Earthquake Risk and the Workplace Bonowitz.pdfEarthquake Risk and the Workplace David Bonowitz, S.E. Chair, SEAONC Existing Buildings Committee. Commission on Health and Safety and

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


2005


2001



2001


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

Documents

Earthquake Risk and the Workplace Bonowitz.pdfEarthquake Risk and the Workplace David Bonowitz, S.E. Chair, SEAONC Existing Buildings Committee. Commission on Health and Safety and