Tiêu chuẩn Châu Âu EC3: Kết cấu thép phần 2: Thiết kế cầu thép (Eurocode3 BS EN1993 2 e 2006 Design of steel structures part 2: Steel bridges)

(1) EN 19932 provides a general basis for the structural design of steel bridges and steel parts of composite bridges. It gives provisions that supplement, modify or supersede the equivalent provisions given in the various parts of EN 19931. (2) The design criteria for composite bridges are covered in EN 19942. (3) The design of high strength cables and related parts are included in EN 1993111. (4) This European Standard is concerned only with the resistance, serviceability and durability of bridge structures. Other aspects of design are not considered. (5) For the execution of steel bridge structures, EN 1090 should be taken into account (6) Execution is covered to the extent that is necessary to indicate the quality of the construction materials and products that should be used and the standard of workmanship needed to comply with the assumptions of the design rules. (7) Special requirements of seismic design are not covered. Reference should be made to the requirements given in EN 1998, which complements and modifies the rules of EN 19932 specifically for this purpose

BRITISH STANDARD BS EN

1993-2:2006

Eurocode 3 — Design of steel structures —

Part 2: Steel bridges

The European Standard EN 1993-2:2006 has the status of a British Standard

ICS 91.010.30; 91.080.10; 93.040

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`,`````,````,`,,`,,,``,,,``,-`-`,,`,,`,`,,` -This British Standard was

published under the authority

of the Standards Policy and

This British Standard was published by BSI It is the UK implementation of

EN 1993-2:2006 It partially supersedes BS 5400-3:2000 This standard will be withdrawn by March 2010 at the latest.

The UK participation in its preparation was entrusted by Technical Committee B/525, Building and civil engineering structures, to Subcommittee B/525/31, Structural use of steel.

A list of organizations represented on B/525/31 can be obtained on request to its secretary.

The structural Eurocodes are divided into packages by grouping Eurocodes for each of the main materials: concrete, steel, composite concrete and steel, timber, masonry and aluminium; this is to enable a common date of withdrawal (DOW) for all the relevant parts that are needed for a particular design The conflicting national standards will be withdrawn at the end of the coexistence period, after all the EN Eurocodes of a package are available Following publication of the EN, there is a period allowed for national calibration during which the National Annex is issued, followed by a coexistence period of a maximum three years During the coexistence period Member States are encouraged to adapt their national provisions Conflicting national standards will be withdrawn by March 2010 at the latest Where a normative part of this EN allows for a choice to be made at national level, the range and possible choice will be given in the normative text, and a note will qualify it as a Nationally Determined Parameter (NDP) NDPs can be a specific value for a factor, a specific level or class, a particular method or a particular application rule if several are proposed in the EN To enable EN 1993-1-11 to

be used in the UK, the NDPs will be published in a National Annex, which will

be made available by BSI in due course after public consultation has taken place.

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations

Amendments issued since publication

Eurocode 3 - Design of steel structures - Part 2: Steel Bridges

Eurocode 3 - Calcul des structures en acier - Partie 2:

Ponts métalliques

Eurocode 3 - Bemessung und konstruktion von Stahlbauten

- Teil 2: Stahlbrücken

This European Standard was approved by CEN on 9 January 2006.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2006 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members.

Ref No EN 1993-2:2006: E

Annex A [informative] – Technical specifications for bearings 50

Annex B [informative] – Technical specifications for expansion joints for road bridges 66

Annex C [informative] – Recommendations for the structural detailing of steel bridge decks 70

Annex D [informative] – Buckling lengths of members in bridges and assumptions for geometrical imperfections 91

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Foreword

This European Standard EN 1993-2, Eurocode 3: Design of steel structures Part 2: Steel bridges, has been prepared by Technical Committee CEN/TC250 « Structural Eurocodes », the Secretariat of which is held by BSI CEN/TC250 is responsible for all Structural Eurocodes

This European Standard shall be given the status of a National Standard, either by publication of an identical text or by endorsement, at the latest by April 2007 and conflicting National Standards shall be withdrawn

at latest by March 2010

This Eurocode supersedes ENV 1993-2

According to the CEN-CENELEC Internal Regulations, the National Standard Organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

