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1、BRITISH STANDARD BS 5649-7: 1985 Lighting columns Part 7: Method for verification of structural design by calculation UDC 624.971:628.971:624.04 Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5649-7:1985 This British Standard, having bee
2、n prepared under the direction of the Road Engineering Standards Committee, was published under the authority of the Board of BSI and comes into effect on 30 August 1985 BSI 01-1999 The following BSI references relate to the work on this standard: Committee reference RDB/28 Draft for comment 77/1015
3、5 DC ISBN 0 580 14461 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Road Engineering Standards Committee (RDB/-) to Technical Committee RDB/28 upon which the following bodies were represented: Aluminium Federation British Precast Con
4、crete Federation Ltd. British Steel Industry Cement and Concrete Association County Surveyors Society Department of Transport Design Council Electricity Supply Industry in England and Wales Institution of Highways and Transportation Institution of Mechanical Engineers Institution of Municipal Engine
5、ers Institution of Public Lighting Engineers Lighting Column Manufacturers Association Lighting Industry Federation Ltd. Amendments issued since publication Amd. No.Date of issue Comments Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 56
6、49-7:1985 BSI 01-1999i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Definitions1 3Symbols1 4Basis of calculations2 5Strength requirements (ultimate limit state)2 6Deflection requirements (serviceability limit state)7 7Permissible modifications to verified column7 Figure
7、 1 Values of factor f18 Figure 2 Closed regular cross sections of metal lighting columns9 Figure 3 Values of factor f510 Figure 4 Unreinforced door openings in metal lighting columns11 Figure 5 Cross sections of reinforced door openings in metal lighting columns12 Figure 6 Elevation of reinforced do
8、or openings in metal lighting columns14 Figure 7 Values of factor f715 Figure 8 Cross sections of concrete lighting columns16 Table 1 Partial load factors, gf2 Table 2 Partial material factors, gm4 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10
9、:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5649-7:1985 ii BSI 01-1999 Foreword This Part of BS 5649 has been prepared under the direction of the Road Engineering Standards Committee. BS 5649 has been produced in Parts as the Parts of EN 40 have been produced by the European Committee for Stan
10、dardization Technical Committee CEN/TC 50, Lighting columns and spigots. BS 5649 consists of the following Parts: Part 1: Definitions and terms; Part 2: Dimensions and tolerances; Part 3: Specification for materials and welding requirements; Part 4: Recommendations for surface protection of metal li
11、ghting columns; Part 5: Specification for base compartments and cableways; Part 6: Specification for design loads; Part 7: Method for verification of structural design by calculation; Part 8: Method for verification of structural design by testing; Part 9: Specification for special requirements for
12、reinforced and prestressed concrete columns. CEN/TC 50, however, were unable to agree on a final version of Part 7 “Method for verification of structural design by calculation” and instead had to produce a Unification Report1), which give details of the sections of the draft Part 7 where agreement h
13、ad been reached and highlighted the areas of difference. The British Standards Committee has therefore independently produced this Part of BS 5649. In doing so, the areas that obtained European agreement have been fully incorporated. The remainder of the document contains the information that the UK
14、 delegation of CEN/TC 50 supported, augmented with a limited amount of additional design criteria for door openings that has recently become available from research projects. The method of calculation described in this standard is based on the principles contained in ISO 2394-1973 published by the I
15、nternational Organization for Standardization (ISO). ISO 2394 introduced the concept of limit state design where factored loading effects are compared with the relevant resistance of the structure. BS 5649 has been issued in Parts as they were completed and approved, and until the nine Parts were pu
16、blished it was not possible to supersede the present British Standards for lighting columns. As the Parts were issued, recommendations were given for their implementation together with a list of clauses in the existing standards which they would eventually supersede. With the publication of this Par
