100' Super Column at Golf Driving Range 3

Design your poles per Std. Specs for Structural Supports for Hiway Signs,..... per ASSHTO.

Just develop your loads; ie. net weight, pretrensioning of cables, some sort of wind on the netting and full wind on the poles themselves. Use your local area wind criteria.

Develop some pole deflection criteria. I once did a series of poles embedded in a earth dam being constructed. Just the electric lines between the poles pulled the end poles over a foot or so. (The poles supported a light bank for the earth moving equipment that worked 24/6.)

100 foot poles are pretty common. We've designed free standing flag poles over 400 feet.

There are a few companies that specialize in fabricating the poles. They will also design the poles and foundations. If you go this route (performance spec), ask for the design to be submitted for approval and review the foundation design thoroughly, as we disagreed with the submitted design.

Our job is 3 years old and the netting is failing in two ways. The contractor (and inspector) did not understand the importance of installing the steel cables correctly. They are snapping due to fatigue at the supports. Also, the nets were manufactured poorly , and the attachment to the perimeter cables is failing due to abrasion.

Is it feasible or economical to use "precast" columns?

Do you have to design the cabling and the fittings?

One way to account for wind pressure on the netting is to look at the similarities of netting and chain link fencing. The Chain Link Fence Manufacturers Institute offers this guide
Most of it does not apply to your situation, but the assumptions on pages numbered 3 and 4 could be considered. The calculations are a little old, based on the 1995 edition of ASCE 7.

I go by a driving range everyday. I cannot believe they have not thrown in the towel. Every winter it is virtually destroyed by ice build up tearing down the nets. Then there is the above mentioned abrasion problem. And enough balls go through the netting that you have to sign a release to personally cover damage to passing cars.

Mike

As we found out, a warranty is useless if the netting manufacturer declares bankruptcy.

Ask the netting supplier to design for ice load, unless the owner agrees to remove the nets in the winter. Also, design for wind on ice. We didn't find any code which specified the wind load, so we made up our own. We called for 2 load cases; 80 mph wind on 12% solid area, and 40 mph on 90% solid area, with ice load. The second case governed.

Thank you everyone. We have decided to take the performace spec route. THanks for the great info. above.
Brian