Contractor calls me out to figure out why his dirt sub is all up in a huff. Seems the topo is bad, there's 4,000 extra yards of dirt out there that's gonna hafta be hauled off. So I take a look at the original topo- seems legit, plenty of benchmarks to check into. Meet the dirt guy's surveyor on site, we walk around for a bit taking the same shot for about an hour- him with his gear, me with mine. Then I bid him adieu and proceeded to check into all the control and do a couple hours of rough grid work to get blind samples against the original surface (which I happened to get hold of in cad). Dirt guy sends me his spots, they match mine for all intents and purposes. I run spot elevations off the original tin, they all (100+) fall close enough for me to be comfortable that the first survey is good. Then I generate contours off my admittedly small number of shots, they fall awfully darn close to the originals.
Talk to the contractor, tell him I'm satisfied the original is good, not sure where the extra dirt number is coming from but it's not from bad surveying on any end. Sub gets in a bit of a lather and lists the following reasons for not only the original bad survey but for my ineptitude:
1. He shot 350 points, I only shot 100. (Original topo was over 2,000).
2. Surveyors only know how to shoot grids, he shoots breaklines and natural features (again, guessing he didn't look at the original too closely).
3. I run network gear, he uses a more accurate base setup- because in this technologically advanced world you have to be at the very forefront. (Not kidding- that is almost verbatim.)
4. Contours are irrelevant- his dirt software makes three iterations over each spot elevation (whatever that means- And which led me to ask him if he'd ever made a sandwich without bread.)
5. His software is never less accurate than .5'- keep in mind we're talking a theoretical two tenths bust on the site.
Luckily, the GC told him to calm down and it wasn't a big deal one way or another.
How'd anything ever get built back before everyone had an antenna? And sorta knew how to use it...
Can't resist. Been a long past few weeks for this hombre.
I'll double down that my GPS is better than that other GPS. Let's get some more GPS to check it out before it starts coming to $$$.
Build the project first. Keep leverage in your pocket so they owe you at least the final sign off $$$. Short of that you lose your leverage. Once things are done it's amazing how the dust settles and life moves on. Not all clients are good clients.
...just sayin'... 😉
Interestingly enough the water and sewer authority here requires a legal declaration from all of the contractor's sub contractors that they have been paid before the authority makes the final payment to the main contractor.
That is standard practice here to ensure the subs can't file a mechanic's lien (private only) or stop notice (a lien on the source of funds).
Are you sure you weren't in California on this job? We just did a job where the grade setter came out and told us that our original survey was bad, and we were short 20,000 cubic yards of fill based on his numbers. I came out to check, even did a new topo of existing conditions, and couldn't see where the number came from. Our new topo matched the old.
He continued to argue that his numbers were correct, and that his data collector-generated surface showed that we made a huge mistake somewhere in the topo.
They hired another survey firm to come out and check us, and they got the same results we did. The grade checker proceeded to then say were both incorrect and that we clearly weren't putting breaklines into our drawings or picking up the right points.
My first assumption tends to be that I messed something up, but in this case, I just can't see it. We eventually finished that phase of the project without the import.
Back in the 1980s we were in the middle of a 55ac lake subdivision and the State required the developers to make do some maintenance on a 1400ft long dam and define the spillway area. The entire dam and surrounding area was sand so the slope was designed around 1:3
When it was about complete, the dirt guy had moved well over 100,000 yards of dirt more than planned and the developers came to us wanting answers.
We went out and checked and the backside toe of the dam was about 80ft farther downstream than we had staked on the ground and they had added nearly 100ft to the pipe thru the dam that flushed the lake putting the slope above 1:4
The dirt guy had just simply eyeballed it in the way he wanted it. The project looked fantastic and in the 30yrs since it is holding up like a champ.
Could this "extra" volume be material that was supposed to be removed under a separate pay item such as clearing and grubbing?
