Aef is the effective contact area in compression perpendicular to the grain;
c,90,d is the design compressive strength perpendicular to the grain;
kc,90 is a factor taking into account the load configuration, the possibility of splitting and the degree of compressive deformation.
The effective contact area perpendicular to the grain, Aef, should be determined taking into account an effective contact length parallel to the grain, where the actual contact length, l, at each side is increased by 30 mm, but not more than a, or 11/2, see Figure 6.2.
(2) The value of kc,90 should be taken as 1,0 unless the conditions in the following paragraphs apply. In these cases the higher value of kc,90 specified may be taken, with a limiting value of kc,90 = 1,75.
(3) For members on continuous supports, provided that 1 ≥ 2h, see Figure 6.2a, the value of kc,90 should be taken as:
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|---|---|---|---|---|
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|
− kc,90 = 1,5 for glued laminated softwood timber
where h is the depth of the member and is contact length.
(4) For members on discrete supports, provided that 1 ≥ 2h, see Figure 6.2b, the value of kc,90 should be taken as:
− kc,90 = 1,5 for solid softwood timber
− kc,90 = 1,75 for glued laminated softwood timber provided that ≤ 400 mm
where h is the depth of the member and is contact length.
(а) (b)
Figure 6.2 – Member on (a) continuous and (b) discrete supports
DRAFTING NOTE: Paragraphs (5) to (7), figures 6.3 and 6.4 and expressions (6.5) to (6.10) are void.
6.1.7 Shear
Delete paragraphs (1)P and (2) and replace with
(1)P For shear with a stress component parallel to the grain, see Figure 6.5(a), as well as for shear with both stress components perpendicular to the grain, see Figure 6.5(b), the following expression shall be satisfied
(6.13)
where:
τd is the design shear stress;
fv,d is the design shear strength for the actual condition.
NOTE: The shear strength for rolling shear is approximately equal to twice the tensile strength perpendicular to grain.
(2) For the verification of shear resistance of members in bending, the influence of cracks should be taken into account using an effective width of the member given as:
(6.13a)
NOTE: The recommended value for kcr is given as
kcr = 0,67 for solid timber
kcr = 0,67 for glued laminated timber
kcr = 1,0 for other wood-based products in accordance with EN 13986 and EN 14374.
Information on the National choice may be found in the National annex.
Figure 6.5 – (a) Member with a shear stress component parallel to the grain (b) Member with both stress components perpendicular to the grain (rolling shear)
(3) At supports, the contribution to the total shear force of a concentrated load F acting on the top side of the beam and within a distance h or hef from the edge of the support may be disregarded (see Figure 6.6). For beams with a notch at the support this reduction in the shear force applies only when the notch is on the opposite side to the support.
Figure 6.6 – Conditions at a support, for which the concentrated force F may be disregarded in the calculation of the shear force
6.3.3 Beams subjected to either bending or combined bending and compression
Paragraph (6), modify to read as follows:
(6) In the case where a combination of moment My about the strong axis y and compressive force Nc exists, the stresses should satisfy the following expression:
(6.35)
where:
σm,d is the design bending stress;
σc,0,d is the design compressive stress parallel to grain;
fc,0,d is the design compressive strength parallel to grain;
kc,z is given by expression (6.26).
6.4.3 Double tapered, curved and pitched cambered beams
Paragraph (7), delete
For combined tension perpendicular to grain and shear the following expression shall be satisfied:
and replace with the following:
For combined tension perpendicular to grain and shear the following expression should be satisfied:
8.1.3 Multiple shear plane connections
Paragraph (2), modify to read as follows:
To be able to combine the resistance from individual shear planes in a multiple shear plane connection, the governing failure mode of the fasteners in the respective shear planes should be compatible with each other and should not consist of a combination of failure modes (a), (b), (g) and (h) from Figure 8.2 or modes (c), (f) and (j/l) from Figure 8.3 with the other failure modes.
8.2.3 Steel-to-timber connections
Paragraph (3), expression (8.10), modify to read as follows:
(c)
(d) (8.10)
(e)
8.3.1 Laterally loaded nails
8.3.1.1 General
Delete paragraph (2) and replace with:
(2) Timber should be pre-drilled when:
− the characteristic density of the timber is greater than 500 kg/m³;
− the diameter d of the nail exceeds 6 mm.
8.3.2 Axially loaded nails
Paragraph (1)P, delete and replace with:
(1)P Nails used to resist permanent or long-term axial loading shall be threaded.
NOTE: The following definition of threaded nails is given in EN 14592: Nail that has its shank profiled or deformed over a part of its length of minimum 4,5 d (4,5 times the nominal diameter) and that has a characteristic withdrawal parameter fax,k greater than or equal to 6 N/mm2 when measured on timber with a characteristic density of 350 kg/m3 when conditioned to constant mass at 20 ºC and 65 % relative humidity.
