ASTM D1036-1999(2005) Standard Test Methods of Static Tests of Wood Poles《木电杆的标准静态试验方法》.pdf

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1、Designation: D 1036 99 (Reapproved 2005)Standard Test Methods ofStatic Tests of Wood Poles1This standard is issued under the fixed designation D 1036; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num

2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONOne of the important factors involved in the design and economical use of poles for the support ofaerial communication and power lines is

3、 the value of the maximum fiber stress for the different speciesof timber used for poles. In order to gain information on this characteristic, mechanical tests on polesize specimens have been made by numerous investigators. These tests have been made in variousmanners, such as the use of a testing m

4、achine, holding the pole butt horizontally in a crib and applyingthe load at the tip, setting poles in the earth and applying the load at the tip, and so forth. The amountof seasoning the test poles have received and the type of preservative treatment applied to the polesare additional variables. Th

5、e result is that it is difficult, if not impossible, to obtain sufficientinformation pertaining to the various tests to permit accurate comparisons.It is the purpose of these test methods to cover testing procedures in sufficient detail so that theresults of tests made in accordance with the test me

6、thods defined will be comparable. It is, of course,not intended that using other test methods that may be better adapted to a particular investigationshould be discouraged. However, experience gained from tests of several hundred poles has indicatedthe test methods specified are entirely practicable

7、.The data forms presented have been found to be convenient for recording the test data and formaking the calculations necessary for the proper analysis of the test results.1. Scope1.1 These test methods cover determination of the bendingstrength and stiffness of wood poles. Knowledge of thesepropert

8、ies is used in providing for reliable and economicaldesign with poles of different species, size, or grade.1.2 Two test methods are included: the cantilever testmethod and the machine test method.1.3 Provision is also made for extracting small clear speci-mens from the butt section and determining s

9、tatic bending andcompression parallel to grain strength values in accordancewith Test Methods D 143.1.4 The procedures specified in these test methods apply totests of either treated or untreated material.1.5 The values stated in inch-pound units are to be regardedas standard. The values given in pa

10、rentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-pr

11、iate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 143 Test Methods for Small Clear Specimens of TimberD 198 Test Methods of Static Tests of Lumber in StructuralSizes2.2 ANSI Standard:3O5.1 Specificati

12、ons and Dimensions for Wood Poles1These test methods are under the jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.04 on Pole and PileProducts.Current edition approved April 1, 2005. Published April 2005. Originallyapproved in 1949. Last previous editi

13、on approved in 1999 as D 1036 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Nat

14、ional Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Summary of Test Method3.1 Major Tests:3.1.1 In the cantilever test method, the pole is supportedsecurel

15、y from butt to ground line in a horizontal position, anda load is applied near the pole tip by means of a pulling line.3.1.2 In the machine test method, the pole is supported nearthe butt and tip, and a load is applied at the ground line by themoving head of a mechanical testing machine.3.1.3 Determ

16、inations of age, rate of growth, moisture, anddensity are also made.3.2 Minor Tests:3.2.1 Small clear specimens are taken from the butt sectionof the tested poles for the determination of strength values suchas static bending, compression parallel to grain, toughness,compression perpendicular to gra

17、in, and hardness. The overallobjectives of the program will determine which of these testsare desired.4. Significance and Use4.1 Tests of wood poles are made to determine:4.1.1 Data for use in establishing allowable stresses,4.1.2 Data upon which to base economical pole line design,4.1.3 Data on the

18、 strength properties of different species inpole sizes,4.1.4 Data as to the influence of defects on the strengthproperties of poles,4.1.5 Data as to the effect of preservatives and preservativetreatments on the strength properties of poles, and4.1.6 Data for correlating the strength properties of fu

19、ll-sizepoles with those of small clear specimens of the same species.4.2 Treating procedures to which poles have been subjectedmay introduce variables that prohibit direct comparisons be-tween different groups of data. Complete information on thetreating techniques shall form a part of the test reco

20、rds.COLLECTION OF MATERIAL5. Identification5.1 The material for test shall be selected by one qualified toidentify the species.6. Number of Major Specimens6.1 For each species under investigation it is desirable thata minimum of 50 specimens be selected for test. The polesshall be carefully chosen a

