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local lateral effects

dominant component action

1) These non-dominant values may be zero where the effect is favourable.

2) For a favourable effect this non-dominant value cannot be zero. A value of 0,7 is proposed in combination with dominant traction and braking action.

4) Simultaneity of two or three characteristic values, although unlikely, has been proposed as a simplification for groups 11,12,13 and 14, since no significant consequences on the design arise.

[0,8] if three or more tracks are simultaneously loaded.

6.8.3 Other representative values of the multicomponent actions

6.8.3.1 Infrequent values of the multicomponent actions

(1) The same rule as in 6.8.2(1) above is applicable by applying the factors given in Table 6.6, for each group, to the infrequent values of the relevant actions considered in each group.

Note: The relevant authority may specify otherwise.

6.8.3.2 Frequent values of the multicomponent actions

(1) The same rule as in 6.8.3.1(1) above is used, by substituting infrequent values by frequent values.

Note: The relevant authority may specify otherwise.

6.8.3.3 Quasi-permanent values of the multicomponent actions (1) Quasi-permanent traffic actions shall be taken as zero.

Note: The relevant authority may specify otheiwise

6.8.4 Traffic loads in transient situations

(1)P Traffic loads in transient design situations have to be defined by the client in agreement with the designer.

Note: Some indications are given in annex J.

6.9 Fatigue load models

(1)P A fatigue damage assessment shall be carried out for all structural elements, which are subjected to fluctuations of stress.

(2)P For normal traffic based on characteristic values of Load Model 71, including the dynamic factor <|>, the fatigue assessment shall be carried out on the basis of the traffic mixes, "usual traffic" or "traffic with 250 kN-axles", depending on whether the structure carries mixed traffic or predominantly heavy freight traffic. Details of the service trains and traffic mixes considered and the dynamic enhancement to be applied are given in annex F.

(3) Each of the mixes is based on an annual traffic tonnage of 25 x 10® tonnes passing over the bridge on each track.

(4)P For structures carrying multiple tracks, the fatigue loading shall be applied to a maximum of two tracks in the most unfavourable positions.

(5)P The fatigue damage shall be assessed over a structural life of 100 years.

(6) Alternatively, the fatigue assessment may be carried out on the basis of a special traffic mix and structural life.

Note: The special traffic mix and structural life should be specified by the relevant authority.

Models of special vehicles for road bridges

Note : The consideration of special vehicles for bridge design is intended to be limited to particular cases.

(1) The special vehicles defined here are intended to produce load effects such as are caused by vehicles which do not comply with the national regulations concerning limits of weights and, possibly, dimensions of normal vehicles.

(2) The following conventional classes of special vehicles, corresponding to usual abnormal loads, are defined in Table A.1.

Table A.1 : Classes of special vehicles

Total weight

Composition

Notation

600 kN

4 axle-lines of 150 kN

600/150

900 kN

6 axle-lines of 150 kN

900/150

1200 kN

8 axle-lines of 150 kN or 6 axle-lines of 200 kN

1200/150 1200/200

1500 kN

10 axle-lines of 150 kN or 7 axle-lines of 200 kN + 1 axle line of 100 kN

1500/150 1500/200

1800 kN

12 axle-lines of 150 kN or 9 axle-lines of 200 kN

1800/150 1800/200

2400 kN

12 axle-lines of 200 kN or 10 axle-lines of 240 kN or 6 axle-lines of 200 kN (spacing 12m) + 6 axle-lines of 200 kN

2400/200 2400/240 2400/200/200

3000 kN

15 axle-lines of 200 kN or 12 axle-lines of 240 kN +1 axle-line of 120 kN

or 8 axle-lines of 200 kN (spacing 12 m) + 7 axle-lines of 200 kN

3000/200 3000/240

3000/200/200

3600 kN

18 axle-lines of 200 kN or 15 axle-lines of 240 kN or 9 axle-lines of 200 kN (spacing 12 m) + 9 axle-lines of 200 kN

3600/200 3600/240 3600/200/200

(3) The definitions and axle arrangements are given in Table A.2, in which n gives the number of axles and the weight of each axle in each group, and e gives the axle spacing within and between each group.

(4) Vehicle widths of 3,00 m for the 150 and 200 kN axle-lines, and of 4,50 m for the 240 kN axle-lines are assumed.

Table A.2 : Description of special vehicles

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