Pylon Sign Footing Design
Pylon Sign Footing Design
(OP)
Hello Engineers,
I have been asked to design a pylon sign 6m(high) 2m(width) Supported by two metal columns (not sure yet if I beam or Tube) and closed my signs. I'm using a wind speed of 60 m/s and I try to get the reactions on the support using STAAD.Pro. During the manual computation for the design of the combined footing I get a negative reaction on bearing (The moment is too strong due to the wind and the Weight of the structure is Small). I asked some of my co-workers and they said to increase the size of the footing to get a positive bearing reactions however on site I cannot Increase the size due to some limitations. what else are the other solution for this? And another question on equation e=M/P is soil weight, footing weight is included on P?
I have been asked to design a pylon sign 6m(high) 2m(width) Supported by two metal columns (not sure yet if I beam or Tube) and closed my signs. I'm using a wind speed of 60 m/s and I try to get the reactions on the support using STAAD.Pro. During the manual computation for the design of the combined footing I get a negative reaction on bearing (The moment is too strong due to the wind and the Weight of the structure is Small). I asked some of my co-workers and they said to increase the size of the footing to get a positive bearing reactions however on site I cannot Increase the size due to some limitations. what else are the other solution for this? And another question on equation e=M/P is soil weight, footing weight is included on P?






RE: Pylon Sign Footing Design
Reaction to change doesn't stop it
RE: Pylon Sign Footing Design
Thaidavid
RE: Pylon Sign Footing Design
1) the whole thing doesn't flop over.
2) the soil isn't overstresed.
3) the footing is designed for the assumed condition.
And yes, you can include soil overburden and footing weight in P for the eccentricity calculation.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Pylon Sign Footing Design
RE: Pylon Sign Footing Design
RE: Pylon Sign Footing Design
RE: Pylon Sign Footing Design
RE: Pylon Sign Footing Design
Looks right to me:
RE: Pylon Sign Footing Design
Note that the drilled piers we are discussing are NOT piles and are comparable in price to large footings, sometimes even less expensive. As thaidavid40 notes, many electrical contractors and even general contractors can do these relatively small drilled piers. Most often, an 18 to 30 inch diameter pier, with a depth of 10 feet or less will suffice. Remember you need a 1.5 factor of safety for overturning under most US codes.
RE: Pylon Sign Footing Design
RE: Pylon Sign Footing Design
I have another question, due to lack of Dead Loads I increase the Height and depth of the footing to 1.5m H and 0.4m D and increase the dimension to 3m x 2.5m. using the method posted on my previews reply this is what I get (e=0.537m, x=2.138m, Qmax=77.785KPa) and the Factor of Safety Against overturning is 2.04. I'm just new on Designing and this is good for me but I also want to ask if this is really good to go? Sketch below
RE: Pylon Sign Footing Design