Background of the Eurocode programme

In 1975, the Commission of the European Community decided on an action programme in the field of construction, based on article 95 of the Treaty The objective of the programme was the elimination of technical obstacles to trade and the harmonisation of technical specifications

Within this action programme, the Commission took the initiative to establish a set of harmonised technical rules for the design of construction works which, in a first stage, would serve as an alternative to the national rules in force in the Member States and, ultimately, would replace them

For fifteen years, the Commission, with the help of a Steering Committee with Representatives of Member States, conducted the development of the Eurocodes programme, which led to the first generation of European codes in the 1980’s

between the Commission and CEN, to transfer the preparation and the publication of the Eurocodes to the CEN through a series of Mandates, in order to provide them with a future status of European Standard (EN)

This links de facto the Eurocodes with the provisions of all the Council’s Directives and/or Commission’s

Decisions dealing with European standards (e.g the Council Directive 89/106/EEC on construction products – CPD – and Council Directives 93/37/EEC, 92/50/EEC and 89/440/EEC on public works and services and equivalent EFTA Directives initiated in pursuit of setting up the internal market)

The Structural Eurocode programme comprises the following standards generally consisting of a number of Parts:

EN 1990 Eurocode 0: Basis of structural design

EN 1991 Eurocode 1: Actions on structures

EN 1992 Eurocode 2: Design of concrete structures

EN 1993 Eurocode 3: Design of steel structures

EN 1994 Eurocode 4: Design of composite steel and concrete structures

EN 1995 Eurocode 5: Design of timber structures

EN 1996 Eurocode 6: Design of masonry structures

EN 1997 Eurocode 7: Geotechnical design

1 Agreement between the Commission of the European Communities and the European Committee for Standardisation (CEN) concerning the work on EUROCODES for the design of building and civil engineering works (BC/CEN/03/89)

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EN 1998 Eurocode 8: Design of structures for earthquake resistance

EN 1999 Eurocode 9: Design of aluminium structures

Eurocode standards recognise the responsibility of regulatory authorities in each Member State and have safeguarded their right to determine values related to regulatory safety matters at national level where these continue to vary from State to State

Status and field of application of Eurocodes

The Member States of the EU and EFTA recognise that Eurocodes serve as reference documents for the following purposes :

of Council Directive 89/106/EEC, particularly Essential Requirement N°1 - Mechanical resistance and stability - and Essential Requirement N°2 - Safety in case of fire;

ETAs)

The Eurocodes, as far as they concern the construction works themselves, have a direct relationship with the

adequately considered by CEN Technical Committees and/or EOTA Working Groups working on product standards with a view to achieving a full compatibility of these technical specifications with the Eurocodes The Eurocode standards provide common structural design rules for everyday use for the design of whole structures and component products of both a traditional and an innovative nature Unusual forms of construction or design conditions are not specifically covered and additional expert consideration will be required by the designer in such cases

National Standards implementing Eurocodes

The National Standards implementing Eurocodes will comprise the full text of the Eurocode (including any annexes), as published by CEN, which may be preceded by a National title page and National foreword, and may be followed by a National annex (informative)

The National Annex (informative) may only contain information on those parameters which are left open in the Eurocode for national choice, known as Nationally Determined Parameters, to be used for the design of buildings and civil engineering works to be constructed in the country concerned, i.e :

According to Art 12 of the CPD the interpretative documents shall :

a) give concrete form to the essential requirements by harmonising the terminology and the technical bases and indicating classes

or levels for each requirement where necessary ;

b) indicate methods of correlating these classes or levels of requirement with the technical specifications, e.g methods of calculation and of proof, technical rules for project design, etc ;

c) serve as a reference for the establishment of harmonised standards and guidelines for European technical approvals

The Eurocodes, de facto, play a similar role in the field of the ER 1 and a part of ER 2

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Links between Eurocodes and product harmonised technical specifications (ENs and ETAs)

There is a need for consistency between the harmonised technical specifications for construction products

construction products which refer to Eurocodes should clearly mention which Nationally Determined Parameters have been taken into account

Additional information specific to EN 1993-2

EN 1993-2 is the second part of six parts of EN 1993 – Design of Steel Structures – and describes the principles and application rules for the safety and serviceability and durability of steel structures for bridges

