STANDARDS @ SILOS and cylindrical shells

[freddy]

Recently I have been designing silos according to DIN 1055, DIN 4119, DIN 18914 and ECCS recommendations: I would like to exchange opinions with somebody using different standards about calculating wind effects on shells and how to consider ring stiffenings in buckling behaviour.

 

[paulomanuel]

Unlike regular and normal structures, especial structures demand a lot more from you, for not everything comes in codes and standards. Some things come with experience and are not scientifically tested.
You have to make some adaptations and create your own models. It is not always possible to apply codes because they are made for some ideal situations like most buckling verifications.
Try to know what you are doing and be reasonable.
Good luck.

 

[ADT]

Freddy I think you'd be better off getting hold of some detailed technical papers on this subject. I suggest the professional engineering bodies in US, Australia, UK who all publish their member's submissions and assist members to search for such information.

While I haven't designed a silo for a long time I would recommend you pay very close attention to the effect of eccentricity and of impact during storage/unloading of the material within. Arching of the material itself, whether grain or cement etc can also produce sudden internal impact during loading or unloading.

Wind effects will be important for an unloaded/empty/part empty concrete shell silo. Whether they would govern the design I'm doubtful, except in cyclonic and very high-wind areas. If the slenderness is large you might also have to look at eddy-shedding which will produce oscillating wind forces.

It's a complex topic. I would be doing a whole lot of reading and then practice, practice.

Anthony Tugwell
Project Director & Consulting Engineer - currently in Kuala Lumpur. Malaysia

 

[eureka]

freddy, I agree with ADT. Reading technical papers and researching some of their references is the way to go. A good starting place for the US is the American Society of Civil Engineers. Log on to

http://www.asce.org,

then go to Publications, then go to CE Database. Do a search on 'silos' You will find numerious papers on various aspects of designing silos. Good luck.