1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21313-8 SANS 10326:2008Edition 1.1Any reference to SABS 0326 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 N
4、ovember 2002)SOUTH AFRICAN NATIONAL STANDARD Structural bearings The design of bridge bearings Published by SABS Standards Division 1 dr lategan road groenkloof private bag X191 pretoria 0001 tel: +27 12 428 7911 fax: +27 12 344 1568 www.sabs.co.za SABS SANS 10326:2008 Edition 1.1 Table of changes C
5、hange No. Date Scope Amdt 1 2008 Amended to change the designation of SABS standards to SANS standards and to update the referenced standards. Foreword This South African standard was approved by National Committee SABS TC 4, Bearings, in accordance with procedures of the SABS Standards Division, in
6、 compliance with annex 3 of the WTO/TBT agreement. This document was published in August 2008. This document supersedes SABS 0326:2000 (edition 1). A vertical line in the margin shows where the text has been technically modified by amendment No. 1. This document forms part of a set of two standards
7、on bridge bearings, viz SANS 10326, Structural bearings The design of bridge bearings. SANS 1806, Structural bearings Bridge bearings Materials, manufacture and installation. Annex A forms an integral part of this document. SANS 10326:2008 Edition 1.1 1 Contents Page Foreword 1 Scope . 3 2 Normative
8、 references . 3 3 Definitions and symbols . 5 3.1 Definitions . 5 3.2 Symbols 10 4 Function of bearings . 12 5 Design considerations 12 5.1 General . 12 5.2 Limit state requirements 12 5.3 Design life . 13 5.4 Provision for replacement and resetting . 13 5.5 Provision for handling 13 5.6 Access . 13
9、 5.7 Durability . 15 5.8 Movement restraint . 15 5.9 Uplift 15 5.10 Outer bearing plates or spreader plates . 15 5.11 Use of different types of bearing . 16 5.12 Positioning of bearings 16 5.13 Effects of variation within tolerances . 16 5.14 Loads and load effects 16 5.15 Movements 19 5.16 Material
10、s 19 5.17 Bearing schedule 19 6 Particular recommendations for the roller and the rocker bearings . 20 6.1 General . 20 6.2 Allowable loads on steel and cast iron roller and the rocker bearings . 20 6.3 Flat-sided rollers . 21 6.4 Non-cylindrical roller . 21 6.5 Multiple rollers 22 7 Particular reco
11、mmendations for the knuckle bearings 22 7.1 General . 22 7.2 Pins . 22 7.3 Allowable bearing pressures for the knuckle bearings . 22 SANS 10326:2008 Edition 1.1 2 Contents (concluded) Page 8 Particular recommendations for the plane sliding bearings 23 8.1 Function 23 8.2 Sliding surfaces 23 8.3 Arra
12、ngement of sliding surfaces 23 8.4 Prevention of rotation . 23 9 Particular recommendations for sliding elements with PTFE 23 9.1 Surface sliding on PTFE 23 9.2 Location of PTFE 23 9.3 Allowable sliding bearing pressures for pure PTFE 24 9.4 Thickness of stainless steel sliding surfaces . 25 9.5 Fix
13、ing of stainless steel 25 10 Particular recommendations for the elastomeric bearings 25 10.1 General . 25 10.2 Shear strain 26 10.3 Shape factor . 27 10.4 Moduli of the elastomer 28 10.5 Design pressure on plain pad and strip bearings 29 10.6 Maximum design strain in laminated bearings 29 10.7 Reinf
14、orcing plate thickness 31 10.8 Stability . 31 10.9 Vertical deflection . 32 10.10 Rotational limitation 33 10.11 Fixing of bearings . 33 11 Particular recommendations for the pot bearings . 34 11.1 Function 34 11.2 Design . 34 11.3 Rotation . 34 11.4 Seal . 34 12 Particular recommendations for guide
15、s 34 12.1 Function 34 12.2 Sliding surfaces for guides . 35 12.3 Allowable bearing pressures on guides . 35 Annex A Typical bridge bearing schedule . 36 SANS 10326:2008 Edition 1.1 3 Structural bearings The design of bridge bearings 1 Scope 1.1 This code of practice gives recommendations for the des
16、ign and performance of the most common types of bridge bearings. It shall be read in conjunction with SANS 1806; those parts of TMH 7 which deal with loading and design of concrete and composite bridges; and those parts of BS 5400 which cover design, materials and workmanship of steel bridges. The r
17、ecommendations given in this code of practice are appropriate only when the materials and workmanship comply with the requirements of SANS 1806, BS 5400-3, BS 5400-4 and BS 5400-6. NOTES 1 This code does not cover concrete hinges and special bearings for moving bridges, for example swing and lift br
18、idges. 2 The principles given in this code can also be applied to structures other than bridges. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to a
19、ny of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative documents referred t