17、t, the new standard is complete, and all Parts of the existing standards can be superseded after a suitable transition period. 1) Subsequently published as CEN Report CR 40-7 (May 1984) “Lighting columns, verification of structural design by calculation”. Licensed Copy: sheffieldun sheffieldun, na,
18、Mon Dec 04 16:10:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5649-7:1985 BSI 01-1999iii The British Standards affected by BS 5649 are BS 1308, BS 1840 and BS 3989, specifications for concrete, steel and aluminium street lighting columns, respectively. It is anticipated that BS 1840 and BS 3989
19、will be withdrawn one year from the publication of this Part of this standard and that BS 1308 will be withdrawn three years from the publication of this Part of this standard. In the interim period it is permissible for lighting columns to be specified to comply with either BS 1308, BS 1840, BS 398
20、9 or BS 5649. Purchasers specifying lighting schemes during the interim period should, where possible, permit either alternative. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compl
21、iance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 16, an inside back cover and a back cover. This standard has been updated (see copyright date) and may hav
22、e had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10:44 GMT+00:00 2006,
23、Uncontrolled Copy, (c) BSI BS 5649-7:1985 BSI 01-19991 1 Scope This Part of BS 5649 describes the criteria to be used when verifying the structural design of a lighting column by calculation. It applies to steel and aluminium columns complying with BS 5649-3 and to concrete columns complying with BS
24、 5649-9. It applies to post top columns # 20 m nominal height and to columns with brackets # 18 m nominal height. The calculations are applicable to circular cross sections and regular polygonal cross sections of not less than eight sides. NOTE 1Any changes to the calculations required because of th
25、e use of other cross sections are outside the scope of this standard and should be agreed between the purchaser and the supplier. NOTE 2Care should be taken when applying the formulae detailed in this standard as they include a factor, where appropriate, to produce an answer in the units specified.
26、To assist reference, the major equations are numbered (1) to (14). The structural design of a lighting column can be verified by calculation in accordance with this Part of BS 5649 or, if the manufacturer considers it necessary it can be verified by testing (see BS 5649-8). NOTE 3The titles of the p
27、ublications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Part of BS 5649, the definitions given in BS 5649-1 apply. 3 Symbols The following symbols are used in this Part of BS 5649. The definitions are abbreviated, the full definitions bein
28、g given in the text. aOverall length of door opening. asArea of legs of closed hoops at a section. AeEffective cross-sectional area of door reinforcement. AsCross-sectional area of door reinforcement. bMean dimension of flat side of a polygonal section. boMean dimension of flat side at edge of door
29、opening. BxFactor. ByFactor. CLength of halves of straight edge of door opening. dDiameter of cross section. dlMean diameter of hoop reinforcement. doDiameter of central bore. dwWidth of door reinforcement. EModulus of elasticity. FFactor. gFactor. GModulus of rigidity. hNominal height of lighting c
30、olumn. LEffective length of door opening. moxDistance from centroid of door reinforcement measured normal to the x-x axis. moyDistance from centroid of door reinforcement measured normal to the y-y axis. mxDistance from centre of column wall at the door opening measured normal to the x-x axis. myDis
31、tance from centre of column wall at the door opening measured normal to the y-y axis. MpCombined bending moment for closed regular cross section. MupBending strength for closed regular cross section. MuxBending strength about x-x axis. MuyBending strength about y-y axis. MxBending moment about x-x a
32、xis. MyBending moment about y-y axis. NCorner radius of door opening. PFactor. RMean radius of cross section. sLongitudinal spacing of hoops. SLength of end connection of door reinforcement. tWall thickness. toLesser of t and tw. twThickness of reinforcement. TpTorsional moment. TuTorsional strength
33、. vRadius of gyration of door reinforcement. wBracket projection. ZpPlastic modulus of closed regular cross section. ZpnPlastic modulus of unreinforced door opening cross section about n-n axis. ZpyPlastic modulus of unreinforced door opening cross section about y-y axis. ZpnrPlastic modulus of rein
34、forced door opening cross section about n-n axis. ZpyrPlastic modulus of reinforced door opening cross section about y-y axis. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5649-7:1985 2 BSI 01-1999 4 Basis of calculations The approach
