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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 8100-3:1999 Incorporat
2、ing Corrigendum No. 1 ICS 91.080.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Lattice towers and masts Part 3: Code of practice for strength assessment of members of lattice towers and masts Licensed Copy: London South Bank University, London South Bank University, Fri D
3、ec 08 06:02:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared under the direction of the Building and Civil Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 September 1999 BSI 03-2001 The fo
4、llowing BSI references relate to the work on this standard: Committee reference B/525/32 Draft for comment 97/10168 DC ISBN 0 580 33033 8 BS 8100-3:1999 Amendments issued since publication Amd. No.DateComments 12097 Corrigendum No. 1 March 2001Indicated by a sideline Committees responsible for this
5、British Standard The preparation of this British Standard was entrusted by Technical Committee B/525, Building and civil enginnering structures, to Subcommittee B/525/32, Towers and masts, upon which the following bodies were represented: British Telecommunications plc Department of Trade and Indust
6、ry (Electricity Department) Institution of Civil Engineers Meteorological Office Ministry of Defence National Transcommunications Ltd Steel Construction Institute UK Steel Association Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 06:02:41 GMT+00:00 2006, Uncon
7、trolled Copy, (c) BSI BS 8100-3:1999 BSI 03-2001i Contents Page Committees responsibleInside front cover Forewordii Introduction1 1Scope1 2Normative references1 3Definitions and symbols1 4Axes of members3 5Structural configurations, system length and effective slenderness3 6Calculation of design str
8、ength for members in compression15 7Calculation of resistance of members in tension17 8Bolted connections17 9Mast guy assemblies20 Annex A (informative) Design of battens24 Annex B (informative) Terminations commonly used for guys24 Annex C (informative) Erection tolerances for guyed masts25 Bibliog
9、raphy26 Figure 1 Typical cable construction2 Figure 2 Dimensions and axes of sections4 Figure 3 Cruciform angle sections5 Figure 4 Typical bracing patterns6 Figure 5 Use of secondary bracing systems7 Figure 6 Typical plan bracing9 Figure 7 K bracing horizontals without plan bracing9 Figure 8 Cranked
10、 K bracing10 Figure 9 Portal frame10 Figure 10 Location of bolts19 Table 1 Applied force as percentage of leg load, F11 Table 2 Effective slenderness factor K for leg members13 Table 3 Effective slenderness factor K for bracing members14 Table 4 Factor K1for horizontal of K brace (without plan braci
11、ng)15 Table 5 Imperfection factors15 Table 6 Reduction factors x16 Table 7 Selection of buckling curve for a cross-section18 Table 8 Relationships between flange, tube and bolts19 Table 9 Range of modulus of elasticity for steel wire guys21 Table B.1 Static tensile efficiencies of terminations25 Lic
12、ensed Copy: London South Bank University, London South Bank University, Fri Dec 08 06:02:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii BSI 03-2001 BS 8100-3:1999 Foreword This part of BS 8100 has been prepared under the direction of Technical Committee B/525, Building and civil engineering struct
13、ures. BS 8100 is a series of standards combining codes of practice with a guide covering the loading and design of lattice towers and masts of metallic construction. It comprises the following parts: Part 1: Code of practice for loading; Part 2: Guide to the background and use of Part 1: Code of pra
14、ctice for loading; Part 3: Code of practice for strength assessment of members of lattice towers and masts; Part 4: Code of practice for loading of guyed masts. This part of BS 8100 incorporates clauses to complement BS 8100-4. The need for this code of practice to give guidance on the determination
15、 of the strength of lattice towers and masts arises out of the difficulty in applying consistently the general structural strength codes to these often tall, slender three dimensional lattice structures. The document is based upon DD 133:1986, which in turn brought together the collective experience
16、 of the European transmission line tower industry, where each new design of structure was subjected to full-scale type testing. It was considered invaluable to have such relatively unique data built into a code as well as enabling the limit state loading rules to be accurately calibrated. The additi
17、onal clauses dealing with the special aspects of guyed masts represent the collective extensive experience of the drafting committee. It is considered that they will provide efficient solutions to the strength assessment problem, whilst avoiding some of the causes of problems which have occurred on
