Table NA.A2.1 - Recommended values of ψ factors for road bridges
Action
Groups of Loads
Load components
ψ0
ψ1
ψ2
Traffic Loads
gr1aa
TS
0,75
0,75
0
UDL
0,75
0,75
0
Footway and cycle-track loads
0,40
0,40
0
gr1ba
Single axle
0
0,75
0
gr2
Horizontal forces
0
0
0
gr3
Pedestrian loads
0
0,4
0
gr4
Crowd loading
0
_b
0
gr5
Vertical forces from SV and SOV vehicles
0
_b
0
gr6
Horizontal forces from SV and SOV vehicles
0
0
0
Wind forces
FWk
Persistent design situations
0,50
0,20
0
During execution
0,80
_
0
F*W
During execution
1,0
_
0
Thermal actions
Tk
0,60
0,60
0,50
Snow loads
QSn,k
0,80
_
_
Construction Lds
Qc
1,0
1,0
a The recommended values of ψ0, ψ1, ψ2 for gr1a and gr1b are given for roads with traffic corresponding to adjusting factors αQi, αqi, αqr and βQ defined in the NA to BS EN 1991-2:2003.
b The frequent values of load groups gr4 and gr5 do not need to be considered in accordance with BS EN 1991-2:2003, 4.5.2
NOTE The ψ0 factors specified for a group of loads apply to all the component actions in that group, except for gr1a where they are individually specified. The ψ1, ψ2, factors always apply to individual components of loading and the values for a given component are the same in all load groups in which the component occurs.
Table NA.A2.2 - Recommended values of ψ factors for footbridges
Action
Symbol
ψ0
ψ1
ψ2
Traffic loads
gr1
0,40
0,40
0
Qfwk
0
0
0
gr2
0
0
0
Wind forces
FWk
0,30
0,20
0
Thermal actions
Tk
0,60
0,60
0,50
Snow loads
Qsn,k (during execution)
0,80
_
0
Construction Lds
Qc
1,0
_
1,0
Traffic Loads: gr1a
ψ0
ψ1
ψ2
TS
0,75
0,75
0
UDL
0,75
0,75
0
Footway and cycle-track loads
0,40
0,40
0
Traffic Loads: gr1b
ψ0
ψ1
ψ2
Single axle
0
0,75
0
The recommended values of ψ0, ψ1, ψ2 for gr1a and gr1b are given for roads with traffic corresponding to adjusting factors αQi, αqi, αqr and βQ defined in the NA to BS EN 1991-2:2003.
Traffic Loads: gr2
ψ0
ψ1
ψ2
Horizontal forces
0
0
0
Traffic Loads: gr3
ψ0
ψ1
ψ2
Pedestrian loads
0
0,4
0
Traffic Loads: gr4
ψ0
ψ1
ψ2
Crowd loading
0
_b
0
Traffic Loads: gr5
ψ0
ψ1
ψ2
Vertical forces from SV and SOV vehicles
0
_b
0
b:
The frequent values of load groups gr4 and gr5 do not need to be considered in accordance with BS EN 1991-2:2003, 4.5.2
Traffic Loads: gr6
ψ0
ψ1
ψ2
Horizontal forces from SV and SOV vehicles
0
0
0
Wind forces FWk
ψ0
ψ1
ψ2
Persistent design situations
0,50
0,20
0
During execution
0,80
_
0
Wind forces F*W
ψ0
ψ1
ψ2
During execution
1,0
_
0
Thermal actions
ψ0
ψ1
ψ2
Tk
0,60
0,60
0,50
Snow loads
ψ0
ψ1
ψ2
QSn,k
0,80
_
_
Construction Lds
ψ0
ψ1
ψ2
Qc
1,0
1,0
NOTE The ψ0 factors specified for a group of loads apply to all the component actions in that group, except for gr1a where they are individually specified. The ψ1, ψ2, factors always apply to individual components of loading and the values for a given component are the same in all load groups in which the component occurs.
Table NA.A2.2 - Recommended values of ψ factors for footbridges
Traffic loads
ψ0
ψ1
ψ2
gr1
0,40
0,40
0
Qfwk
0
0
0
gr2
0
0
0
Wind forces
ψ0
ψ1
ψ2
FWk
0,30
0,20
0
Thermal actions
ψ0
ψ1
ψ2
Tk
0,60
0,60
0,50
Snow loads
ψ0
ψ1
ψ2
Qsn,k (during execution)
0,80
_
0
Construction Lds
ψ0
ψ1
ψ2
Qc
1,0
_
1,0
Contact David Childs
David Childs
B.Sc, C.Eng, MICE
Last Updated: 28/01/2020