EN 1993-2 gives design rules which are supplementary to the generic rules in EN 1993-1-1

EN 1993-2 is intended to be used with Eurocodes EN 1990 – Basis of design, EN 1991 – Actions on structures and the parts 2 of EN 1992 to EN 1998 when steel structures or steel components for bridges are referred to

Matters that are already covered in those documents are not repeated

EN 1993-2 is intended for use by

Numerical values for partial factors and other reliability parameters are recommended as basic values that provide an acceptable level of reliability They have been selected assuming that an appropriate level of workmanship and quality management applies

National annex for EN 1993-2

This standard gives alternative procedures, values and recommendations with notes indicating where national choices may have to be made The National Standard implementing EN 1993-2 should have a National Annex containing all Nationally Determined Parameters to be used for the design of steel structures to be constructed in the relevant country

National choice is allowed in EN 1993-2 through:

1.1.2 Scope of Part 2 of Eurocode 3

composite bridges It gives provisions that supplement, modify or supersede the equivalent provisions given

in the various parts of EN 1993-1

structures Other aspects of design are not considered

NOTE: As long as EN 1090 is not yet available a provisional guidance is given in Annex C

and products that should be used and the standard of workmanship needed to comply with the assumptions of the design rules

given in EN 1998, which complements and modifies the rules of EN 1993-2 specifically for this purpose

1.2 Normative references

publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references the latest edition of the publication applies (including amendments)

product - Technical delivery conditions

systems - Design considerations

EN ISO 9013:2002 Thermal cutting - Classification of thermal cuts - Geometrical product specification and

quality tolerances

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Qualification based on pre-production welding test

procedure test - Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys

1.3 Assumptions

1.4 Distinction between principles and application rules

1.5 Terms and definitions

any end support of a bridge

NOTE: A distinction is made between rigid abutments and flexible abutments where relevant

permanent effect due to controlled forces and /or controlled deformations imposed within a structure

NOTE: Various types of prestress are distinguished from each other as relevant (such as prestress by tendons or

prestress by imposed deformation of supports)

1.5.8

headroom

clear height available for traffic

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1.5.9

breathing (of plates)

out-of-plane deformation of a plate caused by repeated application of in-plane loading

1.5.10

secondary structural elements

structural elements that do not form part of the main structure of the bridge

NOTE: The secondary structural elements are provided for other reasons, such as guard rails, parapets, ladders

and access covers

1.6 Symbols

λ, λ1, λ2, λ3, λ4, λmax, λloc, λglo damage equivalent factors

relieving forces

1.7 Conventions for member axes

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intended purpose, taking into account anticipated maintenance but not major repair

NOTE 1: The National Annex may specify the design working life A design working life of a permanent

bridge of 100 years is recommended

NOTE 2: For temporary bridges the design working life may be stated in the project specifications

protected from excessive deformation, deterioration, fatigue and accidental actions that are expected during the design working life

that plastic deformations of the guardrails or parapets can occur without damaging the structure

replacement should be verified as a transient design situation

Category B or C connection Alternatively closely fitted bolts, rivets or welding may be used to prevent slipping

assessments

NOTE: The National Annex may give additional recommendations for durable details

occurs, the remaining structure can sustain at least the accidental load combination with reasonable means

NOTE: The National Annex may define components that are subject to accidental design situations and also

details for assessments Examples of such components are hangers, cables, bearings

appropriate detailing, see also EN 1993-1-9 and EN 1993-1-10

NOTE 1: EN 1993-1-9, section 3 provides assessment methods using the principles of damage tolerance or safe

and persistent design situations, see 5.4

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see Annex C, and by serviceability checks

2.3 Basic variables

2.3.1 Actions and environmental influences

partial factors for actions see Annex A.2 of EN 1990

NOTE 1: For actions on steel bridge decks of road bridges, see Annex E

NOTE 2: For actions not specified in EN 1991, see the National Annex

NOTE: For actions on bearings, see Annex A

2.3.2 Material and product properties

2.4 Verification by the partial factor method

2.5 Design assisted by testing

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3.2.3 Fracture toughness

design working life of the structure

met for the lowest service temperature

NOTE 1: The lowest service temperature to be adopted in design may be taken from EN 1991-1-5

