EN 16481:2014
(Main)Timber stairs - Structural design - Calculation methods
Timber stairs - Structural design - Calculation methods
This European Standard constitutes a frame standard for the design of timber stairs as well as wood and wood-based components used in stairs by calculation methods. Some calculation methods can be derived from testing results, for example CEN/TS 15680. This document specifies the design and the requirements for materials and components to be used in these calculation methods. It may be complemented by national application documents based on this European Standard.
This European Standard applies to coated and uncoated components. This document covers load-bearing components such as strings, treads, risers, posts and guardrails. Requirements for a timber stair are defined in the product standard, EN 15644. This document does not cover stairs that contribute to the overall stability of the works or the strength of the structure.
This European Standard is valid for the verification of mechanical performance characteristics, usability and load-bearing capacity and their related durability. Other requirements, e.g. requirements for acoustic properties, are not covered by this European Standard.
For the design, calculation and determination of not solely resting actions, additional requirements need to be taken into account (to be checked).
For the dimensioning with special reference to resistance to fire and earthquake/seismic action, additional requirements may be taken into account.
Without further verification, the methods in this European Standard are valid for different types of stair structures and their components, as illustrated in Figure 1:
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Holztreppen - Bauplanung - Berechnungsmethoden
Diese Europäische Norm legt als Rahmennorm Berechnungsmethoden für die Konstruktion von Holztreppen sowie für Bauteile aus Holz und Holzwerkstoffen fest, die für Treppen verwendet werden. Einige Berech-nungs¬methoden können von Prüfergebnissen abgeleitet werden, z. B. CEN/TS 15680. Dieses Dokument legt die Konstruktion von und die Anforderungen an Werkstoffe(n) und Bauteile(n) fest, die in diesen Berechnungsmethoden zu verwenden sind. Sie darf durch Nationale Anwendungsdokumente ergänzt werden, die auf dieser Europäischen Norm beruhen.
Diese Europäische Norm gilt für beschichtete und unbeschichtete Bauteile. Dieses Dokument behandelt tragende Bauteile wie Wangen, Trittstufen, Setzstufen, Pfosten und Umwehrungen. Anforderungen an eine Holztreppe sind in der Produktnorm EN 15644 festgelegt. Dieses Dokument behandelt keine Treppen, die zur allgemeinen Standsicherheit von Bauwerken oder zur Festigkeit der Konstruktion beitragen.
Diese Europäische Norm gilt für den Nachweis mechanischer Leistungseigenschaften, Gebrauchstauglichkeit, Tragfähigkeit und der damit verbundenen Dauerhaftigkeit. Weitere Anforderungen, z. B. Anforderungen an bauakustische Eigenschaften, werden in dieser Europäischen Norm nicht behandelt.
Für die Konstruktion und Berechnung unter nicht ruhenden Einwirkungen sind zusätzliche Anforderungen zu berücksichtigen (zu überprüfen).
Für die Bemessung im Brandfall und bei Erdbeben/seismische Einwirkungen sind zusätzliche zu berücksichtigende Anforderungen zugelassen.
Die Verfahren in der vorliegenden Europäischen Norm gelten ohne weiteren Nachweis für verschiedene Arten von Treppenbauarten und ihre Bauteile, wie in Bild 1 dargestellt:
Escaliers en bois - Conception de la structure - Méthodes de calcul
La présente Norme Européenne constitue une norme cadre pour la conception, par des méthodes de calcul, des escaliers en bois ainsi que des éléments en bois et à base de bois utilisés dans les escaliers. Certaines méthodes de calcul peuvent être issues de résultats d’essai, par exemple la CEN/TS 15680. Le présent document spécifie la conception et les exigences relatives aux matériaux et aux éléments à utiliser dans ces méthodes de calcul. Il peut être complété par des documents d’application nationaux fondés sur la présente norme européenne.
La présente Norme Européenne s’applique aux éléments revêtus et non revêtus. Le présent document couvre les éléments porteurs tels que limons, marches, contremarches, poteaux, mains courantes et balustrades. Les exigences relatives à un escalier en bois sont définies dans la norme de produit EN 15644. Le présent document ne traite pas des escaliers qui contribuent à la stabilité générale de l’ouvrage ou à la résistance de la structure.
La présente Norme Européenne est valable pour la vérification des caractéristiques de performances mécaniques, la facilité d’usage et la capacité portante ainsi que leur durabilité associée. Les autres exigences, par exemple les exigences relatives aux propriétés acoustiques, ne sont pas traitées dans la présente norme européenne.
Pour la conception, le calcul et la détermination des actions qui ne sont pas uniquement des actions de repos, des exigences supplémentaires doivent être prises en compte (à vérifier).
Pour le dimensionnement avec une référence particulière à la résistance au feu et à l’action sismique, des exigences supplémentaires peuvent être prises en compte.
