Ultimate limit state of static equilibrium

(1) For design situations during which there is a risk of loss of static equilibrium, the following combination of actions should be considered :

Z^d,supM+MZGd,mf M+"Yp^n+MyQl Gda.lk^Evoi YQiGdsUk (B.l)

(2dst,lk IS characteristic value of the dominant destabilizing variable action; £?dst,ik is ^e characteristic value of the accompanying destabilizing variable actions.

Note : P is a characteristic or a mean value depending, at the present time, on the project specification. Very varied situations may have to be considered during the execution of a bridge, for which formula (B. 1) needs possibly amendments (e.g. for the verification of stabilization stays).

(2) For self-weight of structural and non-structural elements, see 4.1.3.

(3) In general, where a counterweight is used, the variability of the action due to its self-weight should be considered. Unless otherwise specified, this variability should be taken into account by any of the following alternatives:

- applying a partial factor Ycinf = where the self-weight is not well defined (e.g. containers);

- by considering a variation of its project-defined location, with a value to be specified proportionately to the dimensions of the bridge, where the magnitude of the counterweight is well defined.

Note : For steel bridges during launching, the variation of the counterweight location is often taken equal to ± 1 m.

(4) Unless otherwise specified, the y factors for all variable loads should be taken equal to [1,35] and yP = [1,0].

(5) The values of i|/0 factors are given in Table B. 1 (see B.2).

(6) Where loss of static equilibrium is prevented by stabilizing systems or devices (e.g. stays, auxiliary columns), their resistance and/or their stability should be checked in accordance with the rules defined in the relevant design Eurocodes.

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