5. Soil Type (A to F; amplify motion to 10x) 3

4 FEMA 154 BUILDINGS BENCHMARK DATES IN OREGON: W1 S NA >3:1979 & <3:1990 S4 Plan Irregularity Wood Frame (<5,000 sq ft) Light Steel Frame Steel Frame with Concrete Shear Walls C1 C2 PC >3: & <3:1990 Concrete Moment Frame Concrete Shear Wall Concrete Tilt-Up L-Shaped T-Shaped U-Shaped L-Shaped T-Shaped U-Shaped RM1 URM Large Opening Large Opening Weak Link Between Larger Building Plan Areas Weak Link Between Larger Building Plan Areas Reinforced Masonry (flexible diaphragm) Unreinforced Masonry Vertical Irregularity BUILDING CODE SOILS Amplification of shaking A B D C E F Setbacks Hillside Highway 880, Oakland CA 1989 Liquefaction Short Short Column Soft Story Soft Story Basic RVS Scores Assume a Rock Foundation; Soils C, D and E amplify ground motion (lowers RVS score) Government Hill School, AK 1964 Numbers of Buildings RESULTS: RVS Scores For K12 Schools W1 W2 S1 S2 S3 S4 S5 C1 C2 C3 PC1 PC2 RM1 RM2 URM Statewide Seismic Ratings ( 2007) 1,101 schools 2,185 buildings 273 Very High 745 High 501 Moderate 666 Low 94 URMs From -1.5 to -1 From -0.9 to -0.5 From to 0 From 0.1 to 0.5 From 0.6 to 1.0 From 1.1 to 1.5 From 1.6 to 2.0 From 2.1 to 2.5 From 2.6 to 3.0 From 3.1 to 3.5 FEMA 154 (RVS) Score Ranges 100% 10% 1% 0.1% 0.01% 0.001% Higher Probability of Collapse From 3.6 to 4.0 From 4.1 to 4.5 From 4.6 to 5.0 Lower From 5.1 to 5.5 From 5.6 to 6.0 From 6.1 to State Seismic Mitigation Program 4

5 Concrete & Masonry: non-ductile Gyms: Pre-cast Concrete Tilt-ups Y.Wang, 9/3/08 Schools Deaf and Blind: Soft-Stories Cannon Beach Elementary in Tsunami zone Elementary school Bridge Destroyed 1964 Tsunami Author Contact Information Yumei Wang Edward C. Wolf 5