Sans vérification supplémentaire, les informations suivantes sont valables pour différents types de structures d’escaliers et leurs éléments, tels qu’illustrés dans la Figure 1 suivante :
Lesene stopnice - Dimenzioniranje konstrukcij - Računska metoda
Standard EN 16481 predstavlja okvirni standard za načrtovanje lesenih stopnic in lesenih sestavnih delov ali sestavnih delov na osnovi lesa, ki se uporabljajo v stopnicah, s pomočjo računskih metod. Nekatere računske metode je mogoče izpeljati iz preskusnih rezultatov, na primer CEN/TS 15680. Ta dokument določa načrtovanje in zahteve za materiale in sestavne dele, ki jih je treba uporabiti v teh računskih metodah. Dopolnjujejo ga lahko nacionalni izvedbeni dokumenti, ki temeljijo na tem standardu. Ta evropski standard velja za premazane in nepremazane sestavne dele. Ta dokument zajema nosilne sestavne dele, kot so notranja lica, stopnice, ličnice, sredinski drogovi, stopniščne ograje in podestne ograje. Ta dokument v delu 2 (ali dodatku, glejte poseben dokument N 283) zagotavlja primere izračunov. Zahteve za lesene stopnice določa proizvodni standard EN 15644. Ta dokument ne zajema stopnic, ki prispevajo k splošni stabilnosti konstrukcije ali trdnosti strukture. Ta evropski standard velja za verifikacijo lastnosti mehanske zmogljivosti, uporabe in nosilnosti ter z njimi povezano trajnost. Druge zahteve, npr. zahteve po akustičnih lastnostih, niso zajete v tem standardu. Za načrtovanje, izračunavanje in določanje ostalih ukrepov je treba upoštevati dodatne zahteve. (bo preverjeno naknadno). Za dimenzioniranje s posebnim poudarkom na požarni odpornosti in potresom se lahko upošteva dodatne zahteve.
General Information
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Holztreppen - Bauplanung - BerechnungsverfahrenEscaliers en bois - Conception de la structure - Méthode de calculTimber stairs - Structural design - Calculation method91.060.30Stropi. Tla. StopniceCeilings. Floors. StairsICS:Ta slovenski standard je istoveten z:EN 16481:2014SIST EN 16481:2014en,fr,de01-september-2014SIST EN 16481:2014SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16481
June 2014 ICS 91.060.30 English Version
Timber stairs - Structural design - Calculation methods
Escaliers en bois - Conception de la structure - Méthodes de calcul
Holztreppen - Bauplanung - Berechnungsmethoden This European Standard was approved by CEN on 17 April 2014.
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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
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B-1000 Brussels © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16481:2014 ESIST EN 16481:2014
a) Stair with closed string and riser SIST EN 16481:2014
b) Stair with closed string without riser
c) Stair with cut strings and riser SIST EN 16481:2014
d) Stair with cut strings without riser
e) Combination of stairs with closed string and cut string with or without riser Figure 1 — Types of stair structures and their components 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 338, Structural timber — Strength classes EN 1990, Eurocode — Basis of structural design EN 1991-1-1:2002, Eurocode 1: Actions on structures — Part 1-1: General actions — Densities, self-weight, imposed loads for buildings EN 1993-1-1, Eurocode 3: Design of steel structures — Part 1-1: General rules and rules for buildings SIST EN 16481:2014
partial safety factor for loads 3x torsional angle around the x-axis 3y torsional angle around the y-axis 3z torsional angle around the z-axis M partial safety factor for a material property 0 combination coefficient A cross-sectional area Ay cross-sectional shear area in the direction of the y-axis Az cross-sectional shear area in the direction of the z-axis Across-bracing cross-sectional area of the cross-bracing Astring calculated cross-sectional area of the string SIST EN 16481:2014
0,9 and m = 1,3. For steel parts, the assessment values XRd used within the limit state of the load-bearing capacity shall be taken from EN 1993-1-1 in the absence of relevant national directives. In the absence of relevant national directives, the characteristic stress, stiffness and bulk density indices shall be taken from EN 1995-1-1. In the absence of relevant national directives, the characteristic rupture load, Xk, is used as the lowest value derived from tests with relevance to components resistance based on three identical component tests. For rupture loads derived from components tests, and in the absence of relevant national directives, the assessment values XRd used within the limit state of the load-bearing capacity result from: 15XXX==γkkRdm, (7) Without a further national value, the default value m shall be applied as 1,5 where a minimum of 3 tests have been conducted and this value can be changed to 1,3 where 10 or more tests have been carried out (see ETAG 008). 5 Determination of mechanical stress (stress resultants and deformations) 5.1 General a) In principle, this European Standard allows the determination of mechanical stress (stress resultants and deformations) in two different ways, as follows: 1) separate determination of mechanical stress of treads or strings, respectively, with the help of structural frame analysis, either on plan or spatial, as well as static systems for all single parts independent from each other; 2) interrelated determination of mechanical stress of treads and strings with the help of spatial structural frame analysis and a spatial static system of the stair as a whole. b) The separate determination of mechanical stress is valid for: 1) all forms of single treads, 2) straight stairs with vertical support in places described in the following manner (see Figure 2),
Figure 2 — Ground plan of straight stairs SIST EN 16481:2014
Figure 3 — Ground plan of turning stairs all corners supported c) The interrelated determination of mechanical stress of steps and strings is needed for all other ground plans of stairs (see Figure 4).
