foundations for guyed and self-supporting towers 4

[buns1]

I am looking for examples or information on the design of foundations for guyed towers and self supporters including pad and pier and also caisson design for base and anchor design. Any information on books, examples, ect. would be great help.

thanks
matt

 

[Focht3]

Matt -

I've designed quite a few guyed and self-supports from a foundation perspective; there isn't a cookbook design for them (although Rohn gets close with their "standard" designs.) Find a qualified local geotechnical engineer with tower experience (guyed, self support & monopole) - and don't go for the cheapest guy, either (no pun intended.) You're buying experience, not test results.

While concrete and steel are expensive, they are cheap compared to sites where you can't economically install the designed foundation, or the foundation is inadequate. You discover one during construction; the other appears when the tower falls. And your question indicates that you are unlikely to know the 'problem' sites.

Save yourself the headache - hire an expert.

 

[scofie]

You may wish to purchase the IEEE Standard 691, "IEEE Guide for Transmission Structure Foundation Design and Testing," published 26 December 2001. I have found it a helpful resource. As mentioned by Focht3, you can also review the Rohn catalog for tabular sizing of tower foundations, although these tables were developed in the early 1970's and only for "normal" soils, so their use is only as a starting point.

There is an ASCE Geotechnical Special Publication No. 8, "Foundations for Transmission Line Towers", but I found this collection of conference papers of limited use in my practice.

Lastly, you will want to comply with the foundation requirements in the ANSI/TIA/EIA-222-F, "Structural Standards for Steel Antenna Towers and Antenna Supporting Structures." The current version F has a few requirements for foundation design, such as size and factor of safety criteria. The next version, G, due out next summer will be adding even more requirements for foundations and other tower components.

Good luck to you.