Construction Layout Quality Assurance

One of the best processes I have seen for QA checking field staking is to have the crew shoot the points they set and then (in the office) import those points into an "As Staked" drawing. Keep the points in this drawing separate from the calc'd points for staking- you can always overlay or x-ref the as staked points drawing on top of the calc'd points drawing and do a quick comparison to see how the staking went and what got done. Isolating the "as staked" points onto layers with the dates those points were set in the field also helps when backtracking to see what got staked on which day.

The most effective use of this system is when the "as staked" points are brought in and checked daily against the calc points for staking- I have seen many potential problems with staked points get identified in the office and resolved (restaked) in the field before someone else finds the mistake.

Hope this helps

Chuck

Thanks Chuck. Yes it helps.....we are, however, already doing that one...as well as actually putting each days stakeout on its own layer.

Photos are a great way of documenting what was set and what was written on a stake.

I realize it would be difficult to take a picture of every stake.

Back in 1998, we staked a bridge abutment for a contractor. We came back to check their forms before they poured the concrete, something did not compute.

We checked and re-checked, but no matter how we ran the numbers, the forms were 5' out of position. They had already constructed/braced the forms and tied the re-bar.

Things were very tense to say the least, some finger pointing going on. The stakes we set were missing.

We had to re-stake the abutment, assure the contractor that we were correct, then leave before things got worse. When I got back to the office, I remembered I had taken pictures of the stakes we had set. We printed them out and brought them back to show the contractor. He scratched his head for a minute, then admitted he had made a mistake. It was a metric job 🙁

If I hadn't taken those photos, we may have had to pay for the 2 days of labor it took to re-position the forms.

A picture is worth thousands.

I guess my point is an as-staked check is only good for determining WHERE a point is set, it does not verify WHAT was written on the stake.

Setting grade for the finish excavation for a large building, the ground was loose and the dig was too deep at one corner before we go there. I set the point to grade, using 30" rebar for that one because it stuck out of the ground so much and for some reason drove the guard stake to the same elevation. Called back out the next day and told we had staked the grade wrong and we were going to be buying the excessive fill removed and the gravel required to bring grade back to specks. They had called in their own surveyor who was set up with his level who showed us his notes and told his rod man to setup again on the rebar to prove them, when he did it was obvious that top of that rod was near the surface of the ground instead of being about a foot high. Told the other surveyor that I had set the guard stake at grade, so he smugly had the rod moved. Never heard any more about this. It was not brains or technique that saved us, more to do with paying attention to a feeling plus help from above.
jud

Seems like the surveyor always gets fingers pointed at them.

I have also found that it helps to walk the site with the foreman before and after the stakes are set.

If you can get them to look at the area first, you end up setting stakes that are actually benficial to the contractor.

Walking the site after allows you to have the conversation about grade being low, what the writing on the stake means, ect.

Having a daily diary as to what was done that day also helps. Example...at the contractor's request, 2 - 5' RP's were set for the sw corner of building A, area has been over excavated by approx. 2.5', spoke with foreman about issue...ect.

A focus on quality over speed that is built into the entire process. If you start loosing money on a job that is not reason to loose the focus on quality.

A focus on building quality relationships with the contractors and the guys that actually build this stuff. Explaining what layout means can help stop things from going bad and being on good terms can go a real long way when the do.

A focus on data management is key, be sure you are using the correct set of plans and revisions to those plans. Also be sure to watch for electronic to hard copy discrepancies.

If the plans are deviated from have a clear path of responsibility in writing and signed, dailies are good for this and are good practice in general.

Always check the match lines and structures, the problems are quite often there. Both the physical match lines and the paper ones.

Relationships and data management is really what it is all about in a lot of ways so far as I can tell.

Man that does sound great. I (forever hopeful) like to believe it's really about surveying, and what that ethically entails. What I ran into the other day while surveying some condo projects is the use and abuse of cheap help to do the layout.
It's not illegal for them to do their own layout...

..BUT QUIT SETTING THE IRONS AT THE PROPERTY CORNERS!!!

Two separate projects, two instances of their layout guy setting property corners. The
registered surveyor's irons make a great fit, the layout crew..best fit was 0.1'..then it got worse.