21、s representative of the commercialproduct being supplied.NOTE 1Tests may be conducted to study the effect of some particularcharacteristic and in such cases the selection of test specimens shall bemade in such a manner as to ensure that the range of the characteristicunder study has been adequately

22、sampled.7. Field Notes7.1 Field notes fully describing the material shall be care-fully made by the collector. These notes shall, so far aspossible, supply data outlined as follows and shall be incorpo-rated into the test records:FIELD NOTESProject No.Locality cutCountySlope . ElevationUndergrowthCr

23、ownSoilShipment No.SpeciesDate cutSeedling or sproutHow and when transported from woodsAge of tree in yearsTreatmentSeasoningPreservative retentionAge in service (if pole had been in service)Age of pole since treatmentSource of pole (supplier, region, and climate), if pole had been in serviceClassif

24、ication standardCondition of pole (decay, woodpecker holes, splits), if pole had beenin service8. Field Marking8.1 Each specimen shall be legibly marked on the butt withits length, class, and source of supply, in accordance with therequirements of ANSI O5.1, using such symbols as may applyto each sp

25、ecimen.CONDITIONING AND MEASURING OF SPECIMENSFOR TESTING9. Conditioning9.1 Two basic procedures for conditioning and moisturecontent are provided as follows:9.1.1 Test Method A, providing for air seasoning and buttsoaking of poles prior to test.9.1.2 Test Method B, providing for tests of poles in t

26、hefull-length green condition.NOTE 2Test Method A, providing for butt soaking of poles afterseasoning, has been used as a preconditioning test method when it isdesired to provide tests simulating, as nearly as possible, actual field useunder certain climatic conditions.Test Method B, providing for t

27、ests of poles in the green condition, hasbeen used where the stability of moisture-strength relationships thusestablished is particularly desired for comparison between species, grades,and testing procedures, and for establishing relationship of strengthbetween full-size poles and that of small clea

28、r specimens taken from thepole material.10. Alternative Conditioning Requirements10.1 Test Method AAll poles tested shall be air-seasonedon skids at least 2 ft (600 mm) above the ground. Prior totesting, the butt sections (from the groundline to the butt) shallbe soaked in water in order to bring th

29、e moisture content of thissection equal to or above the fiber saturation point. Buttsoaking shall be conducted in a manner to prevent decay andwith the poles in a vertical position. Moisture determinations ofthe butt section shall be made by means of increment borings.The determinations shall be mad

30、e by using the portions of theborings nearest the pole surface with a length of boring equalto one-half the pole radius.NOTE 3For the purposes of these test methods, poles will beconsidered air-seasoned when two successive determinations made oneD 1036 99 (2005)2week apart indicate the moisture cont

31、ent of the pole to have reached apractically constant value at or below 22 %.10.2 Test Method BAll poles to be tested shall be selectedin the green condition and shall be tested before any seasoninghas taken place. If there is any delay in testing that would resultin seasoning, this shall be prevent

32、ed by proper storage,preferably by full-length immersion in water. If other methodsof maintaining the green condition are employed, care shall beexercised to prevent the development of stain or decay. Specialmoisture determinations of the test sections are not requiredprior to test (Section 25).11.

33、Initial Measurements11.1 Before placing a pole in the testing apparatus, a recordshall be made of the following items:11.1.1 Weight,11.1.2 Length to the nearest 1 in. (25 mm),11.1.3 Class,11.1.4 Circumference at butt, at tip, and at the ground line tothe nearest116 in. (1.5 mm),11.1.5 Diameter of ea

34、ch knot over12 in. (13 mm) indiameter and its location on the surface of the pole relative tothe butt and to the longitudinal center line of the face of thepole, and11.1.6 Any possible strength reducing defects observedother than knots, such as sweep, crook, checks, shakes, spiralgrain, insect damag

35、e, and the like.STATIC BENDING TESTS OF POLESCantilever Test Method12. Apparatus12.1 A schematic drawing of the testing apparatus and fieldlayout for conducting the tests is shown in Fig. 1. Forconvenience of reference, the principal features of the layoutare denoted on the drawing by capital letter