Figure 4 — Ground plan of turning stairs not all corners supported d) The following calculation methods are admissible: 1) elastic bearing structure calculation; 2) plastic bearing structure calculation. e) The elastic bearing structure calculation may be used in all cases. SIST EN 16481:2014
Key dhousing depth of housing dtread thickness of the tread dstring thickness of the string hstring height of the string EA stretch stiffness of a component EIy bending stiffness around the y-axis EIz bending stiffness around the z-axis GAy rigidity stiffness in the direction of the y-axis GAz rigidity stiffness in the direction of the z-axis GIt torsional stiffness Ltread calculated span of tread wi,stair internal width of the stair wstair width of flight Figure 5 — Cross-section area of tread with closed strings and static system — The static system of a parallel tread on cut strings is that of a single-span beam with two cantilever arms (see Figure 6): SIST EN 16481:2014
Key dstring thickness of the string dtread thickness of the tread hstring height of the string Lcantilever calculated length of the overhang of a cut tread Ltread calculated span of tread wi,stair internal width of the stair wstair width of flight Figure 6 — Cross-section area of tread with cut strings and static system — The supports are taken as fork bearings and able to absorb torsional moments under eccentric load. — The calculated support span Ltread of a straight tread is the horizontal distance between the centroidal axes of the stair strings. — The cross-section of a parallel tread without riser is a rectangle. The cross-section height dtread is the thickness of the tread; the cross-section width wtread is the sum of the going and the overlap (g + o). With these measurements, the cross-section values to be applied mathematically (area, shear areas Ay and Az, torsional moment, It, and geometrical moment of inertia, Iy and Iz, respectively) are determined according to the elastic theory. — Both elasticity modulus, E, and rigidity modulus, G, shall be taken from standards, for example, EN 1995-1-1 or EN 338. Material properties may also be determined with the help of suitable tests. 5.2.2 Parallel steps with riser The span listed under 5.2.1 are also valid for parallel steps with riser. The cross-section form of a parallel step with riser may be regarded as a t-beam. Required is a friction-locked joint of the riser with the tread. Otherwise, the regulations for steps without riser apply. For the measurements of the t-beam cross-section, the mathematically applied cross-section values (area, shear area Ay and Az, respectively, torsional moment It and moment of inertia, Iy and Iz, respectively) are determined according to the elastic theory. SIST EN 16481:2014
Key 1 tread axis of the real tread 2 real ground plan of tread 3 idealized ground plan of tread dstring thickness of the string w1 outer side real tread width w1,id idealized outer side tread width w2 wall side real tread width w2,id idealized wall side tread width Figure 7 — Ground plan and idealized ground plan of tapered treads with closed strings On the basis of this idealized substitute tread, the static system of a tapered tread is modelled as follows. 2) In the case of closed strings, the static system of a tapered tread is that of a single-span beam (see Figure 8). SIST EN 16481:2014
Key 1 tread axis of the real tread 3 idealized ground plan of tread dstring thickness of the string Ltread calculated span of tread w1 outer side real tread width w1,id idealized outer side tread width w2 wall side real tread width w2,id idealized wall side tread width wav,id average value of idealized tread widths Figure 8 — Idealized ground plan of tapered treads with closed strings and static system 3) In the case of cut strings, the static system of a winding tread is that of a single-span beam with two cantilever arms. SIST EN 16481:2014
Key 1 tread axis of the real tread 3 idealized ground plan of tread dstring thickness of the string Ltread calculated span of tread w1 outer side real tread width w1,id idealized outer side tread width w2 wall side real tread width w2,id idealized wall side tread width wav,id average value of idealized tread widths Figure 9 — Idealized ground plan in case of cut strings and static system 4) The calculated span Ltread of a tapered tread of a stair is the distance of the centroidal axis of the stair strings measured in the tread axis of the idealized substitute tread. 5) The cross-section height, dtread, is the tread thickness; the cross-section width, wav,id, as the median value is derived from the values of the tread width w1,id and w2,id. With the help of these measurements, the mathematically applied cross-section values (area and moment of inertia) are determined according to the rules of the elastic theory. 6) Both elasticity and rigidity modulus shall be taken from EN 1995-1-1. SIST EN 16481:2014
