Modelling a Bridge with solid-shaft

[X-Wing]

Hi, what is the correct way of modelling (specifically in staad) a 2-span bridge wherein the middle pier consist of solid shaft to spread footing foundation?

 

[BAretired]

What do you know about the soil?

BA

 

[X-Wing]

^Hi BAretired, I'm not directly involved in the project, but we can assume that the soil is relatively hard that's why they opt to use spread footing, the bridge is just a widening on the left side, and there is an existing right side widened on spread footing. Thanks!

 

[BAretired]

You could model the base of the pier as fixed, but that would not be precise. Better to model it as a rotational spring whose spring constant is dependent on footing stiffness and soil properties.

BA