18、this type of structure. By liaison with the relevant Eurocode drafting team, the rules drafted into this code of practice have been based upon a common approach and should result in the minimum amount of variation when the National Application Document is prepared following the issue of the ENV. Thi
19、s part of BS 8100 does not apply to other metallic structures. Other British Standards exist for some of those structures. It has been assumed in the drafting of this British Standard that the execution of its provisions will be entrusted to appropriately qualified and experienced people. As a code
20、of practice, this British Standard takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misleading. Annex A, annex B and annex C are informative. A British Standard does n
21、ot purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside
22、front cover, pages i and ii, pages 1 to 26, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Sidelining in this document indicates the most recent changes by amendment. Licensed Copy: London South Bank University,
23、 London South Bank University, Fri Dec 08 06:02:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 03-20011 BS 8100-3:1999 Introduction The strengths given in this part of BS 8100 are characteristic (95 % probability) values for use with BS 8100-1 and -4. The design strengths are obtained by dividing
24、 the characteristic strengths by the appropriate partial factor gmdefined in this part. Connection eccentricities assumed in this part of BS 8100 are those that are traditionally applied to lattice masts and towers in the UK. 1 Scope This part of BS 8100 provides guidance on the assessment of the st
25、rength of members and connections for masts and towers of lattice construction consisting mainly of bolted, rivetted or welded steel angle or tubular or solid round sections. The recommendations given are valid for both equal and unequal angles, either rolled or cold formed, compound members fabrica
26、ted from these sections, tubular members and solid rounds. The specific components covered in this part of BS 8100 are: a) compression members and bolted and/or welded connections which are specific to typical mast and tower configurations and which are not comprehensively covered in general strengt
27、h codes; b) mast guys, their fittings and assemblies. For such components their strength is closely related to practical considerations, and such guidance is included where relevant. NOTE 1Information on all other aspects of strength assessment can be obtained from BS 5950-1. Information for fatigue
28、 assessment can be obtained from BS 7608. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of this British Standard. For dated references, subsequent amendments to, or revisions of, any of these publ
29、ications do not apply. For undated references, the latest edition of the publication referred to applies. BS 302 (all parts), Stranded steel wire ropes. BS 443, Specification for testing zinc coatings on steel wire and for quality requirements. BS 463, Specification for sockets for steel wire ropes.
30、 BS 643, Specification for white metal ingots for capping steel wire ropes. BS 1554, Specification for stainless and heat-resisting steel round wire. BS 2763, Specification for round carbon steel wire for wire ropes. BS 4429, Specification for rigging screws and turnbuckles for general engineering,
31、lifting purposes and pipe hanger applications. BS 5950-1:1990, Structural use of steelwork in building Part 1: Code of practice for design in simple and continuous construction: hot rolled sections. BS 6994, Specification for steel shackles for lifting and general engineering purposes: grade M(4). B
32、S 7035, Code of practice for socketing of stranded steel wire ropes. 3 Definitions and symbols 3.1 Definitions For the purposes of this part of BS 8100 the following definitions apply. 3.1.1 leg members members forming the main load bearing chords of the structure 3.1.2 primary bracing members membe
33、rs other than legs carrying the shear force due to imposed loads on the structure 3.1.3 secondary members members used to reduce the effective length of the main legs and sometimes that of the bracing. They are normally considered unstressed and are only loaded due to deformation of the structure (s
34、ee 5.4.) NOTESecondary members are sometimes referred to as redundant members. 3.1.4 system length taken as the geometric length of a member between intersection points providing restraint in the relevant plane 3.1.5 mast guy assemblies 3.1.5.1 guy tension only member which provides horizontal suppo