35、to calculations used in this standard is based on limit state principles, where factored load effects are compared with the relevant resistance of the structure; two limit states shall be considered. a) The ultimate limit state, which corresponds to the load-carrying capacity of the column. b) The s
36、erviceability limit state, which relates to the deflection of the column in service. NOTEIn following this approach, simplifications appropriate to lighting columns have been adopted. These are: 1) the number of separate partial safety factors have been reduced to a minimum; 2) serviceability partia
37、l safety factors have been eliminated as these all have a value equal to unity. 5 Strength requirements (ultimate limit state) 5.1 Application of calculations The adequacy of the strength of the column shall be calculated for the following critical cross sections. a) The point at which the column is
38、 fixed. (Normally at ground level.) b) The lower edge of the door opening(s). If two or more door openings are provided, the strength of each opening shall be verified. c) The point at which the bracket begins if the column and bracket consist of one piece, or the point at which the bracket is attac
39、hed if the bracket is detachable. d) Transition from one diameter to another when the column is stepped. e) Any other critical position, e.g. change of material thickness. 5.2 Characteristic loads The characteristic loads for strength requirements shall be the loads calculated in accordance with BS
40、5649-6. 5.3 Characteristic strength of materials 5.3.1 General. The characteristic strength with a statistical probability of 95 % shall be used in the calculation. Where statistical data is not available, the minimum values given in the relevant national or international standard shall be taken as
41、the characteristic strength. 5.3.2 Metal lighting columns. The characteristic strength ss (in N/mm2) of steel and aluminium alloys shall be either: a) the lower yield stress; or b) the 0.2 % proof stress. The values used shall make allowance for any reduction in material strength that may result fro
42、m the jointing process used in the structure. 5.3.3 Concrete lighting columns 5.3.3.1 Concrete. The characteristic strength ss (in N/mm2) of concrete shall be taken as 0.85 of the compressive strength as specified in 3.1 or 4.1 of BS 5649-9:1982, as appropriate. NOTEIn BS 5649-9, the compressive str
43、ength relates to values obtained from test cylinders. 5.3.3.2 Reinforcing and prestressing steels. The characteristic strength ss (in N/mm2) of reinforcing and prestressing steel shall be taken as: a) the elastic limit or 0.2 % proof stress in the case of reinforcing steel; b) the ultimate tensile s
44、trength in the case of prestressing steel. 5.4 Loads to be used for calculations The characteristic loads specified in 5.2 shall be multiplied by the appropriate partial load factors, gf, given in Table 1 to give the loads to be used for calculating bending and torsion moments. Table 1 Partial load
45、factors, gf gfPartial load factor. gmPartial material factor. uHalf angle of door opening. Constant = 3.1416. rFactor. scEffective compressive strength of concrete at transfer of prestress. ssCharacteristic strength of material. stCharacteristic shear strength. spStress on cross section from prestre
46、ssing force after taking account of prestressing losses. f1 to f7Factors as defined in text. LoadPartial load factor, gf Dead loads Wind loads 1.1 1.1 Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:10:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5649-7:1985 BSI 01-19993 5.5 Calculatio
47、n of moments 5.5.1 Bending moments. The bending moments, Mx and My (in Nm), about the orthogonal axes x-x and y-y, respectively, shall be calculated for each position specified in 5.1 using the loads specified in 5.4. For sections with openings, the x-x and y-y axes shall be taken as shown in Figure
48、 4, Figure 5 and Figure 8. NOTEFor polygonal sections, the axes may be positioned through the centre of a flat side or through a corner. For closed regular cross sections, the bending moments Mx and My may be combined to give a single moment, Mp (in Nm) that gives the most adverse action on the colu
49、mn cross section being considered and shall be calculated from the equation: 5.5.2 Torsion moments. On columns with an asymmetric bracket/lantern arrangement the torsion moment, Tp (in Nm) shall be calculated for each position specified in 5.1 using the loads specified in 5.4. 5.6 Strength of section 5.6.1 General. The strength in bending and the strength in torsion of the particular cross section shall be calculated in accordance with 5.6.2 and 5.6.3, as appropriate. Either the strength in bending Mux and Muy (in Nm) shall be
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