PUBLISHEDDOCUMENT
BackgroundtotheNational AnnextoBSEN1991-2
Traffic loads on bridges
NO COPYING WVITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAVW
BSI 2011
ISBN 978 0 580 58680 4
ICS 91.010.30; 93.040
Publication historyFirst published March 2011
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The BSI copyright notice displayed in this document indicates when the document was last issued.
The following BSI reference relates to the work on this standard:Committee reference B/525/10
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Contents
Forewordi
Annexes
Bibliography 19
List of figures
List of tables
Summary of pages
2 1 Scope1 Normative references 13 BS EN 1991-2:2003 Eurocode 1: Actions on structures Part 2:Traffic loads on bridges 1
Annex A (informative) Vibration serviceability remendations forfoot and cycle track bridges 11
Figure 1 Comparison of pedestrian load intensity (excluding crowdloading) variation with loaded length for road (and rail) bridges supporting footways or cycle tracks and for footbridges8Figure 2 Reduction factor 入 to allow for the unsynchronizedbination of pedestrian actions within groups and crowds10 Figure A.1 - Synthetic time history for a random bridge/pedestrianmodel13 Figure A.2 - Reduction of pedestrian speed and flow rates withdensity 14Figure A.4- Dynamic response factor 16 Figure A.3 -Configuration factor K15
Table A.1 - Typical values of logarithmic decrement of decay of Table 1-Loading classes 6vibration (8) between successive peaks 11
Foreword
Publishing information
Relationship with other publications
Presentational conventions
Contractual and legal considerations
This Published Document is published by BSI and came into effect onunder the authority of Technical Committee B/525 Building and civilengineering. A list of organizations represented on this mitteecan be obtained on request to its secretary.
This Published Document is a background paper that givesnon-contradictory plimentary information for use in the UK with the Eurocode for actions on structures BS EN 1991-2 and itsUK National Annex.
BS 5400-2 has been withdrawn and superseded by BS EN 1990 BS EN 1991-2 and BS EN 1991-1-7. References to BS 5400-2 in thisPublished Document are informative only and are included to provide readers with a parison between the withdrawn British Standardand the current Eurocodes.
The following standlards BS EN 1991-1-3 BS EN 1991-1-4 BS EN 1991-1-5and BS EN 1991-1-6 should be consulted when designing bridges.
The word *should" is used to express remendations of this Published Document. The word *may" is used in the text to expressof the clause. The word “cana is used to express possibility e.g. a permissibility e.g. as an alternative to the primary remendationconsequence of an action or an event.
Notes and mentaries are provided throughout the text of thisstandard. Notes give references and addlitional information that are important but do not form part of the remendations. Commentariesgive background information.
This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.
Compliance with a Published Document cannot confer immunity fromlegal obligations.
1 Scope
2Normativereferences
AdjustmentfactorβforLM2 [BS EN 1991-2:2003 4.3.3 (2)]
This Published Document gives non-contradictory plementaryinformation on traffic loads on bridges for use in the UK in conjunction with BS EN 1991-2 and its UK National Annex.
The following referenced documents are indispensable for theapplication of this document.For datedreferences only theedition cited applies. For undated references the latest edition of thereferenced document (including any amendments) applies.
BS EN1990:2002 Eurocode Basis of structural design
BS EN 1991-2:2003 Eurocode 1: Actions on structures Part 2: Traffic loads on bridges
NA to BS EN 1990:2002A1:2005 UK Nationa/ Annex for Eurocode Basis of structural design
on structures Part 2: Traffic loads on bridges NA to BS EN 1991-2:2003 UK Nationa/ Annex to Eurocode 1: Actions
3BSEN1991-2:2003 Eurocode1:Actionson structures-Part2:Trafficloadsonbridges
3.1 Modelsforloadedlengthsgreaterthan200m [BS EN 1991-2:2003 4.1(1) Note 2]
was given in BS 5400-2 (BD 37/01 1 [1]) and Load Model 1 (LM1) in A study has been carried out to pare type HA loading thatBS EN 1991-2 with the parameters given in the UK National Annex. The LM1 effects are within the acceptable range for spans up to1500 m. It is concluded that assuming type HA loading in BS 5400-2was suitable for bridges with a span up to 1500 m the application of LM1 is appropriate for bridges up to 1 500 m loaded length.
3.2 AdjustmentfactorsoforLM1 [BS EN 1991-2:2003 4.3.2(3) Notes 1and 2]
been derived based on calibration against HA serviceability limit state The values given in the NA to BS EN 1991-2:2003 Table NA.1 have(SLS) loading from BS 5400-2 and verified using reliability analysis (see Atkins' Background to the UK National Annexes to BS EN 1990 y yauao pasn aq pnous bupe s1 () z66 N3 sg puepartial factors given in the NA to BS EN 1990:2002A1.
The NA to BS EN 1991-2 NA.2.14 provides for a wheel load of 200 kN6.2.5. However the wheel contact area has been adjusted as in the pared with the 100 kN load that was given in BS 5400-2:2006
