How to calculate dynamic earth pressure around a circular tunnel?

Question

Faseel Khan · Answer

Thank you for your post. As this addresses a question to the whole geotechnical community, I leave it open to our fellow geotechnical engineers to comment based on their experience.

Stefanos Papavasileiou · Answer

Dear Manisha, 
 In general, you should check the results on the added interfaces around the tunnel as they provide direct results. 
 Note that PLAXIS even in a dynamic analysis, does not separate between static and dynamic as it simply calculates the "total" effect of the stresses due to the applied conditions. 
 Check this relevant forum post, too: RE: Seismic Ovalization Analysis of Tunnel Permanent Linings

Stefanos Papavasileiou · Answer

Hello Manisha, 
 A pre-calc curve point on an interface will return the soil stress point, as pre-calc points do not support selection on structures and interfaces are considered as such. 
 You can, however, save all calculation steps, select a post-calc curve point and then select an interface stress point to retrieve the results. 
 This will give you the full history of the interface stress point which can reveal the changes in normal stresses during the dynamic event.

Stefanos Papavasileiou · Answer

Hello again, 
 I am not sure what's your definition of dynamic earth pressure, but I have explained above that via a curve point on the interface you will get the full history (path) of the normal stress during your calculation. 
 This can be a dynamic analysis (seismic, vibration, etc.) or a consolidation or any time-dependent analysis. 
 The outcome is a plot that shows you the changes of that result on that curve point during the analysis.