1 Terrain Amplification of Wind Loads in Northern Guam

Terrain Amplification of Wind Loads in Northern Guam

2010 NAVFAC Pacific/HawaiiDesigner & Builder Symposium

Wednesday, 1 December, 2010Hilton Hawaiian Village-Coral Ballroom

2 Terrain Amplification of Wind Loads in Northern Guam

Structural Criteria Update•UFC 1-200-01 General Building Requirements

–16 Aug ‘10–Adopts IBC 2009 and ASCE 7-05

•UFC 3-301-01 Structural Engineering–27 Jan ‘10, with Change 1 – 20 Jul ’10–Based on IBC 2006 and ASCE 7-05

•UFC 3-310-04 Seismic Design for Buildings–22 Jun ‘07, with Change 1 – 27 Jan ’10–Based on IBC 2003 and ASCE 7-02

3 Terrain Amplification of Wind Loads in Northern Guam

Wind Design Criteria•170 mph Basic Wind Speed

•Exposure C (per IBC 2009, ASCE 7-05)

•Occupancy Categories & Importance Factors per UFC 3-301-01 Structural Engineering

So What’s Unique about Northern Guam?

TERRAIN AMPLIFICATIONof WIND LOADS

4 Terrain Amplification of Wind Loads in Northern Guam

Terrain Can Affect Wind Speed

5 Terrain Amplification of Wind Loads in Northern Guam

Crest of Cliff-line 300 ft high (west)to almost 600 ft high (east)

Finegayan

North Ramp

Andersen South

½ mile to 1 mile zoneWind loads up-to-doublebaseline Guam conditions

Northern Guam Wind Terrain Amplification

6 Terrain Amplification of Wind Loads in Northern Guam

FinegayanTerrain Effects

12/14/2010

Crest of cliff-line

Shoreline

Route 3

7 Terrain Amplification of Wind Loads in Northern Guam

Finegayan Cliff-line

12/14/2010

8 Terrain Amplification of Wind Loads in Northern Guam

Terrain-amplified Wind Impacts

•Relatively small impact to Building “Shell.”

–Reinforced Concrete Systems usually governed by seismic.

–Some impact to precast/prestressed roof systems.

–Some impact to exterior walls that span high floor-to-floor heights.

•Potential Impact to Components and Cladding (i.e. window, roofing materials, etc.)

9 Terrain Amplification of Wind Loads in Northern Guam

Components & Cladding Wind Loads

Wind Pressures (psf) for various building surfaces

10 Terrain Amplification of Wind Loads in Northern Guam

Way Ahead• Are products commercially available

that meet terrain amplified wind loads requirements?

• What are the BEST commercially available products?

• Are customized products cost effective?

• What are the risks?