Valmont Industries, Inc. · NYSE:VMI
Valmont Industries — Technical Presentation (2016)
15 slides from Valmont Industries's technical presentation, 2016
Slide 1: Effective Projected Area (EPA)
EFFECTIVE PROJECTED AREA (EPA) © 2016 Valmont Industries, Inc. All rights reserved.
Slide 2: Objectives
Objectives • Know the difference between Wind Load and Dead Load • Understand what EPA is and why it’s important • Learn the factors of EPA • Find fixture EPA on spec sheets • Size Valmont poles with adequate EPA requirements 2 © 2016 Valmont Industries, Inc. All rights reserved.
Slide 3: Effective Projected Area (EPA)
Effective Projected Area (EPA) • Effective Projected Area • Projected Area (PA) multiplied by the drag coefficient (Cd) • Projected Area (PA) of an Object • Length multiplied by Width • Drag Coefficient (Cd) • Shape Factor of the Object 3 © 2016 Valmont Industries, Inc. All rights reserved.
Slide 4: Wind Load and Dead Load
Wind Load and Dead Load Dead Load acts in the vertical plane while Wind Load acts in the horizontal plane. Valmont engineering needs the locations, sizes, and weights of all objects to determine the wind load and dead load applied to the structure. The distance of the load up from the base, and the
Slide 5: Wind Load
Wind Load The wind load, is a direct result of the Effective Projected Area (EPA), and is always used in the design of the pole. sail When thinking about the wind load, imagine that each object on the pole is a sail from a sailboat. The sails grab and resist wind from passing through, creating more
Slide 6: Why EPA is Important
Why EPA is Important Adding a load with an EPA too large for a pole may cause the pole to fail. Enough wind force may cause steel or aluminum poles to buckle or crack and fail at the welds. It’s important to follow all EPA guidelines to correctly size a pole. States or customers may require sizing r
Slide 7: What is Projected Area (PA)?
What is Projected Area (PA)? Projected Area Projected Area is the measure of a three dimensional object on a two dimensional area, known as the projected area. Since PA is measured in square feet, think of the concept as the object’s shadow. Engineers use this to identify the wind resistance and for
Slide 8: Factors of EPA
Drag Projected Factors of EPA Area The Effective Projected Area contains two parts: • Drag Coefficient (Object) • The Projected Area The shape of the object will vary the drag coefficient. The drag coefficient is a calculated multiplier based on the amount of resistance the object has. Any object th
Slide 9: Common Drag Coefficients (Cd)
Drag Projected Common Drag Coefficients (Cd) Area Pole Drag Coefficients Round Pole: 0.45 – 1.10 Square Pole: 1.25 – 1.90 Luminaire Drag Coefficients Rounded Luminaire: 0.5 Flat Luminaire: 1.2 Sign Drag Coefficients: 1.12 – 1.30 Banner Drag Coefficient: 1.45 Traffic Signal Drag Coefficient: 1.20 9 ©
Slide 10: Shape Effects EPA
Shape Effects EPA For example, according to AASHTO, a rectangular flat shape will create around 60% more resistance than a round object. Because of this, the correct loading weight and EPA must be known before sizing or selecting a pole. 10 © 2016 Valmont Industries, Inc. All rights reserved.
Slide 11: EPA Effects Structure Size
EPA Effects Structure Size Low EPA High EPA higher drag coefficient = larger EPA = more resistance = larger structure 11 © 2016 Valmont Industries, Inc. All rights reserved.
Slide 12: Pole Size Requirements - Fixture
Pole Size Requirements - Fixture 1.47 sq. The EPA of a fixture or ft. fixture cluster should be 1.4 sq. ft. provided by the manufacturer on the product spec sheet. Philips Cobra Head If the EPA is not clearly stated, reach out to the manufacturer before sizing the pole. Cluster EPA values: Spaulding
Slide 13: Pole Size Requirements
Pole Size Requirements Engineering will calculate the EPA for your fixture, traffic signals, trussing, Footnotes will banners, or other say where the attachments, and find a load is calculated. pole that can meet your needs. Keep in mind the wind requirements designated by the state or customer (ex:
Slide 14: Pole Size Requirements – Custom Design
Pole Size Requirements – Custom Design If you are unable to find a pole that fits your EPA and loading needs, contact your Valmont RSM or PA. Valmont continually provides designs and quotes for custom applications. 14 © 2016 Valmont Industries, Inc. All rights reserved.
Slide 15: Thank You!
THANK YOU! valmontstructures.com © 2016 Valmont Industries, Inc. All rights reserved.