36、s. The pole to betested shall be held securely from the butt to the ground line inthe crib A. The crib shall be built in such a manner that therewill be no significant movement of the pole butt during the test.The design of the crib and holding devices shall be such that allvertical and rotational m

37、otion of the pole shall be prevented.12.2 A support B shall be provided at a point about threequarters of the distance from the ground line to the point ofload application to minimize vertical movement at that pointand reduce the stress from the weight of the pole. This supportshall be such that any

38、 friction associated with the deflection ofthe pole under load shall not be a significant portion of themeasured load on the pole.12.3 As a pole is placed in the testing apparatus, it shall berotated to align the pole so as to minimize out-of-plane shearstresses due to torque. The pole shall be shif

39、ted longitudinallyuntil its ground line coincides with the front face of the crib,and then it shall be secured firmly in place (see 12.1). Awooden saddle C, Fig. 1, with a concave surface on the poleside and rounded edges, shall be placed against the pole toprevent injury to the ground-line section.

40、 This saddle shall beFIG. 1 Schematic Layout of Field Mechanical Tests of Wooden PolesD 1036 99 (2005)3made of wood at least as soft as the pole under test and shallhave dimensions as shown in Fig. 2.13. Load13.1 The load shall be applied at a point 2 ft (600 mm) fromthe tip of the pole by a power w

41、inch, or other means ofsufficient capacity and capable of pulling at a constant rate ofspeed. The pulling line shall be kept level between the winchposition and the point where load is applied to the pole. Theload shall be applied continuously until the pole fails, and atsuch a rate of speed as to c

42、ause a deflection at the point of loadof N in./min (mm/min), as determined by the equation:N 5 2pZL2/3Ct(1)where:N = rate of deflection, in./min (mm/min),Z = rate of fiber strain, in./in.min (mm/mmmin) = 0.0010, the value specified in Test Meth-ods D 198,L = lever arm, in. (mm), andCt= circumference

43、 at point of load application, in. (mm).14. Pulling Line14.1 The pulling line shall be secured around the pole at theload point. The load measuring device shall be placed in serieswith the pulling line and the line to the winch with afree-running swivel on each side of it.15. Winch Positions15.1 If

44、the winch G, Fig. 1, is set far enough away from thepole to make the angle between the initial and final positions ofthe pulling line small, the error in assuming that the pull isalways perpendicular to the original direction of the pole axiswill be negligible. The winch shall be located at the posi

45、tionsgiven in Table 1.16. Load Measurement16.1 Load shall be measured by a suitable measuring deviceplaced in series in the pulling line. The recommended methodis a calibrated metal tension bar fitted with calibrated electric-type strain gages, suitably wrapped or housed for protectionagainst shock

46、when the pole breaks. This method permitsremote reading of loads and minimizes the possibility ofpersonal injury during test. Alternatively, where electric-typestrain gaging equipment is not available, load may be measuredby a dynamometer of suitable capacity, graduated in 50-lb(200-N) divisions. Ca

47、libration of the dynamometer shall bechecked at frequent intervals during the tests. The load-measuring device shall be supported on a sled or cradle movingon a suitable platform or level space. The sled or cradle and thesurface on which it moves shall be such that the force requiredto pull it shall

48、 not add materially to the measured load on thepole.17. Deflections17.1 The deflection of the pole at the point of load shall bemeasured at such intervals of load as to provide not less than15 simultaneous readings of load and deflection. A greaternumber of readings (25 to 40) is preferred. The meas

49、urement ofthe deflection of the load point shall be made in a directionperpendicular to the unloaded position of the pole axis. Ameasurement of the movement of the load point toward the buttresulting from the deflection shall also be made at eachincrement of load.NOTE 4These measurements may be facilitated if a piece of plywood(datum board), E, Fig. 1, is ruled with lines perpendicular to the unloadedaxis of the pole and spaced 1 in. (25 mm) apart. The edge of the plywoodboard away from the pole may be used as the datum line from which thedeflection is measured. Then as t