NOTE 2: The National Annex may specify additional requirements depending on the plate thickness An

example is given in Table 3.1

Table 3.1: Example for additional requirement for toughness of base material

NOTE: The National Annex may give guidance on the selection of toughness properties for members in

compression The use of Table 2.1 of EN 1993-1-10 for σEd = 0,25 fy(t) is recommended

3.2.4 Through thickness properties

required, see EN 1993-1-10

NOTE: Where ZEd values have been determined in accordance with EN 1993-1-10, the required quality class according to EN 10164 may be chosen in the National Annex The choice in Table 3.2 is recommended

Table 3.2: Quality class conforming to EN 10164

Target value ZEd Quality class

should conform with the relevant product standard, ETAG or ETA unless more severe tolerances are specified

3.2.6 Design values of material coefficients

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3.3 Connecting devices

3.3.1 Fasteners

Group 4

and they should be adopted as characteristic values in calculations

Table 3.3: Nominal values of the yield strength fyb and the ultimate tensile

strength fub for bolts

given in EN 1993-1-8, 2.8: Group 4 may be used as preloaded bolts when controlled tightening is carried out

in accordance with the Reference Standards given in EN 1993-1-8, 2.8: Group 7

Standards given in EN 1993-1-8, 2.8: Group 6

Group 1;

Group 4;

3.3.2 Welding consumables

Group 5

grade being welded This should take into account:

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3.4 Cables and other tension elements

NOTE: The National Annex may specify the types of cables appropriate to the specific bridge types

3.5 Bearings

NOTE: The National Annex may give guidance on the types of bearings applicable to bridges

3.6 Other bridge components

technical specifications

NOTE: The National Annex may give guidance on the types of expansion joint, guardrail, parapet and other

ancillary items applicable to bridges

the relevant technical specification

NOTE: The National Annex may give guidance on the bridge deck surfacing system, the products used and the

method of application applicable to bridges

appropriate corrosion allowances should be provided

NOTE: The National Annex may give guidance on sealing against corrosion, measures to ensure air tightness

of box girders or the provisions of extra steel thickness for inaccessible surfaces

carried out in accordance with section 7;

of the bridge should be replaceable These may include:

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5 Structural analysis

5.1 Structural modelling for analysis

5.1.1 Structural modelling and basic assumptions

NOTE: For the design of plated components and cables see also EN 1993-1-5 and EN 1993-1-11

5.1.2 Joint modelling

can be attained

NOTE: Rigid joints appropriate to the fatigue categories given in EN 1993-1-9 are suitable to be employed

between members of bridges except for bearings or pinned connections or cables

5.1.3 Ground structure interaction

satisfied for each section:

cr

I

II M M

α

11

transient design situations

NOTE: The National Annex may give guidance to enable the user to determine when a plastic global analysis

may be used for accidental design situations For plastic global analysis see 5.4 and 5.5 of EN 1993-1-1

5.4.2 Elastic global analysis

ultimate limit state may be ignored

5.5 Classification of cross sections

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6 Ultimate limit states

6.1 General

values of resistance in this section, see Table 6.1:

Table 6.1: Partial factors

a) resistance of members and cross section:

γM3

NOTE 1: For the partial factor γc for the resistance of concrete see EN 1992

NOTE 2: The partial factors γMi for bridges may be defined in the National Annex The following numerical values are recommended:

NOTE: The National Annex may give guidance on the treatment of shear lag effects at the ultimate limit state

in EN 1993-1-5:

1 effective cross section properties of class 4 sections in accordance with EN 1993-1-5, section 4

2 limiting the stress levels to achieve cross section properties in accordance with EN 1993-1-5, section 10

NOTE: The National Annex may recommend which method is to be used In case of the use of the method 2

the National Annex may give further guidance

M

y Rd

c

f A N

γ

b) with local buckling:

0 ,

M

y eff Rd c

f A N

γ

0

lim ,

M

it Rd

c

A N

γ

σ

a) without local buckling:

0 ,

M

y pl Rd c

f W M

γ

0

min , ,

M

y el Rd c

f W M

γ

b) with local buckling:

0

min , ,

M

y eff Rd c

f W M

γ

0

lim min , ,

M

it el

Rd c

W M

γ

σ

distortional deformations, may be taken into account by considering an appropriate elastic model which is subject to the combined effect of bending, torsion and distortion

transverse bending stiffness in the cross section and/or diaphragm action, do not exceed 10 % of the bending effects

distributing effect

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6.2.8 Bending, axial load, shear and transverse loads

of the following two methods:

1 Interaction methods given in 6.2.8 to 6.2.10

NOTE: For local buckling effects see EN 1993-1-5, section 4 to 7

2 Interaction of stresses using the yielding criterion given in 6.2.1

NOTE: For local buckling effects EN 1993-1-5, see section 10

6.2.9 Bending and shear

6.2.10 Bending and axial force

6.2.10.1 Class 1 and class 2 cross sections

lim ,

M y M

it Ed

x

f

γ γ

σ

6.2.10.3 Class 4 cross sections

6.2.11 Bending, shear and axial force

6.3 Buckling resistance of members

6.3.1 Uniform members in compression

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of EN 1993-1-1, class 3 section properties given in equations (6.47), (6.49), (6.50) and (6.52)

of EN 1993-1-1, with stress limits in accordance with section 10 of EN 1993-1-5, may be used, see 6.2.2.5

6.3.2 Uniform members in bending

NOTE: The National Annex may give further information

6.3.3 Uniform members in bending and axial compression

uniform members subject to axial compression and bending in the plane of buckling should be checked in accordance with section 6.3.3 or 6.3.4 of EN 1993-1-1

NOTE: As a simplification to equation (6.61) in 6.3.3 of EN 1993-1-1 the following condition may be used:

9 , 0

1 ,

, ,

,

1

≤

∆ + +

M

Rk y

Ed y Ed

y o mi

M

Rk y

Ed

M

M M

C N N

γ γ

where NEd is the design value of the compression force;

My,Ed is the design value of the maximum moment about the y-y axis of the member obtained from

first order analysis without considering imperfections;

∆My,Ed is the moment due to the shift of the centroidal axis according to 6.2.10.3;

Cmi,o is the equivalent moment factor, see Table A.2 of EN 1993-1-1;

χy is the reduction factors due to flexural buckling from 6.3.1

6.3.4 General method for lateral and lateral torsional buckling of structural components

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NOTE: The National Annex may give the limit of application The values λc, 0 =0,2 and k fl =1,0 (see 6.3.2.4(2) of EN-1993-1-1) are recommended

discrete elastic restraint modelled as springs

NOTE 1: Guidance for determining the stiffness of the restraint in the form of U-frames is given in Annex

D.2.4

NOTE 2: Where truss chords and flanges are restrained by U-frames, the U-frame members are subjected to

forces induced by the restraint and the interaction of the U-frame and the flanges or chords

buckling analysis If continuous springs are used to represent the restraints which are basically discrete, the critical buckling load should not be taken as being larger than that corresponding to the buckling with nodes

at the locations of the restraints

crit

y eff LT

N

f A

=

effect of initial imperfections and second order effects on a supporting spring may be taken into account by

ll

ll

ll

2,11

180

2,1100

k Ed

k Ed

Ed

if N N

N F

if

N F

(6.11)

where

crit k

N

EI

π

= l

ℓ is the distance between the springs

wc eff

A

taken as the effective areas

NOTE: The National Annex may give further guidance for the case where the compressive force NEd is not constant over the length of the chord The following method is recommended

For the bottom flange of a continuous girder with rigid lateral supports at a distance L (see Figure 6.1) m in

equation (6.12) may be taken as the minimum value obtained from the two following values:

m = 1 + 0,44 (1 + µ) Φ1,5 + (0,195 + (0,05 + µ/100) Φ) γ0,5

where µ = V2/V1 , see Figure 6.1

Φ = 2 (1 - M2/M1)/(1 + µ) for M2 > 0 Where the bending moment changes signs, equation (6.14) may be used as a conservative estimate by inserting

