[TowerTalk] Adjustments to Tower Base Pier J-Bolts

K7LXC at aol.com K7LXC at aol.com
Sat Jul 22 11:49:10 EDT 2017

>  Got a nasty situation here that needs some brain power to  resolve.  
this year, I poured two base piers for a pair of Pirod  self-supporting
towers.  The 140 ft. tower base has the  problem.   Unfortunately, the base
J-bolts on two of the three  equilateral triangle points are bent inward,
toward the base center by  1/8".  That 1/8" may not seem like much, but it
is.  In fact, the  template used during the pour cannot be removed.  During
the pour, the  J-bolts were double-nutted, one on top and the other below  
template.  Still, the force of the concrete pour managed to push out  the 6
ft. J-bolts.  As that was settling, I quickly moved the crew to  the other
tower as sunset was minutes away.  I did not go back and take  a level to 
bolts, thinking the template would keep them perfectly  straight. 

>  Each 6 ft. bolt is exactly 1-7/8" in  diameter.  Each protrudes 12" 
above the
concrete surface.  Moving  these huge bolts even 1/8" will take a Herculean
effort.  The template  holes are the exact same diameter and made that way 
minimize shift of the  type that occurred anyway.  The tower base section 
mounting holes  that are exactly 2.0" in diameter.  So, there's just a small
amount of  wiggle room.  If we can get the template off, then I know that 
tower  base will absolutely go on without trouble.  

>  Some  options:

1) Use an oxy-acetylene torch and apply heat at the point where  the J-bolts
exit the base, then pound with a sledge hammer.  Trying it  now without heat
is futile; we've tried and the bolts are going  nowhere.  I have no idea 
heating will do to the strength of the  J-bolt.  

2) Use a telescoping hydraulic cylinder (a.k.a.   hydraulic ram jack) to 
the two J-bolts against each other since they are  both leaning in by the
same amount.  What I don't know is how much  adjusting precision I'll have
when expanding the cylinder.  Do these  things move in very small 
What cannot occur is the cylinder  "jerking" the bolts to anything beyond
1/8".  These cylinders are  capable of pushing 30,000 lbs. and are typically
used on large earth-moving  front loaders
    Heating the bolts should be okay. I don't think  it'll appreciably 
cause a problem - but I'm not an engineer, just a tower  builder. Use a 6' or so 
piece of pipe as a lever to help move them. 
    The other thing you could do would be to enlarge  the leg holes to 
accommodate the slight off-set. That'd be what I'd do. 
Cheers & GL,
Steve     K7LXC
Professional tower services for amateurs

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