How to measure anchor bolt in tight place

[SKJ25POL]

Can any body please direct me how and with what tool I can measure the dimeter of anchor bot at lost cross section for the rigth hand side anchor that is packed between the two vertical stiffeners?
And if anybody those how to fix it.

Thanks

 

[KootK]

How much of the bolt tension capacity do you need to resist the loads? Space permitting, I'd be tempted to bolt some straps/angles to the side of the pier and connect those to the column with weld plates. Bypass the bolts altogether. Any chance you know how the pier is reinforced?

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[Tomfh]

I generally count pixels to determine such dimensions. Be aware of perspective effects. And make sure you're measuring what you want to measure, i.e. steel not rust.

Maybe as KootK suggest you might forget about those bolts.

 

[TehMightyEngineer]

I'm with tomfh, put a tape measure or other known width in-front of the bolts in such a way as to minimize the errors caused by lens distortion, perspective, and so on. This will probably be good for ±1/16" if done well, possibly more given that you have a good angle to compare the rod to the tape in your picture.


Lots of danger tape in the background. What's the job if I may ask?

Maine EIT, Civil/Structural.

 

[CANPRO]

can you bend your tape into the gap and measure? If not, get an old tape and cut a piece and jam it up against the anchor. Alternate option - get some playdough and take an imprint <- only half joking about that, it may actually work (maybe not with playdough...I got some impressions done at the dentist the other day with a gel that sets up in seconds and then peels off clean and rigid, would be useful here).

 

[KootK]

Playdough would actually be a clever way to get the out of the page thickness which you'll need as well. Then you can take a high res photo of the mould and count more pixels!

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[TehMightyEngineer]

Interesting idea KootK. I've done similar to find geometry of dents in pressure vessel shells and it does work pretty well.

Maine EIT, Civil/Structural.

 

[MikeHalloran]

I've got a Stanley Powerlock 10' tape in my pocket.
The blade is only 1/4" wide, and not curled, so it won't support itself for any distance.
What it is good for, is measuring the circumference of things. The scale on the back is a 'pi tape', which reports an equivalent diameter for a measured circumference. Just wrap it around a pipe with the hook out, and read the back scale at the index mark.
It looks like it would fit around your bar.
I think it was less than 10 USD at Home Depot or similar.


Mike Halloran
Pembroke Pines, FL, USA

 

[Brad805]

You can't fit a caliper around the right rod? I assume you have measured the left rod. How much of the cross section has been lost?

I think the bigger question is your second question. How to fix, or rather, does it need to be repaired? My guess is this column supports a critical vessel or some other piece of equipment that is important to the plant process. The normal trick to this type of assignment is determining the actual forces at the connection. Drawings from this era are notorious for being lost, lacking information or being incorrect due to endless changes over the years.

 

[PSEPK]

One way, with out going for fancy equipment, is to use a thin metallic wire. Most probably there would be some space in between the rear portion of the bolt and the column plate, at least for sliding in a thin metallic wire. Letting the wire in from one side in the back space of the bolt, the wire may possible reach other side of the bolt, and may be even pulled out (although with some difficulty) using some stiffer metallic wire having a suitable hook one side (90 degree or more). Joining the both ends of the wire surrounding the bolt at the minimum diameter location, mark the joining point on both wires ends. You may measure the length of wire in between the marks, being circumference of the bolt. Determining size of the bolt will be a simple thing. Once the wire surrounds the bolt, you may use the wire even multiple times by sliding it up or down along the bolt shaft, to measure circumference at more than one locations. completely.

 

[charliealphabravo]

Would you typically remove the rust and paint in order to determine something as sensitive/precise as section loss?

 

[greencircle]

Wrap one round of masking tape and mark points. Peal it out and tape it on a flat surface. measure the distance between the points. You now have the total circumference.
Convert it to diameter.