Eurocode 5: Design of timber structures

Size: px

Start display at page:

Download "Eurocode 5: Design of timber structures"

Felicity Wilson
6 years ago
Views:

1 BRITISH STANDARD Eurocode 5: Design of timber structures BS EN : A1:2008 Incorporating corrigendum June 2006 Part 1-1: General Common rules and rules for buildings ICS ;

2 National foreword This British Standard was published under the authority of the Standards Policy and Strategy Committee on 15 December 2004 This British Standard is the UK implementation of EN :2004+A1:2008, incorporating corrigendum June It supersedes BS EN :2004 which is withdrawn. The start and finish of text introduced or altered by amendment is indicated in the text by tags. Tags indicating changes to CEN text carry the number of the CEN amendment. For example, text altered by CEN amendment A1 is indicated by!". The structural Eurocodes are divided intopackages by groupin geurocodes for each of the main materials, concrete, steel, composite concrete and steel, timber, masonry and aluminium, which 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 The conflicting national standards will be withdrawn at the end of the coexistence period, after all the EN Eurocodes of a package are available.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 of 2 years allowed for the national calibration period during which the National Annex is issued, followed by a three year coexistence period. During the coexistence period Member States will be encouraged to adapt their national provisions to withdraw conflicting national rules before the end of the coexistent period. The Commission in consultation with Member States is expected to agree the end of the coexistence period for each package of Eurocodes. At the end of this coexistence period, the national standard(s) will be withdrawn. In the UK, the corresponding national standards are: BS :2002, Structural use of timber Part 2: Code of practice for permissible stress design, materials and workmanship; BS :1998, Structural use of timber Part 3: Code of practice for trussed rafter roofs; BS :1996, Structural use of timber Part 6: Code of practice for timber frame walls Section 6.1: Dwellings not exceeding four storeys; BS :2002, Structural use of timber Part 6: Code of practice for timber frame walls Section 6.2: Buildings other than dwellings not exceeding four storeys; BS :1989, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Section 7.1: Domestic floor joists; BS :1989, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Section 7.2: Joists for flat roofs; BS :1989, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Section 7.3: Ceiling joists; BS :1989, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Part 7.4: Ceiling binders; BS :1990, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Section 7.5: Domestic rafters; BS :1990, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Section 7.6: Purlins supporting rafters; Amendments/corrigenda issued since publication Amd. No. Date Comments BSI 2009 ISBN Corrigendum No July 2006 Implementation of CEN corrigendum June Modifications to 6.5.2, 8.2.2, and January 2009 Implementation of CEN amendment A1:2008

3 BS :1990, Structural use of timber Part 7: Recommendations for the calculation basis for span tables Section 7.7: Purlins supporting sheeting or decking; and based on this transition period, these standards will be withdrawn on a date to be announced. The UK participation in its preparation was entrusted by Technical Committee B/525, Building and civil engineering structures, to Subcommittee B/525/5, Structural use of timber. Alist of organizations represented on this subcommittee can be obtained on request to its secretary. Where a normative part of this EN allows for a choice to be made at the national level, therange and possible choice will be given inthe 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 to be used in the UK, the NDPs will be publis hed 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. i

4 blank

5 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN :2004+A1 June 2008 ICS ; Incorporating corrigendum June 2006 Supersedes ENV :1993 English version Eurocode 5: Design of timber structures - Part 1-1: General - Common rules and rules for buildings Eurocode 5: Conception et calcul des structures en bois - Partie 1-1 : Généralités - Règles communes et règles pour les bâtiments Eurocode 5: Bemessung und Konstruktion von Holzbauten - Teil 1-1: Allgemeines - Allgemeine Regeln und Regeln für den Hochbau This European Standard was approved by CEN on 16 April 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 tra nslation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as t he 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, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2004 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN :2004: E

6 EN : A1:2008 (E) Contents Page Foreword 7 SECTION 1 GENERAL S COPE Scope of EN Scope of EN N ORMATIVE REFERENCES A SSUMPTIONS D ISTINCTION BETWEEN P RINCIPLES AND A PPLICATION R ULES T ERMS AND DEFINITIONS General Additional terms and definitions used in this present standard S YMBOLS USED IN EN SECTION 2 BASIS OF DESIGN R EQUIREMENTS Basic requirements Reliability management Design working life and durability P RINCIPLES OF LIMIT STATE DESIGN General Ultimate limit states Serviceability limit states B ASIC VARIABLES Actions and environmental influences General Load-duration classes Service classes Materials and product properties Load-duration and moisture influences on strength Load-duration and moisture influences on deformations V ERIFICATION BY THE PARTIAL FACTOR METHOD Design value of material property Design value of geometrical data Design resistances Verification of equilibrium (EQU) 25 SECTION 3 MATERIAL PROPERTIES G ENERAL Strength and stiffness parameters Stress-strain relations Strength modification factors for service classes and load-duration classes Deformation modification factors for service classes S OLID TIMBER G LUED LAMINATED TIMBER L AMINATED VENEER LUMBER (LVL) W OOD-BASED PANELS A DHESIVES M ETAL FASTENERS 29 SECTION 4 DURABILITY R ESISTANCE TO BIOLOGICAL ORGANISMS R ESISTANCE TO CORROSION 30 SECTION 5 BASIS OF STRUCTURAL ANALYSIS G ENERAL 31 2

