Tower Foundation on weak soils
Tower Foundation on weak soils
(OP)
An unguided 20 meter tower is to be erected on high water table soils with high organics. The tower is for a privately owned ham radio. The manufacture provided a foundation 100 mph design for dry soils min 2500 psf.
The 3 sec peak in our are is 120 mph.
What is the high water, organic soils foundation design impact? Any links?
The 3 sec peak in our are is 120 mph.
What is the high water, organic soils foundation design impact? Any links?





RE: Tower Foundation on weak soils
RE: Tower Foundation on weak soils
I would be very concerned about the overturning moment due to wind loading especially with the high water table conditions. Drive a stake into dry ground, push it over. Drive the same stake into the same ground and add water. Push it over. See the difference?
MikeDB's comments refer to the ability of the soil to resist vertical load, resistance to overturning will be less because the soil can move out of the way of the rotating foundation.
I would get the specific advice of a geo-technical engineer familiar with the area. If these soil conditions are common in the local area soil borings might not be needed. If bore logs are needed they can be expensive. The travel time for a rig and personnel to come to site can be a significant portion of the cost. (It sounds like a personal installation. Try trading professional services to keep costs down.)
I’d also check with the tower manufacturer about the ability of this tower to withstand the higher wind loading. No use in having a good foundation with a bent up tower on top of it.
If they gave a typical foundation design, it will most likely have a disclaimer that if special conditions warrant you should get professional advice. This is special conditions. (If it was good soil conditions and the tower fell over, the manufacturer would claim that this proved special conditions and he was not liable.)
Rick Kitson MBA P.Eng
Construction Project Management
From conception to completion
www.kitsonengineering.com
RE: Tower Foundation on weak soils
Cheers Boo1