FEMA’s Mitigation Assessment Team Program – Where Have We Been and Where Have We Still To Go?

2010 ASFPM National Conference

John Ingargiola – FEMAEric Letvin – URS

Presentation Outline

Program Overview – Where Have We Been?

What Has Been the Effect of the MATs?

Common Vulnerabilities / Recommendations

Areas of Future Research / In-Depth Studies

Objectives of the MAT Program Conducts forensic engineering analyses to determine causes of

structural failure and success Provides recommendation that communities, states and

organizations/agencies can take to reduce future damages and protect lives and property in hazard areas

Increase damage resistance through improvements in construction codes and standards, designs, methods, and materials used for both new construction and post-disaster repair and recovery

Where Have We Been? Nine events since Hugo (Andrew, Iniki, Opal, Fran, Georges

(Gulf Coast and Puerto Rico), Charley, Ivan, Katrina, and Ike Size of the deployments and reports have grown – we have

also branched out to manyorganizations, agencies,and universities.

Benefits of the MAT Studies MAT observations and recommendations have served as

valuable contributions to several other guidance documents, including (FEMA 55, 543, 550)

Codes and Standards – Florida Building Code (Glazing, Asphalt Shingles, Tile Roofing)– ASCE 7 Wind Standard– Coastal A Hazard, ASCE-24 (Updated ASCE 24-05 Flood Design

Standard, ASCE 24-05 adopted by ICC)– Windborne Debris – Florida legislature removed panhandle exemption– Louisiana enacted statewide building code, Mississippi coastal counties

enforce IBC/IRC, Florida Building Commission work group developing comprehensive flood provisions for the Florida Building and Residential Codes

Site Specific Damage FactorsBesides storm characteristics, damage appears to be a function of the following;

– Age of construction and building code used– Quality of construction and building code compliance – Architectural features (e.g., gable versus hip roof)– Quality and age of the flood maps—this determines building

elevation and extent of flood zones– Local site conditions, such as soils types, erosion rates, severity of

waves, topographic effects (wind), amount and size of flood and windborne debris, and local drainage effects

– Building component degradation due to corrosion or termites

Site-Specific Damage Factors

Local site requirements, such as:– Building setbacks– Land use– Height restrictions

House at Poipu Beach after Iniki with transported lava rock. Lava rocks were a local site condition that served as debris, causing additional damage to many structures.

Common Vulnerabilities / Recommendations

75% / 25% rule for flooding Every MAT has surprising / significant

recommendations Many common vulnerabilities / recommendations

from NC to TX and HI

FoundationThe embedment depths specified for pile foundations should be sufficient to ensure the foundation will withstand anticipated erosion and storm forces.

Building Elevation & FreeboardWhen waves reach above the floor system of most elevated buildings, those buildings will be heavily damaged or destroyed. Exceeding the minimum lowest floor elevation requirements of the NFIP can reduce residual flood risk.

BFE = 16 ft NGVD, Floor

at 21.5 ft

Floor at +/- BFE

Concrete Slabs Below BuildingsWhen a slab-on-grade is constructed below an elevated building in a coastal area subject to wave action, it should be designed and constructed in such a way that it will not damage the building foundation when acted on by flood forces.

SitingSiting of buildings close to eroding shorelines puts those buildings at risk and often results in loss of those buildings to erosion and flood effects.

Daulphin Island, AL after Hurricane Georges

Building CodesBuildings should be designed and constructed to at least the minimum requirements in the IBC/IRC or State and local codes if those codes are more stringent.

Buildings constructed to modern building codes demonstrate significantly improved building performance.

Adjuntas, PR after Hurricane Georges

InspectionThe MATs have consistently found numerous significant performance problems that are directly related to construction workmanship deficiencies.

There is a need for increased inspections by designers or third-party inspectors.

Inadequate sheathing attachment – Hurricane Katrina

Areas of Future Research / In-Depth Studies

Although there are many worthy areas of research in the field of building science and natural hazards, the MAT has noted a few specific areas where researchers can provide a greater understanding to architects, engineers, building code officials, as well as local officials and home/business owners.

ScourUnderstanding the local effects of erosion and scour will greatly enhance the siting and design of future structures in coastal areas.

Foundation scour was reported to be 10 feet deep at this house on the Bolivar Peninsula, TX, after Hurricane Ike.

Floodborne DebrisA better understanding of floodborne debris and its effects would help design better foundation systems in the future

Damaged Pilings

Debris fromadjacent house

Other Areas of Potential Research Coastal Flood Velocities Windborne Debris Climate Change Water Infiltration

Area of Unacceptable Performance: Critical FacilitiesAll MATs have noted that, in general, buildings functioning as critical and essential facilities have not performed better than commercial buildings.

The Future?As future hurricanes will undoubtedly impact the MS to TX coast, there will be an opportunity to study the effect of these events on the built environment and the success of the buildings built in the aftermath of the 2005 – 2008 hurricanes.