Tangential dynamic ground motion

[fast98]

Hello Silvia,

Do you know how to apply seismic loadings to curved bridge? I mean curved bridge consists of the different radius at each pier or abutment so that longitudinal loading direction would be tagent line to the orientation of abutments

And, if the longitudinal dynamic ground motion is applied to curved bridge, the longitudinal seismic loading should be along with the tangent line to the curve at that points(e.g., piers, etc.). Could you please inform me how I am able to apply tangent loadings to curved bridge?


Thanks,
Patrick

[silvia]

interesting problem, i have never done it.
first of all, you need to use the multiple-support excitation type of loading, where you specify displacement histories specified nodes (easy).
right now, you can specify the displacements in each of the global coordinates. you can break down the tangential displacement into the two coordinates, otherwise you can use a truss parallel to the direction you want, and specify the displacements at the other end of the truss...

these are just a few ideas, let us know how it goes.