Separate Spread Foundation Design https://members.theihe.org/forums/posts.aspx?group=214541&topic=1485805 Sun, 7 Jun 2026 22:57:14 GMT Wed, 1 May 2019 12:33:53 GMT Copyright © 2019 Institute of Highway Engineers Separate Spread Foundation Design https://members.theihe.org/forums/posts.aspx?group=214541&topic=1485805 https://members.theihe.org/forums/posts.aspx?group=214541&topic=1485805
tony_ruddy 
I am in need of help again!! I am trying to design separate spread foundations for a large sign (3 spread foundations, 1 for each post). I have been following the guidance using the Sign Structures Guide 2010 and Eurocodes but I am unsure whether to carry out the calculation for 1 sign foundation and combine them. Can anyone point me in the right direction? Thanks again.
]]> Wed, 1 May 2019 13:33:37 GMT https://members.theihe.org/forums/posts.aspx?group=214541&topic=1485806 https://members.theihe.org/forums/posts.aspx?group=214541&topic=1485806 September 2015

Provided the posts are positioned symmetrically and the ground is level, you could just divide the wind load by 3 and design each separate foundation for that.
In theory the middle post is subjected to a greater load, but in practice it is usually convenient to make the 3 separate bases all the same size, on the assumption that the sign structure will deflect slightly under extreme loading to redistribute the load in an efficient way. Each separate base should be designed to support the whole of the point load that could be applied to any point on the sign.]]> Wed, 1 May 2019 13:33:53 GMT