>> The base and rebar are sure different that the factory drawing I have for
the old rebar setup. The tower base is not separate from the rebar.
>> What size are the holes you dug?
>> Roger (K8RI)
The bases for the two Triex towers are my own design as I wanted provisions
for adjustable leveling and potential for future tower exchange. They were
designed to be stronger than the towers at failure. I had previously
modeled all the towers using finite element analysis to analyzed tower
strength under some different loadinf conditions and also to estimate the
maximum base loads at the point of tower's failure. I used those max base
load reactions + additional safety factor for the design of the bases.
The excavations dimensions were approximately:
66W x 72L x 94D
66W x 72L x 72D
54W x 60L x 80D
In some areas, I ended up over-excavating in the process of dealing with the
harder than expected clay. I just formed these up flat to the ground
surface beyond the base extensions and incorporated them into the concrete
pour so as to maintain the foundation bearing on undisturbed soil.
Had I acquired a test boring prior to sizing the foundations I would have
probably reduced the target dimensions quite a bit to take advantage of the
high bearing strength of my soil below 18". But at that time I had not dug
more than about a foot so I had not encountered the Caliche clay. In any
event, I won't be worrying about the foundation strength.... I'll try to
put up some more info on the tower bases when I get some more time.
Matt
KM5VI
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