2005 AWPA Annual Meeting New Orleans, LA May Nelson G. Bingel III. Chair - ANSI O5 Principal - NESC

Transcription

1 2005 AWPA Annual Meeting New Orleans, LA May ANSI - NESC Update Nelson G. Bingel III Chair - ANSI O5 Principal - NESC

2 ANSI O5 - Material NESC - Safety

3 WOOD QUALITY CLASS LOADS FIBER STRESS POLE DIMENSIONS

4 ANSI O5.1 2 ft L c Bending Load = L c x D (ft-lb) D 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 = k x fiber strength x C 3 (ft-lb) Tension (psi) Compression (psi) Fiber Strength Fiber Stress Modulus of Rupture

5 ANSI O5.1 L c Bending Capacity = k x fiber strength x C3 C 3 (ft-lb)

6 2002 ANSI O5.1 Issued in March 2002 Changes in Scope Changes to Table 1, Fiber Stress Annex A moved into the Standard

7 Scope Simple Cantilever Single Pole Transverse

8 Scope Taller Poles Height of Applied Loads Taper Maximum Stress Point May Occur Above Ground Fiber Stress Height Effect

9 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

10 Symmetrical Bell Curve Distribution #40 COV 6400 psi 8000 psi 9600 psi

11 Scope, Section 9, Table 1 Taller Poles Height of Applied Loads Mean Fiber Stress, COV, Conditioned Taper Maximum Stress Point May Occur Above Ground Fiber Stress Height Effect

12 Net Result of Changes Distribution Little Change Transmission Maybe Larger Poles Conservative

13 Pole Dimension Data Collection ANSI Task Force Todd Brown Martin Rollins Nelson Bingel Stephen Smith Bob Reisdorff

14 ANSI Dimension Data Collection CA OR WA NV ID UT MT WY CO ND SD NE KS MN IA MO WI IL MI IN KY OH WV PA VA NY MD DC NJ DE VT NH CT MA RI ME AZ NM OK AR TN MS AL GA SC NC TX LA FL Sample Locations Coastal Douglas Fir (8) Coastal DF & Western Red (3) Northern Red Pine (3) Southern Yellow Pine (16) Western Red Cedar (5)

15 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

16 ANSI Dimension Data Collection Oversize at Guy Attachments > Class Oversize + Fiber Stress Height Reduction

17 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

18 Change Proposals cont d Section 9 Fiber stress height effect Modify to apply only to poles 60 feet and taller Section Add to the end of the first sentence: o after bark removal and /or shaving

19 Photo Manual

20

21

22

23 Tropical Hardwood Poles

24

25

26 Amazon Region in Brazil

27 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

28 Tropical Hardwood Crossarms

29

30 OSU Through-Boring Project

31 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

32

33

34

35

36 OSU Through-Boring Project Results / Additional Standard Activity Industry Standard Drilling Pattern Understanding of Strength Impact Coordinate with ANSI O5 ANSI O5 to coordinate with AWPA Review treatment effectiveness

37

38 CP 2737 Major Revision Conditionally Accepted Pending Results of Task Force Some Concepts New Ice & Wind Map ASCE 7 Apply Extreme Wind to all Structures Include.87 Grade C Strength Factor Grade B / C 1.5

39 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

40 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 O 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 A or 261-1B.

41 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.

42 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

43 Introduce FRP Structures Accepted Several Rules affected Same Strength & Load Factors as Metal 5% LEL Strength Established by Manufacturers

44 Table 261-1A Strength Factors for Structures, Crossarms, Support Hardware, Guys, Foundations, and Anchors for Use with Overload Factors of Table Strength factors for use with loads of Rule 250B Grade B Grade C Metal and Prestressed-Concrete Structures Wood and Reinforced-Concrete Structures 2, Fiber-Reinforced Polymer Structures Support Hardware Guy Wire 5, Guy Anchor and Foundation Strength factors for use with loads of Rule 250C Metal and Prestressed-Concrete Structures Wood and Reinforced-Concrete Structures 3, Fiber-Reinforced Polymer Structures Support Hardware Guy Wire 5, Guy Anchor and Foundation

45 Average Strength of 3 Poles Accepted to Delete this Rule

46 Delete Alternate OL for Wood Accepted Delete Table 253-2

47

48 2005 AWPA Annual Meeting New Orleans, LA May ANSI - NESC Update Nelson G. Bingel III Chair - ANSI O5 Principal - NESC