We are doing a typical anchor bolt survey. The building is approximately 20,000 s.f. with 150 +/- bolt groups.I am confident in our data collection as well as our accuracy, precision etc.etc.
My discussion involves manipulating the data before submitting our final report. Our reports are based on a simple grid. For each bolt we report the design coordinate, the as built coordinate and the North or South and East or West delta between the coordinates.
The results show a consistent delta in an easterly direction of 0.05' and in a southerly direction of 0.05'. Is it acceptable to translate all the as built data 0.05' westerly and 0.05' northerly prior to submitting the final report?
Regards
I would strongly advise against any data manipulation before reporting. Unintended consequences of doing so could be serious. I would recommend a complete report presenting the deltas, the average deltas, and the variation of each bolt from the average delta.
Even if all anchor bolts are uniformly shifted and therefore are dimensionally within tolerance to each other, they are not the only component of the building to be considered. Any structural/mechanical/electrical tie-in from outside the building grid could be affected.
I recommend complete transparency. Observe, analyze, report.
I had to as built 800 steel piles driven in rough ground that I layed out for a $800
mill expansion. If you are by the hour produce those ridiculous time wasting
design NE Set NE and Delta NE tables that absolutely nobody wants.
What they want/need in a Auto cad C3D of the Bolt centers and also the control you
used to pick up the bolts from as one autocad drawing. The building designer will
then Xref your drawing into his with the bolt holes of the girder/columns with clearance envelope then the autocad building designer will most like move the building slightly to suit the bolts
and then add in a clause that certain out of position bolt and thus the corresponding holes must be reamed and a heavy backing
plate used instead of the spec washer Blah Blah so to his spec on the side of the drawing.
THe dinosaur Delta XYZ tables are legacy junk specs written by project managers from horse and wagon days who manage jobs / write specs for work they have never Done
so feed the cad guy not legacy tables.
The AutoCAD Building designer is your real customer
the project manager is not the end user
who got there job for thats where the company figured out this monkey can cause the least amount of damage to the bottom line.
Send in the autocad of your shots and the control and the AutoCAD building
guy can make his building fit the as built bolts you picked up.
C3D has some best fit linear and curve or you could supply a best fit via some other soft that may save the building guy some hair pulling but just suggest this maybe some softs like Starnet may automate this but I suspect that the building will just slide his autcad building shape around until it seems good enough I suspect.
I have done some simple bolt fitting only about 200 total 4 parallel lines of 50 bolts using autocad C3D best fit routines
Peter K
i used to chief for industrial construction. here is the likely scenario....
the autocad guy is long gone. management wants assurance that the plates will fit over the bolts. those plates are already cut, drilled and welded to the posts. if they aren't already on-site they are on the way. the interest is if the west bolts are the correct distance apart from the east bolts.
Peter
I understand what you mean about sending them the CAD drawing. I probably will talk to the PM about that. Unless I'm wrong you are saying in essence that they will take the drawing and do what I suggested.
I agree Kent. The steel hasn't been shipped and its my understanding that its easier to make changes in their yard than on site. It would be nice to talk to the steel fabricator and go the CAD drawing route that someone else suggested. Makes sense.
At Fort Mac Bolts had to be within 3mm or 0.001' or 0.011" they are going to have to ream a ton of holes or shift the building or both.
Engineers are billable hours and the ACAD designer at Flour is expected to solve review this and YES you have to wait 2 weeks for a answer.
Peter K
More or less but
Those XYZ tables would have taken a week+++ to produce and CAD a lot less for 800 piles
I have a spreadsheet. I just export a xls point file and a little cut and paste. Quite easy.
Ditto. It's very fast to put together, and the project manager can see at a glance what is going on. I have been in almost exactly the situation you describe. It is a little painful to bear the bad (or at least imperfect) news, but the dividends can be huge.
In my case, I just swallowed hard and presented the information to the super and the project manager. That was not my favorite day. But...instead of finger pointing between me, the concrete foreman, and the ironworkers we just addressed the situation like adults. Baseplates had not been welded to the columns yet at the factory. Adjustments were made accordingly. The steel went up smooth as butter. I won the respect of management and the concrete and iron crews. And a bunch of hourly work rolled in from the same company. I am not making this up. It sucked, but it was worth it. I was in the field, and my stamp was on the line.
:good:
Agree. Experience of what & how the other guy will use the data is the key.
I would use "Transform" by PrimaCode to analyze the measured v. record positions and submit the results as part of my report. No cutting or pasting required...
"...NE Set NE and Delta NE tables that absolutely nobody wants..."
Attorneys and Contract Administrators love them for settling contract disputes.
I've never been there or done that, so this is just armchair musing.
But what seems important is data presented to answer these questions:
-Will the plates go over the bolts?
-Will the column be twisted too much?
-Will the column be tilted too much off vertical?
-Will the building be shifted too much from the desired location?