20、o applies. Information on currently valid national and international standards and other publications can be obtained from the SABS Standards Division. BS 903-A26, Physical testing of rubber Part A26: Method for determination of hardness (hardness between 10 IRHD and 100 IRHD). Amdt 1 BS 970-1, Spec
21、ification for wrought steels for mechanical and allied engineering purposes Part 1: General inspection and testing procedures and specific requirements for carbon, manganese, alloy and stainless steels (superseded by BS EN 10095). Amdt 1 BS 970-2, Specification for wrought steels for mechanical and
22、allied engineering purposes Part 2: Requirements for steels for the manufacture of hot formed springs. Amdt 1 BS 970-3, Specification for wrought steels for mechanical and allied engineering purposes Part 3: Bright bars for general engineering purposes. Amdt 1 SANS 10326:2008 Edition 1.1 4 BS 5400-3
23、, Steel, concrete and composite bridges Part 3: Code of practice for design of steel bridges. BS 5400-4, Steel, concrete and composite bridges Part 4: Code of practice for design of concrete bridges. BS 5400-6, Steel, concrete and composite bridges Part 6: Specification for materials and workmanship
24、, steel. BS 7668, Weldable structural steels Hot finished structural hollow sections in weather resistant steels Specification. EN 1563, Founding Spheroidal graphite cast irons. EN 1564, Founding Austempered ductile cast irons. EN 10003-1, Metallic materials Brinell hardness test Part 1: Test method
25、. Amdt 1 EN 10025-1, Hot rolled products of structural steels Part 1: General technical delivery conditions. Amdt 1 EN 10025-6, Hot rolled products of structural steels Part 6: Technical delivery conditions for flat products of high yield strength structural steels in the quenched and tempered condi
26、tion. Amdt 1 EN 10084, Case hardening steels Technical delivery conditions. EN 10087, Free-cutting steels Technical delivery conditions for semi-finished products, hot-rolled bars and rods. EN 10089, Hot-rolled steels for quenched and tempered springs. Technical delivery conditions. Amdt 1 EN 10090,
27、 Valve steels and alloys for internal combustion engines. EN 10095, Heat-resisting steel and nickel alloys. EN 10137-1, Plates and wide flats made of high yield strength structural steels in the quenched and tempered or precipitation hardened conditions Part 1: General delivery conditions. Amdt 1 EN
28、 10137-2, Plates and wide flats made of high yield strength structural steels in the quenched and tempered or precipitation hardened conditions Part 2: Delivery conditions for quenched and empered steels. Amdt 1 EN 10137-3, Plates and wide flats made of high yield strength structural steels in the q
29、uenched and tempered or precipitation hardened conditions Part 3: Delivery conditions for precipitation hardened steels. Amdt 1 EN 10277-2, Bright steel products Technical delivery conditions Part 2: Steels for general engineering purposes. Amdt 1 SANS 1806, Structural bearings Bridge bearings Mater
30、ials, manufacture and installation. SANS 6506-1/ISO 6506-1, Metallic materials Brinell hardness test Part 1: Test method. Amdt 1 SANS 10048/ISO 48, Rubber, vulcanized or thermoplastic Determination of hardness (hardness between 10 IRHD and 100 IRHD). Amdt 1 SANS 10326:2008 Edition 1.1 5 TMH 7-1, Tec
31、hnical methods for highways Code of practice for the design of highway bridges and culverts Part 1: General statements. TMH 7-2, Technical methods for highways Code of practice for the design of highway bridges and culverts Part 2: Specification for loads. TMH 7-3, Technical methods for highways Cod
32、e of practice for the design of highway bridges and culverts Part 3: Design of concrete structures. 3 Definitions and symbols 3.1 Definitions For the purpose of this code of practice the definitions given in SANS 1806 and those given in TMH 7 for design loads (actions) and design load (action) effec
33、ts and the following definitions apply: 3.1.1 elastomer a compound that contains natural rubber (NR) or chloroprene rubber (CR) with elastic properties 3.1.2 elastomeric bearing a bearing that comprises a block of elastomer that may or may not be reinforced internally with steel plates. Examples of
34、elastomeric bearings are: a) laminated bearing: An elastomeric bearing that is reinforced with steel plates (see figure 1); b) plain pad bearing: An un-reinforced elastomeric bearing; and c) strip bearing: A plain pad bearing for which the length is at least ten times the width. Figure 1 Elastomeric
