linda noson agra earth & environmental (425) 820-4669 nonstructural protection guide for schools...
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Linda Noson AGRA Earth & Environmental (425) 820-4669
Nonstructural Protection Guide for Schools
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Nonstructural Protection Guide: Purpose
Improve the safety of the school community
Provide a tool for District Staff and School Site Teams for developing, implementing, and maintaining a school nonstructural protection program
Learning Objectives
Recognize the potential for earthquake-induced damage to WA schools
Identify nonstructural building elements
Visualize the potential impacts of damaged nonstructural elements
Evaluate and select nonstructural protective measures
Take action RIVET
Why protect nonstructural elements from earthquakes?
Casualties and building closures may result from nonstructural damage even when structural damage is absent or slight
Low levels of earthquake shaking can severely damage nonstructural elements
Costs to repair nonstructural damage may equal building replacement costs
Nonstructural Protection Guide
Section A Background
Information
Section B Inventory Process
Section C Protective Measures
Section A Background Information
Earthquake Threat
Nonstructural Elements
Definition
Earthquake Damage
Nonstructural Protection Program
Earthquakes damaged Washington schools in the past and will in the future
90% of all earthquakes occur at the boundaries of slowing moving slabsof rock, called plates
Three plates interact in the Pacific Northwest and B.C.
Graphic: Garry Rogers, PGC, Canada
Earthquake Source Zones
1
23
North America PlateNorth America Plate
PacificPacific PlatePlateJuan de Juan de Fuca Fuca PlatePlate
Maximum size earthquake for each Zone:
Zone 1 - Deep Magnitude 7.5
Zone 2 - Shallow Magnitude 7+
Zone 3 CascadiaSubduction ZoneMagnitude 8 - 9
(Graphic: Garry Rogers, Pacific Geoscience Centre, Canada)
Notable Washington EarthquakesZone (1) - Deep, Puget Sound
1949 Olympia • M=7.1 MMI = VIII
• Total State loss $100-165 million
• WA School loss $60 million
• 30 closed temporarily
• 10 permanently
Seattle Schools• $28 million loss
• 21 schools damaged
• 5 closed temporarily
• 3 permanently
1965 Seattle-Tacoma• M=6.5 MMI = VII
• Total State loss $60 million
Seattle schools• 8 closed temporarily
• 2 damaged severely
All losses in 1998 dollars MMI = Modified Mercalli Intensity
Scale (I-XII) M = Magnitude
Zone 1 - Deep Earthquakes
Maximum magnitude = 7.5 (1949: M = 7.1)
Castle Rock High School 1949Lafayette School, Seattle 1949
Zone 2 - Shallow EarthquakesMaximum magnitude ~ 7
OlympiaOlympia
Seattle Fault
UpUp
UpUpUpUp
UpUp
DownDown
TacomaTacoma
UpDow
n
Seattle Fault - recent small earthquakes
Zone 3 - Cascadia Subduction Zone Maximum magnitude = 9
Tsunamis SandsTsunamis Sands
Old marsh
Last subduction zone earthquake January 26, 1700
Top of new march
Nonstructural Elements
Definition of nonstructural elements
Causes of nonstructural damage
Benefits of nonstructural protection
Limitations of nonstructural guide
Risk Control Program
NonstructuralElementsSupports building useand enhances appearance:
•Architectural•Mechanical•Electrical•Furniture & Equip.•Hazardous Materials
StructuralElementsPrevents building collapse under gravity, wind, earthquake, and other forces
Graphic: Federal Emergency Management Agency
Causes of nonstructural damageImposed Deformation
Distortion of window frameshattering windows
Distortion of suspended ceilingcausing recessed lights to fall
Photos: Earthquake Engineering Research Institute
Causes of nonstructural damageImposed Deformation
Door jammed shut bydistortion of wall. Victimaccessed through wall.
Photo: Earthquake Engineering Research Institute
Causes of nonstructural damageOverturning
Photos: Earthquake Engineering Research Institute
Causes of nonstructural damageSliding and Falling
Science Equipment
Mixing of hazardouschemicals
Photos: Earthquake Engineering Research Institute
Causes of nonstructural damage Swaying and falling
Photos: Earthquake Engineering Research Institute
Causes of nonstructural damage Pounding
Collision between two buildings or two building wings
Damage to structural and nonstructural elements intensified where buildings or building sections join
Nonstructural damage• piping• wiring• wall finishes
Nonstructural Program Benefits
Earthquake safety• reduces casualties• improves exit safety• accelerates recovery
Safety & Security• reduces theft• promotes team work• improves normal
operational safety
Guide Limitations
Protective measures cannot guarantee safe performance
Specialized expertise will be required for some elements
Available resources inadequate to eliminate all hazards
Failure of Reinforced and Braced Masonry Chimneys
Photos: Earthquake Engineering Research Institute
Risk Control Program
Preparedness• A capability to
respond and recover to emergencies
• Planning• Training• Emergency supplies
• Actions initiated by emergency
• Drop, cover and hold
Prevention and Mitigation• Reduce damage and
injuries by making the physical environment more hazard resistant
• Actions completed prior to earthquake emergency
• Nonstructural retrofit