Gotta love truck counts....
the more noise this guy makes the more i suspect he's trying to cover for underbidding the job.
but, i don't know- don't really want to know. all i was asked to do was go check the original topo done by others. i went in not knowing what i was going to find, nor determined to make any particular party look good or bad. i told the GC that, imo, if he hired 10 surveyors that at least 8 of them would give him the same topo as the original (didn't want to make it sound like we all know what we're doing all the time. 😉 )
Once, when I was with another company, a dirt contractor has moved waaaaay too much dirt on a subdivision construction site and accused me of staking it wrong. All the bosses met on site with an excavator, and we marked a few of the points where stakes had been set. I'll never forget the guy five feet down in a hole handing a stake to the people on top which read C-3.5' That was then end of the discussion.
> the more noise this guy makes the more i suspect he's trying to cover for underbidding the job.
Many times the low bidder's profit lies in anticipated change order work rather than being built into each item of work.
I don't think I have been on a single job where the contractor hasn't thought that they have hauled more material than the plans showed. Every time the suspicion is based on truck counts rather that survey data and usually shrink/swell issues are not taken into account.
I would suspect that they are doing their volume calcs/material ordering from the sub-base instead of finished grade or similar. I have seen it a few times when a goon with a rover is out staking what he thinks is sub base, but he is actually staking finished grade. Doh!
> I don't think I have been on a single job where the contractor hasn't thought that they have hauled more material than the plans showed. Every time the suspicion is based on truck counts rather that survey data and usually shrink/swell issues are not taken into account.
Well of course a truck count will be way high!
Earthwork is paid for by excavation and embankment, native material in place prior to excavation (original topo) and compacted material in place after embankment. The same cubic yard of material (solid rock) may swell 40% upon excavation, then shrink 10% upon placement and compaction. Some material may have its moisture content altered (sands)for higher density upon compaction and affect shrink/swell calculations. Subsidence of native materials below an embankment can appear to cause significant shrinkage of embankments, especially a year or two later causing the whole house of cards to fail. Clay behavior is especially difficult to predict due to moisture related changes, ask any clay tile maker. Discovery of loess or other unsuitable material should be handled by special provisions in the contract, if not, everybody goes to court over a bad contract.
Earthwork is nowhere near an exact science because the material is so variable. Luckily, the surveyor's responsibility is to provide a before condition=topo, construction staking reflecting the engineer's plans, and an after condition=asbuilt topo. Nothing more. The (soils) engineer is wholly responsible for shrink/swell predictions, if any, shown on the plans. The earthwork contractor should build in an error factor in his bid based on quality of the plans and uncertainty of soil conditions.
I've done some big earthwork carefully crafted jobs (multi year phased superpad hillside subdivisions and new roadway cuts through mountains) where the earthwork contractor ends up 100,000 yards short (bad) or long (good if it's quality material) and there's not a peep from him because he's a pro and realizes a 5% error is part of the game. Ya win some, ya lose some.
OTOH, on smaller jobs where there's a 10,000 yard shortage (20%) because of sh*tty plans I've had contractors come after me claiming it's my problem. He's new to the biz and will lose his ass because of import costs so he's lashing out at anybody on grade. I respond to the twit by saying sue me over my topo, construction staking and asbuilt surveys, see you in court if they're wrong. Your problem is with the engineer, not me. Usually silence after discovery.
Showing them this graph generally shuts them up:
OK, I'll admit we f**ked up on a job where months after control was in the dirt guy excavated our daily (close in) benchmark and *put it back in* so all subsequent construction staking was off by 0.3'. The dirt guy kept complaining he's digging deeper and the roads and hydrants would stick out into the sky (love him for giving us an early alert). We woke up, checked our outside control, and paid the guy $30,000 to haul dirt into the area he'd just removed it from. The boss was ecstatic because we caught it so early and saved potentially hundreds of thousands.
You are correct, shrink/swell is usually addressed in the contract, as well as measurement methods and payment. Contractors are well aware of issues surrounding in-place vs. loose, but for some reason they always think they are getting the short end of the stick. Especially when you tell them that they only getting paid for excavating the material - not moving it and placing it as roadway embankment.