35、 laminated bearing 3.1.3 knuckle bearings a bearing that consists essentially of two or more members with mating curved surfaces. The curved surfaces may be cylindrical or spherical. These bearings permit rotation by the sliding of one part on another (see figures 2, 3, 4 and 5) SANS 10326:2008 Edit
36、ion 1.1 6 Figure 2 Pin bearing Figure 3 Cylindrical bearing SANS 10326:2008 Edition 1.1 7 Figure 4 Spherical bearing Figure 5 Leaf bearing 3.1.4 pot bearing a bearing that consists essentially of a metal piston supported by a disc of unreinforced elastomer that is confined within a metal cylinder (s
37、ee figure 6) SANS 10326:2008 Edition 1.1 8 Figure 6 Pot bearing 3.1.5 rocker bearing a bearing that consists essentially of a curved surface in contact with a flat or curved surface and, constrained to prevent relative horizontal movement. The curved surfaces may be cylindrical or spherical. Rocker
38、bearings permit rotation by the rolling of one part on another (see figures 7 and 8) Figure 7 Linear rocker bearing SANS 10326:2008 Edition 1.1 9 Figure 8 Point rocker bearing 3.1.6 roller bearing a bearing that consists essentially of one or more rollers between parallel upper and lower plates (see
39、 figures 9 and 10) Figure 9 Single roller bearing SANS 10326:2008 Edition 1.1 10 Figure 10 Multiple roller bearing 3.1.7 sliding bearing a bearing that consists essentially of two surfaces which slide on one another (see figure 11) Figure 11 Plane Sliding bearing 3.2 Symbols The symbols used in this
40、 code of practice are as follows: A is the overall plan area of the elastomeric bearing Aeis the effective plan area of the elastomeric bearing A1is the reduced effective plan area of the elastomeric bearing b is the overall width of the bearing (the shorter dimension of a rectangular bearing) beis
41、the effective width of the elastomeric bearing E is the modulus of the elasticity SANS 10326:2008 Edition 1.1 11 Ebis the bulk modulus of the elastomer G is the shear modulus of the elastomer H is the horizontal force k is a factor (see 10.6) L is the overall length of the bearing (the longer dimens
42、ion of a rectangular bearing) Leis the effective length of the elastomeric bearing Lpis the force-free perimeter of the elastomeric bearing F* is the design load (action) (refer TMH 7) R is the radius of the cylinder or the sphere or the convex surface R1is the radius of the concave surface S is the
43、 shape factor of the elastomer slab S1is the shape factor of the thickest elastomer layer S2are the design load (action) effects T is the minimum shade of the air temperature t is the thickness of a plain pad or strip bearing t1and t2are the thicknesses of the adjacent elastomer layers teis the effe
44、ctive thickness of the elastomer in compression tiis the thickness of an individual elastomer layer in a laminated bearing tqis the total thickness of the elastomer in shear V is the vertical design load (action) effect bis the angular rotation across width b of the bearing Lis the angular rotation
45、across length L of the bearing f3is a partial safety factor fLis a partial load factor m is a partial material factor is the total vertical deflection is the vertical deflection of an individual elastomer layer b is the maximum horizontal relative displacement of the parts of the bearing in the dire
46、ction of dimension b of the bearing SANS 10326:2008 Edition 1.1 12 Lis the maximum horizontal relative displacement of the parts of the bearing in the direction of dimension L of the bearing ris the maximum resultant horizontal relative displacement of parts of bearing obtained by vectorial addition
47、 of band ICis the nominal strain in the elastomer slab due to compressive loads qis the shear strain in the elastomer slab due to translational movement tis the total nominal strain in the elastomer slab is the nominal strain in elastomer due to angular rotation uis the nominal ultimate tensile stre
48、ngth of material sis the stress in the steel NOTE It is essential that the units used for these symbols in the formulae are compatible with each other so that the results of the formulae are in the desired units. 4 Function of bearings The function of bearings is to provide a connection to control t
49、he interaction of loadings and movements between parts of a structure, usually between the superstructure and the substructure. A guide to the suitability of various types of bearing for different functions is given in table 1. To achieve the required degree of freedom it may be necessary to combine the characteristics of different types of bearing, the resultant bearing as a whole providing the required movements and load resistance, for example a plane sliding bearing t
