Civil Engineering Reference
In-Depth Information
Material
Standard
Service
class
Load duration class
Permanent
action
Long term
action
Medium term
action
Short term
action
Instantaneous
action
Solid timber
EN 14081-1
1
2
3
0.60
0.60
0.50
0.70
0.70
0.55
0.80
0.80
0.65
0.90
0.90
0.70
1.10
1.10
0.90
Glued laminated
timber
EN 14080
1
2
3
0.60
0.60
0.50
0.70
0.70
0.55
0.80
0.80
0.65
0.90
0.90
0.70
1.10
1.10
0.90
LVL
EN 14374, EN 14279
1
2
3
0.60
0.60
0.50
0.70
0.70
0.55
0.80
0.80
0.65
0.90
0.90
0.70
1.10
1.10
0.90
Plywood
EN 636
Part 1, Part 2, Part 3
Part 2, Part 3
Part 3
1
2
3
0.60
0.60
0.50
0.70
0.70
0.55
0.80
0.80
0.65
0.90
0.90
0.70
1.10
1.10
0.90
OSB
EN 300
OSB/2
OSB/3, OSB/4
OSB/3, OSB/4
1
1
2
0.30
0.40
0.30
0.45
0.50
0.40
0.65
0.70
0.55
0.85
0.90
0.70
1.10
1.10
0.90
Particle-board
EN 312
Part 4, Part 5
Part 5
Part 6, Part 7
Part 7
1
2
1
2
0.30
0.20
0.40
0.30
0.45
0.30
0.50
0.40
0.65
0.45
0.70
0.55
0.85
0.60
0.90
0.70
1.10
0.80
1.10
0.90
Fibreboard, hard
EN 622-2
HB.LA, H8.HLA 1 or 2
HB.HLA 1 or 2
1
2
0.30
0.20
0.45
0.30
0.65
0.45
0.85
0.60
1.10
0.80
Fibreboard,
medium
EN 622-3
MBH.LA 1 or 2
MBH.HLS 1 or 2
MBH.HLS 1 or 2
1
1
2
0.20
0.20
-
0.40
0.40
-
0.60
0.60
-
0.80
0.80
0.45
1.10
1.10
0.80
Fibreboard, MDF
EN 622-5
MDF.LA, MDF.HLS
MDF.HLS
1
2
0.20
-
0.40
-
0.60
-
0.80
0.45
1.10
0.80
Table 19.9 Values of k
mod
(BSI, 2004). Permission to reproduce extracts from BS EN 1995-1-1 is granted by BSI
Note that the index
s
may be taken as 0.12 but should be
checked against manufacturer's information
k
sys
is a load sharing factor normally 1.1 for spacing of
members ≤ 610 mm centres where there is distribution of the
applied loading by tiling battens, roof or floor decking across a
number of members; a relaxation is given allowing spacings to
be increased to 1200 mm dependent upon the stiffness of the
load distributing elements.
Modification factors for structural effects such as instability
are given in the following.
19.5.2 Member axes
The axes in all Eurocodes are expressed in the same manner as
in a 3D computer analysis as shown in
Figure 19.8
, where the
z axis is the minor axis.
19.5.3 Bending
The actual bending stress must be less than or equal to the
design strength (
Figure 19.9
). Taking a simple beam bending
about its major axis,