M2 = 0

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1 design section

Figure 6.1: Segment of beam between rigid lateral supports with bending moment varying as a

parabola

The verification of resistance to lateral torsional buckling in accordance with 6.3.2.2 may be carried out at a

distance 0,25 Lk from the support with the largest moment as shown in Figure 6.1, provided that the sectional resistance is also checked at the section with the largest moment, where Lk = L m

cross-6.4 Built-up compression members

6.5 Buckling of plates

a) or b) as follows:

a) Direct stresses, shear stresses and transverse forces should be verified according to section 4, 5 or 6 of

EN 1993-1-5 Additionally, the interaction criteria in section 7 of EN 1993-1-5 should also be met

b) Reduced stress method on the basis of stress limits governed by local buckling according to section 10 of

EN 1993-1-5

NOTE: See also 6.2.2.5

moments from loads transverse to the plane of the stiffened plate, the stability may be verified in accordance with 6.3.2.3

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7 Serviceability limit states

7.1 General

a) Restriction to elastic behaviour in order to limit:

b) Limitation of deflections and curvature in order to prevent:

see 7.7 and 7.8;

c) Limitation of natural frequencies, see 7.8 and 7.9, in order to:

using the bridge;

d) Restriction of plate slenderness, see 7.4, in order to limit:

e) Improved durability by appropriate detailing to reduce corrosion and excessive wear, see 7.11

f) Ease of maintenance and repair, see 7.11, to ensure:

asphaltic pavements;

structure

by suitable detailing However in appropriate cases, serviceability limit states may be verified by numerical assessment, e.g for calculating deflections or eigen frequencies

NOTE: The National Annex may give guidance on serviceability requirements for specific types of bridges

7.2 Calculation models

appropriate section properties, see EN 1993-1-5

changes in plate thickness, stiffening etc should be taken into account

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see EN 1993-1-5

NOTE: Simplified calculation models may be used for stress calculations provided that the effects of the

simplification are conservative

7.3 Limitations for stress

making due allowance for the effects of shear lag in flanges and the secondary effects caused by deflections (e.g secondary moments in trusses), should be limited as follows:

ser M

y ser Ed

f

, ,

γ

ser M

y ser

y ser Ed ser Ed

f

,

2 , 2

γ τ

NOTE 1: Where relevant the above checks should include stresses σz from transverse loads, see EN 1993-1-5

NOTE 2: The National Annex may give the value for γMser γMser = 1,00 is recommended

NOTE 3: Plate buckling effects may be ignored as specified in EN 1993-1-5, 2.2(5)

see EN 1993-1-9

combination should be limited to:

EN 1993-1-8), the assessment for serviceability should be carried out using the characteristic load combination

7.4 Limitation of web breathing

fatigue at or adjacent to the web-to-flange connections

NOTE: The National Annex may define cases where web breathing checks are not necessary

stiffened webs, where the following criteria are met:

where L is the span length in m, but not less than 20 m

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1 , 1 1

,

2 , ,

ser Ed x

k

τ σ

σ

τ σ

(7.7)

the length of the panel, see section 4.6(3) of EN 1993-1-5;

EN 1993-1-5;

²]

/[190000

2

mm N b

NOTE: For stresses varying along the panel see EN 1993-1-5, 4.6(3)

7.5 Limits for clearance gauges

under the effects of the characteristic load combination

7.6 Limits for visual impression

be considered

bolts, slip does not need to be considered

7.7 Performance criteria for railway bridges

7.8 Performance criteria for road bridges

7.8.1 General

NOTE: For durability requirements see Annex C

to users

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7.8.2 Deflection limits to avoid excessive impact from traffic

there is no abrupt change in cross section giving rise to impact Sudden changes in the slope of the deck and changes of level at the expansion joints should be eliminated Any transverse girders at the end of the bridge should be designed to ensure that the deflection does not exceed:

NOTE: Guidance on the deflection limit of expansion joints is given in Annex B

piers), the deck area adjacent to these additional deck supports should be designed for the enhanced impact factors given in EN 1991-2 for the area close to the expansion joints

7.8.3 Resonance effects

cable stays or similar components have natural frequencies that are close to the frequency of any mechanical excitation due to regular passage of vehicles over deck joints, consideration should be given to either increasing the stiffness or providing artificial dampers, i.e oscillation dampers

NOTE: Guidance on members supporting expansion joints is given in Annex B

7.9 Performance criteria for pedestrian bridges

should be taken to minimise such vibrations by designing the bridge with appropriate natural frequency or by providing suitable damping devices