7 EN : A1:2008 (E) 5.2 M EMBERS C ONNECTIONS A SSEMBLIES General Frame structures Simplified analysis of trusses with punched metal plate fasteners Plane frames and arches 34 SECTION 6 ULTIMATE LIMIT STATES D ESIGN OF CROSS-SECTIONS SUBJECTED TO STRESS IN ONE PRINCIPAL DIRECTION General Tension parallel to the grain Tension perpendicular to the grain Compression parallel to the grain Compression perpendicular to the grain Bending Shear Torsion D ESIGN OF CROSS-SECTIONS SUBJECTED TO COMBINED STRESSES General Compression stresses at an angle to the grain Combined bending and axial tension Combined bending and axial compression 6.3 S TABILITY OF MEMBERS General Columns subjected to either compression or combined compression and bending Beams subjected to either bending or combined bending and compression D ESIGN OF CROSS-SECTIONS IN MEMBERS WITH VARYING CROSS-SECTION OR CURVED SHAPE General Single tapered beams Double tapered, curved and pitched cambered beams N OTCHED MEMBERS General Beams with a notch at the support S YSTEM STRENGTH 50 SECTION 7 SERVICEABILITY LIMIT STATES 7.1 JOINT SLIP 7.2 L IMITING VALUES FOR DEFLECTIONS OF BEAMS 7.3 V IBRATIONS General Vibrations from machinery Residential floors SECTION 8 CONNECTIONS WITH METAL FASTENERS 8.1 G ENERAL Fastener requirements Multiple fastener connections Multiple shear plane connections Connection forces at an angle to the grain Alternating connection forces LATERAL LOAD-CARRYING CAPACITY OF METAL DOWEL-TYPE FASTENERS General Timber-to-timber and panel-to-timber connections Steel-to-timber connections N AILED CONNECTIONS Laterally loaded nails

8 EN : A1:2008 (E) General Nailed timber-to-timber connections Nailed panel-to-timber connections Nailed steel-to-timber connections Axially loaded nails Combined laterally and axially loaded nails S TAPLED CONNECTIONS BOLTED CONNECTIONS Laterally loaded bolts General and bolted timber-to-timber connections Bolted panel-to-timber connections Bolted steel-to-timber connections Axially loaded bolts D OWELLED CONNECTIONS S CREWED CONNECTIONS Laterally loaded screws Axially loaded screws Combined laterally and axially loaded screws 8.8 C ONNECTIONS MADE WITH PUNCHED METAL PLATE FASTENERS General Plate geometry Plate strength properties Plate anchorage strengths Connection strength verification Plate anchorage capacity Plate capacity S PLIT RING AND SHEAR PLATE CONNECTORS TOOTHED-PLATE CONNECTORS 84 SECTION 9 COMPONENTS AND ASSEMBLIES 9.1 C OMPONENTS Glued thin-webbed beams Glued thin-flanged beams Mechanically jointed beams Mechanically jointed and glued columns 9.2 A SSEMBLIES Trusses Trusses with punched metal plate fasteners Roof and floor diaphragms General Simplified analysis of roof and floor diaphragms Wall diaphragms General Simplified analysis of wall diaphragms Method A Simplified analysis of wall diaphragms Method B Construction of walls and panels to meet the requirements of the simplified analysis Design procedure Bracing General Single members in compression Bracing of beam or truss systems 101 SECTION 10 STRUCTURAL DETAILING AND CONTROL 10.1 G ENERAL 10.2 M ATERIALS 10.3 G LUED JOINTS 10.4 C ONNECTIONS WITH MECHANICAL FASTENERS General Nails Bolts and washers

9 EN : A1:2008 (E) Dowels Screws A SSEMBLY T RANSPORTATION AND ERECTION C ONTROL S PECIAL RULES FOR DIAPHRAGM STRUCTURES Floor and roof diaphragms Wall diaphragms SPECIAL RULES FOR TRUSSES WITH PUNCHED METAL PLATE FASTENERS Fabrication Erection 106 ANNEX A (INFORMATIVE): BLOCK SHEAR AND PLUG SHEAR FAILURE AT MULTIPLE DOWEL-TYPE STEEL-TO-TIMBER CONNECTIONS ANNEX B B.1 S B.1.1 B.1.2 B.1.3 B.1.4 B.2 E B.3 N B.4 M B.5 F (INFORMATIVE): MECHANICALLY JOINTED BEAMS IMPLIFIED ANALYSIS Cross-sections Assumptions Spacings Deflections resulting from bending moments C.1 G ENERAL C.1.1 Assumptions C.1.2 Load-carrying capacity C.2 M ECHANICALLY JOINTED COLUMNS C.2.1 Effective slenderness ratio C.2.2 Load on fasteners C.2.3 Combined loads 115 C.3 S PACED COLUMNS WITH PACKS OR GUSSETS 115 C.3.1 Assumptions 115 C.3.2 Axial load-carrying capacity 116 C.3.3 Load on fasteners, gussets or packs 117 C.4 LATTICE COLUMNS WITH GLUED OR NAILED JOINTS 117 C.4.1 Assumptions 117 C.4.2 Load-carrying capacity 118 C.4.3 Shear forces 120 ANNEX D (INFORMATIVE): BIBLIOGRAPHY 108 FFECTIVE BENDING STIFFNESS 112 ORMAL STRESSES 112 AXIMUM SHEAR STRESS 112 ASTENER LOAD 112 ANNEX C (INFORMATIVE): BUILT-UP COLUMNS 121 5

Eurocode 5: Design of timber structures

BRITISH STANDARD Eurocode 5: Design of timber structures BS EN 1995-1-2:2004 Incorporating corrigenda June 2006 and March 2009 Part 1-2: General Structural fire design ICS 13.220.50; 91.010.30; 91.080.20