THERMAL-STRESSES IN COMPOSITE BRIDGES ACCORDING TO BS-5400 AND EC-1

Design engineers evaluate accurately dead and live loads acting on bri dges, However, in the case of thermal loads, the bridge designer bases the assessment of these loads on his experience and on codes of pract ice, In this paper the stress effects of the temperature distributions recommended in BS 5400 (1978) and EC 1 (1995) are determined for a bo x girder and a double plate composite bridge deck, These are compared with the stress effects corresponding to temperature distributions obt ained from theoretical two-dimensional time-dependent thermal and stru ctural analysis of composite bridges, The study shows that the design temperature distribution recommended in BS 5400 represents the phenome non of heat transfer in composite bridges realistically, The linear te mperature distribution recommended in EC 1, however, does not allow su ch a precise representation of the actual stress effects of the temper ature field in composite bridges, The significance of inaccuracies in the calculation of thermal stress effects is also discussed.