35、rt to the mast column at discrete levels. The lower end of the guy assembly is anchored to the ground and normally incorporates a means of adjusting the tension in the guy NOTEThe terms stay and guy are interchangeable but in this British Standard the word guy has been used throughout. 3.1.5.2 wire
36、individual filament of steel, forming the smallest single tension component in a cable, usually circular in cross section with a diameter between 3 mm and 8 mm, with a high strength that is usually obtained by cold drawing or cold rolling Licensed Copy: London South Bank University, London South Ban
37、k University, Fri Dec 08 06:02:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 BSI 03-2001 BS 8100-3:1999 a) Spiral-strandb) Wire ropes c) Cablesd) Locked-coil Figure 1 Typical cable construction 3.1.5.3 spiral strand assembly of round wires formed helically around a centre wire in one or more symme
38、trical layers NOTEEach successive layer is wound in alternate directions see Figure 1a). 3.1.5.4 wire rope assembly of spiral strands wound helically around a centre core, normally in the opposite direction to the outer layer of the strands see Figure 1b) 3.1.5.5 cable assembly of one or more strand
39、s or ropes of the types described in 3.1.5.3 and 3.1.5.4 NOTEThe strands may be bound in tight contact or kept apart by spacers. See Figure 1c). 3.1.5.6 locked coil strand comprising a central core of round wires, spirally bound with layers of shaped wires NOTEThe inner layers of shaped wires are so
40、metimes of a trapezoidal cross section, but more usually all layers are of Z section wires which overlap and provide a relatively watertight envelope. Each successive layer is wound in alternate directions. See Figure 1d). 3.1.5.7 parallel wire strand assembly of wires laid side by side in parallel
41、and either bound tightly together or with the spaces between the wires held constant by spacer elements 3.1.5.8 core central foundation for the strands, providing support and keeping them in their proper position throughout the life of the rope NOTEFibre cores impregnated with grease are used to pro
42、vide internal lubrication of moving ropes. However, only steel wire cores should be used for mast guys. 3.1.5.9 termination device fixed to the ends of a cable, strand or wire to enable the loads to be transferred between it and the mast column or the steelwork attached to the guy foundation License
43、d Copy: London South Bank University, London South Bank University, Fri Dec 08 06:02:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 03-20013 BS 8100-3:1999 3.2 Symbols For the purposes of this part of BS 8100 the following symbols apply. NOTEThey are based on those given in BS 8100-1 and -4 but i
44、t has not been possible to follow those conventions in all cases. Across-sectional area of the member Ascross-sectional area of bolt in shear plane (shank or threaded section as relevant) (in mm2) Bleg length of angle, i.e. breadth Clength of individual angle between stitch bolts Dbolt, solid round
45、or tube diameter; depth of section Emodulus of elasticity of steel Fleg load jreduction factor Keffective slenderness factor NOTEKL is effective slenderness and Kl is effective slenderness ratio. Llength Ldsystem length of diagonal member Lhsystem length of horizontal member Nthe design buckling res
46、istance of a member P1compressive force in horizontal of K brace P2tensile force in horizontal of K brace Quultimate resistance of bolt rvvradius of gyration about axis vv rxxradius of gyration about axis xx ryyradius of gyration about axis yy tthickness of angle leg, thickness of tube wall xdistanc
47、e from centre line of bolt to end of member ydistance from centre line of bolt to edge of member zspacing between bolts aimperfection factor bratio of effective to gross area lslenderness ratio, i.e. system length divided by radius of gyration Lrelative slenderness (l/l1) Leffeffective slenderness (
48、non- dimensional parameter incorporating K) sbspecified minimum yield strength of bolt steel srreference stress of member stspecified minimum tensile strength of bolt syspecified minimum yield strength of steel member suspecified minimum tensile strength of steel member xreduction factor for relevan
49、t buckling mode 4 Axes of members For the purposes of this part of BS 8100 the axes of members are shown in Figure 2. 5 Structural configurations, system length and effective slenderness 5.1 General There are a number of different configurations that are commonly used in lattice towers and masts. Each requires separate consideration. Some popular arrangements are dealt with in 5.2 and 5.3. In order to determine the buckling resistance of a lattice member it is necessary first to derive the appropriate geometric l