7.10 Performance criteria for the effect of wind

stresses of sufficient magnitude that could cause fatigue

NOTE: Guidance on the determination of fatigue loads from vortex excitation is given in EN 1991-1-4

7.11 Accessibility of joint details and surfaces

inspection and maintenance, see ISO 12944-3

such access is not possible, all inaccessible parts should either be effectively sealed against corrosion (e.g the interior of boxes or hollow portions) or they should be constructed in steel with improved atmospheric corrosion resistance Where the environment or access provisions are such that corrosion can occur during the life of the bridge, a suitable allowance for this should be made in the proportioning of the parts see 4(4)

7.12 Drainage

prevent the ingress of water

diameter and slope of the pipes

entering into the structure

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the cleaning openings should be shown on drawings

accumulation of water during leaks or breakage of pipes

self-draining to abutment drainage systems and no further drainage provisions need to be provided along the length of the deck

welding

8 Fasteners, welds, connections and joints

8.1 Connections made of bolts, rivets and pins

8.1.1 Categories of bolted connections

8.1.3 Design resistance of individual fasteners

NOTE: The National Annex may give guidance on the use of hybrid connections

8.1.7 Deductions for fastener holes

8.1.9 Distribution of forces between fasteners at the ultimate limit state

the distance from the centre of rotation

8.2.1.2.2 Intermittent fillet welds

formation of rust pockets

NOTE: Where the connection is protected from weather, e.g in the interior of box sections, intermittent fillet

welds are permitted

NOTE: The National Annex may give further guidance on the use of flare groove welds

8.2.2 Welds with packings

8.2.3 Design resistance of a fillet weld

8.2.4 Design resistance of fillet welds all round

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8.2.5 Design resistance of butt welds

NOTE: The National Annex may give further guidance on the use of eccentrically loaded single fillet or single

sided partial penetration butt welds

8.2.11 Angles connected by one leg

8.2.12 Welding in cold-formed zones

8.2.13 Analysis of structural joints connecting H- and I-sections

5 and 6 of EN 1993-1-8

NOTE: The National Annex may give further guidance on the use of structural joints connecting H- and

I-sections

8.2.14 Hollow section joints

of EN 1993-1-8

NOTE: The National Annex may give further guidance on the use of structural joints connecting hollow

sections

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9 Fatigue assessment

9.1 General

9.1.1 Requirements for fatigue assessment

unless such bridges or parts of them are likely to be excited by wind loads or pedestrians;

loads

9.1.2 Design of road bridges for fatigue

complies with standard requirements for durable structures established through testing

NOTE: The National Annex may give guidance on the conditions where no fatigue assessment is necessary

9.1.3 Design of railway bridges for fatigue

in (2)

NOTE: Elements for which no assessment is needed may be given in the National Annex

1 for bridge decks with longitudinal stiffeners and crossbeams

2 for bridge decks with transverse stiffeners only

9.2.2 Simplified fatigue load model for road bridges

conjunction with the traffic data specified for the bridge location in accordance with EN 1991-2 should be applied

NOTE: See also 9.4.1(6)

9.2.3 Simplified fatigue load model for railway bridges

9.3 Partial factors for fatigue verifications

NOTE: The National Annex may give the value for γFf The use of γ Ff = 1,0 is recommended

NOTE: The National Annex may give values for γMf The values given in Table 3.1 of EN 1993-1-9 are recommended

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9.4 Fatigue stress range

9.4.1 General

determine the design stress range

areas

be obtained from:

taken as equal to 1,0, as it is included in the fatigue load model

evaluation of stress history from the fatigue load vehicles as specified in EN 1991-2, see EN 1993-1-9

NOTE: The National Annex may give guidance on the use of EN 1991-2

9.4.2 Analysis for fatigue

continuous beams on elastic supports

NOTE: For railway bridges longitudinal stiffeners may be analysed as continuous beams on elastic supports

NOTE: Where crossbeams are provided with cut outs as given in Figure 9.3, the action effects may be

determined with a Vierendeel-model (where the deckplate and a part of the crossbeam below the cut outs are the flanges and the areas between the cut outs are the posts)