Paragraph (10), delete and replace with:
(10) For slant nailing the distance to the loaded end should be at least 10d (see Figure 8.8(b)). There should be at least two slant nails in a connection.
8.5.1.1 General and bolted timber-to-timber connections
Table 8.4, third column, fifth row, delete
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4 d |
and replace with:
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4 d |
8.4 Stapled connections
Paragraph (1), modify to read as follows:
The rules given in 8.3, except for 8.3.1.1(4) and (6) and 8.3.1.2(7), apply for round or nearly round or rectangular staples with bevelled or symmetrical pointed legs.
8.7.2 Axially loaded screws
Delete paragraphs (1) to (7) and replace with
(1)P For the verification of resistance of axially loaded screws, the following failure modes shall be taken into account:
− the withdrawal failure of the threaded part of the screw;
− the tear-off failure of the screw head of screws used in combination with steel plates, the tear-off resistance of the screw head should be greater than the tensile strength of the screw;
− the pull-through failure of the screw head;
− the tensile failure of the screw;
− the buckling failure of the screw when loaded in compression;
− failure along the circumference of a group of screws used in conjunction with steel plates (block shear or plug shear);
(2) Minimum spacings and end and edge distances for axially loaded screws, see figure 8.11a, should be taken from Table 8.6, provided the timber thickness t ≥ 12d.
Table 8.6 – Minimum spacings and end and edge distances for axially loaded screws
|
Minimum screw spacing in a plane parallel to the grain a1 |
Minimum screw spacing perpendicular to a plane parallel to the grain a2 |
Minimum end distance of the centre of gravity of the threaded part of the screw in the member a1,CG |
Minimum edge distance of the centre of gravity of the threaded part of the screw in the member a2,CG |
|
7d |
5d |
10d |
4d |
Key: 1 Centre of gravity of the threaded part of the screw in the member
Figure 8.11.a – Spacings and end and edge distances
(3) The minimum point side penetration length of the threaded part should be 6d.
(4) For connections with screws in accordance with EN 14592 with
− 6 mm ≤ d ≤ 12 mm
− 0,6 ≤ d1/d ≤ 0,75
where
d is the outer thread diameter
d1 is the inner thread diameter
the characteristic withdrawal capacity should be taken as:
(8.38)
where:
(8.39)
(8.40)
Fax,α,Rk is the characteristic withdrawal capacity of the connection at an angle α to the grain, in N;
fax,k is the characteristic withdrawal strength perpendicular to the grain, in N/mm2;
nef is the effective number of screws, see 8.7.2(8);
ef is the penetration length of the threaded part, in mm;
ρk is the characteristic density, in kg/m3;
α is the angle between the screw axis and the grain direction, with α ≥ 30°.
NOTE: Failure modes in the steel or in the timber around the screw are brittle, i.e. with small ultimate deformation and therefore have a limited possibility for stress redistribution.
(5) Where the requirements with respect to the outer and inner thread diameter given in (4) are not satisfied, the characteristic withdrawal capacity, Fax,α,Rk , should be taken as:
(8.40a)
where
fax,k is the characteristic withdrawal parameter perpendicular to the grain determined in accordance with EN 14592 for the associated density ρa;
ρa is the associated density for fax,k, in kg/m3
and the other symbols are explained in (4).
(6) The characteristic pull-through resistance of connections with axially loaded screws should be taken as:
(8.40b)
where:
Fax,α,Rk is the characteristic pull-through capacity of the connection at an angle α to the grain in N, with
α ≥ 30°;
fhead,k is the characteristic pull-through parameter of the screw determined in accordance with EN 14592for the associated density ρa;
dh is the diameter of the screw head in mm and the other symbols are explained in (4).
(7) The characteristic tensile resistance of the connection (head tear-off or tensile capacity of shank), Ft,Rk , should be taken as:
(8.40c)
where
ftens,k is the characteristic tensile capacity of the screw determined in accordance with EN 14592;
nef is the effective number of screws, see 8.7.2(8).
(8) For a connection with a group of screws loaded by a force component parallel to the shank, the effective number of screws is given by:
nef = n0,9 (8.41)
where:
nef is the effective number of screws;
n is the number of screws acting together in a connection.
8.8.5.2 Plate capacity
Paragraph (2), modify expression (8.58) to read as follows:
for Fx,Ed> 0 (8.58)
For Fx,Ed≤ 0
8.10 Toothed-plate connectors
Paragraph (2), modify expression (8.72) to read as follows:
for tyhes C1 to C9 (8.72)
for tyhes С10 to С11.
