vertical foundation

[Jandra11]

Hello guys, can anyone enlighten me on this type of foundation for Steel Post

1. What are the advantages/disadvantages of this foundation compare to the standard footing?

2. How do we compute for this kind of foundation? Is there any specific code or standards?

Thanks.

 

[oldestguy]

1. A "standard foundation" (footing) usually is a form of slab taking vertically imposed loads. The one shown is merely an enlarged section of a post, sometimes for convenience and, in this case, to carry overturning loads from lateral (not vertical) loads.

2. Calculations for resistance to this lateral movement involve potential for a sideways overturning movement, usually termed stability calculations. Numerous methods are out there.

 

[RickyTickyTavi]

That foundation is shallow too, which depending on soil conditions could be susceptible to movement. I know where I live, a fence post like that would probably be crooked within a few years.

 

[Jandra11]

thanks
@oldest guy. base on what you said what will be more economical and easier foundation to use in a structure like flag pole?

@ricky should I used the standard foundation and just ignore this one?

 

[oldestguy]

Since a flag post is similar to the fence post as shown,generally a foundation sized for the overturning, roughly in the shape you show is pretty standard. In this case both the most economical and easiest to build. Dimensions depend on soil type and the loads imposed.

 

[raligt]

We have generally used document PD6547:2004 to Eurocode for guidance on this. The document refers to a street light embedded foundation which also takes into account the Ground Factor G which enables the soil self weight to be added in resisting overturning as well as the s.w. of the foundation.

 

[Jandra11]

@oldestguy thank you btw this kind of foundation can be designed using IBC code 1804. I also found that the size of the footing using this method will be more economical than the standard footing.

@ralight thank you I will also check that and compare it to IBC standard