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Earthquake Risk and the Workplace
David Bonowitz, S.E.Chair, SEAONC Existing Buildings Committee
Commission on Health and Safety and Workers’ CompensationCatastrophe Preparedness Conference
April 7, 2006
Issues How can we enhance worker safety?What have past earthquakes taught us?What do engineers know that we don’t?
Earthquake losses Your perspective vs. the building code’s Four open secrets
EQ losses: What’s at risk? Life safety Building and contents Business continuity Public services Tax base Community resilience Neighborhood character & history Good will
1. No code for existing buildings Upgrades sometimes triggered
Change of occupancy Major renovation
Otherwise up to owner, tenants Exceptions
Hospitals (SB 1953) Unreinforced masonry (SB 547)
Vulnerable structure types Unreinforced masonry Tilt-ups Unbraced cripple walls Hillside houses Soft story apartments (and HOGs) Non-ductile concrete frames Parking structures (precast concrete)
Unreinforced masonry1994
20031989
6800 in 1990 60% mitigated Remaining risk
Life safety Housing Building value Small business Neighborhood
character, history
URM in the Bay Area
Tilt-ups Evolving code
since 1971 Significant
damage in 1994 Thousands in
Bay Area No mandatory
retrofit
Tilt-ups Remaining risk
Building value Contents value Business
continuity 1994
Non-ductile concrete frames Pre-1976
inventory not quantified
All occupancies Hard to spot
from street Complex and
expensive to retrofit 1971
Non-ductile concrete frames: 1994
Non-ductile concrete frames Remaining risk
Life safety Building value Business
continuity Emergency
response Tax base Good will
2. Nonstructural hazards count Often overlooked in construction Sometimes life-threatening
Falling hazards Egress Hazardous materials Fire
Often more costly and disruptive
Nonstructural hazards Precast panels Ceilings Shelves/equip Hazmat
1964
Nonstructural hazards Precast panels Ceilings Shelves/equip Hazmat
2005
Nonstructural hazards Precast panels Ceilings Shelves/equip Hazmat
2001
Nonstructural hazards Precast panels Ceilings Shelves/equip Hazmat
Nonstructural hazards Precast panels Ceilings Shelves/equip Hazmat
2001
Nonstructural hazards Precast panels Ceilings Shelves/equip Hazmat
1994
EQ losses: What’s at risk? Life safety Building and contents Business continuity Public services Tax base Community resilience Neighborhood character & history Good will
Business disruption Nonstructural damage Infrastructure & servicesWorkforce stability
Nonstructural damage
Infrastructure & services
1994
1989
Parking structures: 1994 Inventory unknown Remaining risk
Life safety Building value Business continuity
Soft story apartments “Tuck-under” Most residential 1960s-70s
Older in S.F.
Bay Area soft story risk 15,000 buildings (1 in 6 multistory MFR)
500,000 people
San Francisco: 5700 buildings (over half) 180,000 people Half of S.F.’s total economic loss in 7.2 eq
Santa Clara County: 2630 buildings (1 in 3) 90,000 people
Soft story apartments
1994
1989
19712003
1994
1989
1971
2003
Soft story apartments Remaining risk
Life safety Housing Building value Personal
property Small business Emergency
response
Soft story apartments No mandatory
retrofit in Bay Area AB 304 Berkeley CAPSS
3. Codes are about Life Safety Not damage prevention Not business continuity Not workforce stability Not post-earthquake recovery
Preparedness in perspective
1989 1994 2006 2012?
Response Recovery Mitigation
4. Best preparation is mitigation Awareness, education Self-assess risks Professional consultation (engineer, lender,
insurer, attorney?)
Resources Seismic Safety Commission:
seismic.ca.gov Commercial Property Owner’s Guide (1998) Risk Management Tools
ABAG: quake.abag.ca.gov Preparing your business Liability of businesses
Lessons1. There is no code for existing buildings2. Nonstructural hazards are significant3. Building codes are about Life Safety4. Mitigation is the best Preparation
Recommended