Paragraph (4), delete
he is the tooth penetration depth, in mm.
and replace with the following:
he is the tooth penetration depth
9.2.4.2 Simplified analysis of wall diaphragms – Method A
Paragraph (3), delete
where Fi,v,Rd is the design racking load-carrying capacity of the wall panel in accordance with 9.2.4.2(3) and 9.2.4.2(5)
and replace with the following:
where Fi,v,Rd is the design racking load-carrying capacity of the wall panel in accordance with 9.2.4.2(4) and 9.2.4.2(5).
9.2.4.3.2 Design procedure
Paragraph (3), delete
s0 is the basic fastener spacing, see (4) below;
kd is the dimension factor for the panel, see (4) below;
and replace with:
s0 is the basic fastener spacing, in m, see (4) below;
kd is the dimension factor for the wall, see (4) below;
Paragraph (4), delete
- (9.26)
where:
d is the fastener diameter, in mm;
ρk is the characteristic density of the timber frame;
and replace with:
- (9.26)
where:
s0 is the basic fastener spacing, in m;
d is the fastener diameter, in mm;
ρk is the characteristic density of the timber frame, in kg/m3;
10.4.5 Screws
(1) For pre-drilling screws in softwoods with a smooth shank diameter d ≤ 6 mm, pre-drilling is not required. For all screws in hardwoods and for pre-drilling screws in softwoods with a diameter d > 6 mm, pre-drilling is required, with the following requirements:
− The lead hole for the shank should have the same diameter as the shank and the same depth as the length of the shank
− The lead hole for the threaded portion should have a diameter of approximately 70 % of the shank diameter.
(2) For timber densities greater than 500 kg/m3, the pre-drilling diameter should be determined by tests.
(3)P Where pre-drilling is applied to selfdrilling screws, the lead hole diameter shall not be greater than the inner thread diameter d1.
Annex A (Informative): Block shear and plug shear failure at multiple dowel-type steel-to-timber connections
Paragraph (1), modify expressions (A.3) and (A.7) to read as follows:
failure modes (c,f,j/l,k,m) (A.3)
all other failure modes
(e)(h) (A.7)
(d)(g)
C.3.1 Assumptions
Paragraph (2), modify fifth indent to read as follows:
− the joints, packs and gussets are designed in accordance with C.3.3;
C.3.2 Axial load-carrying capacity
Paragraph (1), modify to read as follows:
(1) For column deflection in the y-direction (see Figure C.1) the load-carrying capacity should be taken as the sum of the load-carrying capacities of the individual members.
Європейський стандарт EN 1995-1-1:2004/А1
Червень 2008
ICS 91.010.30; 91.080.20
Англомовний варіант
Єврокод 5: Проектування дерев’яних конструкцій – Частина 1-1: Загальні відомості – Загальні правила та правила для будинків
Ця поправка А1 вносить зміни до Європейського стандарту EN 1995-1-1:2004; вона була прийнята СЕN (Європейським комітетом зі стандартизації) 10 квітня 2008 року.
Члени СЕN зобов’язані дотримуватися Внутрішнього Регламенту СЕN/СЕNЕLЕС (Європейського комітету зі стандартизації / Гармонізованої системи оцінки якості електронних виробів), який визначає умови включення цієї поправки до відповідного національного стандарту без будь-яких змін. Оновлені списки і бібліографічні посилання на такі національні стандарти можна отримати, звернувшись із заявою до Адміністративного Центру СЕN або до будь-якого члена СЕN.
Ця поправка існує у трьох офіційних варіантах (англійською, французькою, німецькою мовами). Варіант будь-якою іншою мовою, перекладений під відповідальність члена СЕN на його власну мову і зареєстрований в Адміністративному Центрі СЕN, має такий самий статус, що й офіційні варіанти.
Членами СЕN є національні органи стандартизації Австрії, Бельгії, Болгарії, Кіпру, Чеської Республіки, Данії, Естонії, Фінляндії, Франції, Німеччини, Греції, Угорщини, Ісландії, Ірландії, Італії, Латвії, Литви, Люксембургу, Мальти, Нідерландів, Норвегії, Польщі, Португалії, Румунії, Словаччини, Словенії, Іспанії, Швеції, Швейцарії та Об’єднаного Королівства.
Передмова
Цей документ (EN 1995-1-1:2004/A1:2008) був підготований Технічним комітетом СEN/ТС 250 “Будівельні Європейські стандарти”, секретаріат якого знаходиться у BSI (Британський інститут стандартів).
Ця поправка до Європейського стандарту EN 1995-1-1:2004 повинна отримати статус національного стандарту шляхом або публікації ідентичного тексту, або підтвердження чинності цього тексту не пізніше грудня 2008 року, а національні стандарти, які йому суперечать, повинні бути вилучені не пізніше березня 2010 року.
