Temperature loading for beam

Hello everyone,

I am trying to estimate the thermal effect due to temperature variation for a tunnel using beam element, however we noticed that this does not depend on the soil bedding resistance: no difference in spring effort between with and without temperature load cases; while the bending moment changed quite a lot (more than what we expected for a DTZ of 21°C).

Did anyone see the same phenomenon before or is there some errors in my codes.

The model can be found below:

LTC-Thermique beam.sofistik (451.4 KB)

Thanks a lot.