Key 1 idealized support line La calculated support length at the wall side of a kite winder before the corner Lb calculated support length at the wall side of a kite winder after the corner Lc calculated support length at the outer side of a kite winder before the corner Ld calculated support length at the outer side of a kite winder after the corner Figure 10 — Ground plan showing idealized support line in case of kite winders with closed strings 2) The idealized support line of a kite winder for cut strings is centred on the centroidal axis of the strings. This is dependent on the single lengths of the support lines at the corner (see Figure 11). SIST EN 16481:2014
Key 1 idealized support line La calculated support length at the wall side of a kite winder before the corner Lb calculated support length at the wall side of a kite winder after the corner Lc calculated support length at the outer side of a kite winder before the corner Ld calculated support length at the outer side of a kite winder after the corner Figure 11 — Ground plan showing idealized support line in case of kite winders with cut strings 3) Analogously, the idealized ground plans of kite winders are determined according to the same procedure as with regard to treads (see Figure 12). SIST EN 16481:2014
Key 1 idealized support line 2 tread axis of the real tread 3 idealized ground plan of tread w1,id idealized outer side tread width w2,id idealized wall side tread width NOTE The tread axis is not in the orthogonal position to the idealized support line, but is usually the median line between the front and back edges of the idealized tread. Figure 12 — Idealized ground plan in case of kite winders with closed strings and cut strings 4) The determination of calculated span, cross-section dimensions and material properties of kite winders are carried out on the basis of the idealized ground plan of the tread according to the rules of the elastic theory. 5.3 Static systems for stair strings and their cross-sectional characteristics 5.3.1 Closed strings 1) In the case of stairs with closed strings, the static system of the stair string is that of a straight (single or multiple supported) or a turning span beam (multiple supported) with constant cross-sectional properties. In case of a straight stair, the following static system can be used, mountings are suggested as follows in Figure 13. SIST EN 16481:2014
Key 1 tread without cross-bracing 2 tread with cross-bracing 3 idealized system line of the string 4 fixture against torsional movement EA stretch stiffness of a component EIy bending stiffness around the y-axis EIz bending stiffness around the z-axis G going GAy rigidity stiffness of a component in the direction of the y-axis GAz rigidity stiffness of a component in the direction of the z-axis GIt torsional stiffness of a component Lstair length stair r rise . pitch Figure 13 — Example of static system with cross-bracing SIST EN 16481:2014
Key Dmax maximum distance between upper edge of string and upper edge of housing in section I-I Dmedium average value of Dmax and Dmin Dmin smallest distance between lower edge of string and upper edge of housing dhousing depth of housing dstring thickness of the string dtread thickness of the tread g going hhousing height of the housing hstring height of the string mlower lower margin mupper upper margin o overlap r rise . pitch Figure 14 — Cross-sectional dimensions for closed strings 5) The height of the string, hstring, is derived from the dimensions of going, g, overlap, o, step thickness, dtread, margin, mupper, margin, mlower, and pitch, ., by: SIST EN 16481:2014
Key 1 tread without cross-bracing 2 tread with cross-bracing 3 idealized system line of the string 4 fixture against torsional movement 5 rigid weightless beam EA stretch stiffness of a component EIy bending stiffness around the y-axis EIz bending stiffness around the z-axis g going GAy rigidity stiffness of a component in the direction of the y-axis GAz rigidity stiffness of a component in the direction of the z-axis GIt torsional stiffness of a component Lstair length stair r rise . pitch Figure 15 — Static system of cut string for straight stair SIST EN 16481:2014
Key 1 system line of the real cut string g going hc,string,max real maximum distance between the plumb line of a cut string to lowest edge of string hc,string,min real minimum distance between the plumb line of a cut string to lowest edge of string hcut maximum height of the cut string area hmax real maximum section height of the cut string hmin real minimum section height of the cut string hstring height of the string Lcut maximum length of the cut string area r rise . pitch Figure 16 — Elevational dimensions of the cut string 3) The minimum distance, hc,string,min of the centroidal axis of a real cut string and the lower edge of the string is: 2hh=stringc,string,min SIST EN 16481:2014
Key 1 system line of the idealized cut string dstring thickness of the string dtread thickness of the tread etread distance of the plumb line of tread and cut string H*c,string orthogonal projection of the calculated distance of the plumb line of a cut string to lowest edge of string H*string orthogonal projection of the calculated height of the cut string h*c,string calculated distance of the plumb line of a cut string to lowest edge of string h*string calculated height of the cut string Figure 17 — Cross-sectional dimensions for cut strings SIST EN 16481:2014
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