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2005 AWPA Annual Meeting New Orleans, LA May 15 - 18. ANSI - NESC Update. Nelson G. Bingel III Chair - ANSI O5 Principal - NESC. NESC - Safety. ANSI O5 - Material. WOOD QUALITY. CLASS LOADS. FIBER STRESS. POLE DIMENSIONS. ANSI O5.1. 2 ft. D. Compression (psi).
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2005 AWPA Annual Meeting New Orleans, LA May 15 - 18 ANSI - NESC Update Nelson G. Bingel III Chair - ANSI O5 Principal - NESC
NESC - Safety ANSI O5 - Material
WOOD QUALITY CLASS LOADS FIBER STRESS POLE DIMENSIONS
ANSI O5.1 2 ft D Compression (psi) Fiber Strength Fiber Stress Modulus of Rupture Tension (psi) Lc Bending Load = Lc x D (ft-lb) Class 1 4,500 lb Class 2 3,700 lb Class 3 3,000 lb Class 4 2,400 lb Class 5 1,900 lb Bending Capacity = kx fiber strength x C3 (ft-lb)
ANSI O5.1 Lc Bending Capacity = kx fiber strength x C3 (ft-lb) kxfiber strengthx C3 (ft-lb) kxfiber strengthxC3 (ft-lb)
2002 ANSI O5.1 Issued in March 2002 Changes in Scope Changes to Table 1, Fiber Stress Annex A moved into the Standard
Scope Simple Cantilever Single Pole Transverse
Scope Taller Poles Height of Applied Loads Maximum Stress Point May Occur Above Ground Fiber Stress Height Effect Taper
Table 1 – Fiber Stresses • Eliminate Species not Used • New Footnote 1 • The effects of conditioning on fiber stress have been accounted for in Table 1 values • New Footnote 2 • These designated fiber stresses represent a mean, groundline, fiber stress value with a COV = .20
COV 6400 psi9600 psi Symmetrical Bell Curve Distribution #40 8000 psi
Scope, Section 9, Table 1 Height of Applied Loads Maximum Stress Point May Occur Above Ground Taller Poles Taper Mean Fiber Stress, COV, Conditioned Fiber Stress Height Effect
Net Result of Changes Distribution – Little Change Transmission – Maybe Larger Poles Conservative
Pole Dimension Data Collection • ANSI Task Force - 2004 • Todd Brown • Martin Rollins • Nelson Bingel • Stephen Smith • Bob Reisdorff • Martin Rollins • Todd Brown
ANSI Dimension Data Collection • Coastal Douglas fir 6,185 poles • 9 Producers; 11 Locations • Southern Yellow Pine 5,429 poles • 11 Producers; 16 Locations • Western Red Cedar 5,701 poles • 5 Producers; 9 Locations • Northern Red Pine 2,122 poles • 2 Producers; 3 Locations Grand Total 19,527 poles
ANSI Dimension Data Collection Oversize at Guy Attachments Class Oversize + Fiber Stress Height Reduction >
Change Proposals • 1 Scope and general requirements • Remove design considerations from 1.1 Scope • Create 1.3 Design Considerations • Explain maximum stress point more clearly • State that fiber stress height reduction need not apply to poles 55 feet and shorter • State that fiber stress height reduction need not apply to braced H-frames due to load sharing
Change Proposals cont’d • Section 9 Fiber stress height effect • Modify to apply only to poles 60 feet and taller • Section 6.2.1 • Add to the end of the first sentence: • “after bark removal and /or shaving”
Tropical Hardwood Poles • Task Force to Review Test Data • David D’Hooge • Bob Kluge • Art Peralta • Gina Cerda • Martin Rollins • Jeff Morrell • Nelson Bingel to coordinate the effort
OSU Through-Boring Project • Computer Finite Element Analysis • Compare impact on pole strength • Hole size • Hole spacing • Hole distance from pole edge • Test Procedure • Build Test Stand • Obtain Poles • Pole Testing
OSU Through-Boring Project • Industry Standard Drilling Pattern • Understanding of Strength Impact • Coordinate with ANSI O5 • ANSI O5 to coordinate with AWPA • Review treatment effectiveness Results / Additional Standard Activity
CP 2737 – Major Revision • Conditionally Accepted • Pending Results of Task Force 5.2.1 • Some Concepts • New Ice & Wind Map – ASCE 7 • Apply Extreme Wind to all Structures • Include .87 Grade C Strength Factor • Grade B / C differential @ 1.5
60 ft Exclusion Limit • Eliminate exclusion but calibrate to previous practice. • Only partially accomplished • Increase in Medium Loading District • Requires utilities to consider additional load case
Incorporate 2002 ANSI O5.1 • Rule 261 A2b(1) • Include reference to “fiber stress height effect” • b. Permitted Stress Level • (1)Natural Wood Pole • The permitted stress level of natural grown wood poles of various species meeting the requirements of ANSI O5.1-2002 shall be determined by multiplying the designated fiber stress (recognizing the “fiber stress height effect” as appropriate)set forth in that standard by the appropriate strength factors in Table 2610-1A or 261-1B.
Incorporate 2002 ANSI O5.1 • Rule 261 A2b(1) • Include reference to fiber stress height effect • Rule 261 A2a exception 1 • Delete because of reference to allowable groundline stress EXCEPTION 1: When installed, naturally grown wood poles acting as single-based structures or unbraced multiple-pole structures, shall meet the requirements of Rule 261A2a without exceeding the permitted stress level at the ground line for unguyed poles or at the points of attachment for guyed poles.
Introduce ASCE RBD Manual • Three variations submitted • Refer to the manual • 2 new rules including the manuals • Major rewrite incorporating the manual • All Rejected • Manual only addresses single, un-guyed • Not a consensus document • Several “To Be Determined” values
Introduce FRP Structures • Accepted • Several Rules affected • Same Strength & Load Factors as Metal • 5% LEL Strength Established by Manufacturers
Table 261-1A StrengthFactors for Structures, Crossarms, Support Hardware, Guys, Foundations, and Anchors for Use with Overload Factors of Table 253-1
Average Strength of 3 Poles • Accepted to Delete this Rule
Delete Alternate OL for Wood • Accepted – Delete Table 253-2
2005 AWPA Annual Meeting New Orleans, LA May 15 - 18 ANSI - NESC Update Nelson G. Bingel III Chair - ANSI O5 Principal - NESC