thermal movement of curved girder bridges with 2 fixed piers

[KLMPE]

thread507-220723
For curved girder bridges that have 2 adjacent fixed piers which are relatively rigid in the superstructure transverse direction, would the point of fixity for determining the expansion chord (design of bearings), be at the closest fixed pier, or midway between the 2 fixed piers? Has anyone seen any substantiated guidance on this?

 

[ishvaaag]

Quite likely the best answer is that if the model holds both superstructure and substructure, the point of fixity would be at the foundations, and everything subject to the proper thermal loading sets assumed.

If separate, as it seems to be your intent, again, the best way would be to proceed in akin way, that is, you establisn at the supports at the piles the fixities you have, then apply the thermal loadings, and let relax the model, or models in their different status of construction, to equilibrium for the required loadcases. So you don't need in any case other point of fixity than the supports themselves, even if instead of fixed longitudinally and transversally are able to show some displacement or just partial stiffness instead of complete amobility.