Column Base Detail for High Tensile Load

[CTW]

I'd like to get some opinions on this column base detail I'm working on. I've got a high tensile load on a column (177 k). This application is in an industrial facility and construction is limited to down days. The foundations can be constructed in one day, but the structure cannot be erected until a week or two later. The problem is leaving a projection on the anchor rods cast into the foundation. Since the structure cannot be erected for a week or two, I need to protect the rods from damage. Placing some sort of structure over the rod projection to protect them will not be feasible. What I've come up with is to provide a pocket in the foundation say 6" deep with a width and length large enough to accomodate the anchors. The rods will be stopped short of the top by about 3". When construction resumes in a week or two to set the structure, anchor rod couplers would be used to splice the remaining rod length to anchor the column base plate. Once the column is set, the pocket would be grouted.

Any thoughts on this would be greatly appreciated as well as alternative details and suggestions.

 

[twinnell]

Good old caution tape wouldn't do?

 

[JAE]

For the high tension loading - is this a repeated load (i.e. where fatigue would be a consideration?) or is it from wind/seismic?

Just thought you might check on the mechanical coupler's ability to withstand fatigue/repeated/impact type loading vs. wind.

 

[civilperson]

How do you propose to protect the column when it is erected? Why not use the same protection method for the anchor rod projections?

 

[shin25]

CTW,

The connection detail that you are proposing is very common in the precast industry. The most popular coupling systems on the market are Dayton/superior, Lenton, etc. Most of the occasions bars with the couplers are left embedded in the concrete to splice with in the field to make a secondary pour. One thing needs attantion is that the threads inside the couplers tends to get dirty if left unused for a while. But this problem can easily be solved if the threads are capped.

 

[CTW]

Good responses. I feel more comfortable now.

JAE-
Good question about the repeated load. I'll have to check on the coupler's ability to withstand this. I should've stated this in the original post and my explanation will answer civilperson's question too. The application is a system of precast panels which form a barrier wall to protect the existing crane columns from the impact from a magnet used on an overhead crane. The structure supporting the precast panels is steel and the tension is the resulting uplift at one of the column bases.

 

[solo53]

Good ole rebar caps used to cap projecting rebar and they are yellow and OSHA approved for projecting steel. Ive used
many of them. Good Luck