Shaking All Over
I sympathise with you on this one.
Firstly: the bin moves towards the material. Then the surcharge shifts into (not in) the direction of the seismic acceleration. There is a previous similar thread for your search reference. I would think that the floor level shear should be subtracted from the seismic loading as you suggest.
Unfortunately the local design codes must still be applied. Those codes are the legal requiirement however excessive they might seem. 'AS 3774 - Loads on Bulk Solids Containers' might be helpful. ■
Absence Of Official Squat Silo Literature
These local design codes push silo design for earth quake resistance in the wrong direction.
Is there any official non code literature which covers the subject? ■
Rocky Xxx
Think about it: if it is non code then it cannot be official.
Designer (Saisons Greetings ould mon,) once referred to the Irishism , "If I wanted to get there: I wouldn't be starting from here."
DEM would be a classic application for your studies: and quite cost effective. ■
Way Out
Some design codes rule like that: ... standard not intended to direct designer to use only those equations .. provided. Should designer wish to carry out a detailed analysis OF ANY ASPECT of ...., the results of such analysis MAY BE SUBSTITUTED FOR THE CORRESPONDING REQUIREMENT OF THE STANDARD.
If you find that somewhere IN THE RESPECTIVE design rule, its the way out as proposed by louispanjang. If not, it must be done by design rule requirement. Last chance: Talk to the customer, if it's a no-go, even if that hurts.
Don't try to swerve, that would be unprofessional. The most difficult situation imaginable: when a problem like that surfaces after the priced offer was made.
However it turns out: Good luck!
R. ■
Earth Quake Design for Large Squat Silos
Dear forum people,
rigourus earth quake design by norm results in taking around 80% of the silo contents and use this as distributed weight in the equivalent lateral force procedure.
The normal structure weight has to be included also.
For small silos, this is not a real problem.
When the storage capacity becomes 30.000 m^3 (For example : D = 40 m , Storage height = 24 m) , these calculations become problematic.
It is also not very realistic to account 80% of the storage content towards the silo wall, since the ground surface for the content is relatively large.
Is there any official literature, which takes such considerations into account? ■