Civil Engineering Reference
In-Depth Information
steam and diesel locomotives are used. The steam impact values are signif-
icantly higher than diesel impact over most span lengths.
3.3.2 Live Loads for Highway Steel and Steel-Concrete
Composite Bridges
The live loads on highway (roadway) steel and steel-concrete composite
by the code should be used for the design of highway bridges with loaded
lengths less than 200 m. The 200 m corresponds to the maximum length
taken into account for the calibration of Load Model 1 (see
Figure 3.5
)
.
In general, the use of Load Model 1 is safe-sided for loaded lengths over
200 m. The models and associated rules are intended to cover all normally
foreseeable traffic situations (i.e., traffic conditions in either direction on any
lane due to the road traffic), which should be taken into account for design.
Specific models may be used for bridges equipped with appropriate means
including road signs intended to strictly limit the weight of any vehicle (e.g.,
for local, agricultural, or private roads). Load models for abutments and walls
adjacent to bridges are defined separately. The load models specified in EC1
derive from the road traffic models without any correction for dynamic
effects. For frame bridges, loads on road embankments may also give rise
to action effects in the bridge structure. The effects of loads on road con-
struction sites (e.g., due to scrapers and motortrucks carrying earth) or of
loads specifically for inspection and tests are not intended to be covered
by the load models and should be separately specified, where relevant.
According to EC1, loads due to the road traffic, consisting of cars, motor-
trucks, and special vehicles (e.g., for industrial transport), give rise to vertical
and horizontal and static and dynamic forces. It should be noted that the load
models defined in EC1 do not describe actual loads. They have been selected
and calibrated so that their effects (with dynamic amplification included
Key
w
Carriageway width
w
1
National lane width
1 National lane Nr. 1
2 National lane Nr. 2
3 National lane Nr. 3
4 Remaining area
4
w
1
3
w
w
1
2
w
1
1
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