Hello All
I have recently started a new job, its a new highway, huge project. anyway, i work for the Engineer's on the project. which basically checks the contractor.
When we first came to site, we were introduced to the contractor's main surveyor, who gave us a briefing of what was going on. there was one thing that he said that stuck with me.
he said that they have banned automatic levels from being used by their staff, because total stations could do the job.
What are your thoughts on that, Remember it is a Highway, long distances involved.. let's discuss!
Replies
Hi!
You can use only total station if measurement accuracy of the excess does not exceed tolerance (the slope of the roadspecified in the project). other you should use only level.
hi
level used for checking/making vertical marks/levels with the reference of a bench/elevation it is true that total is a modern istrument but it can not estblish proper vertical mark/level but with acceptable diffrece it can do. as you describe that is main highway they are making fole you & yours team please beware from their folish mind
m akram shahid
if the total stations are high-performance, what's the problem? They are works for GPS and total stations.
I don't get it. Is the contractor saying that he doesn't need to buy Auto levels because he has a total station? Is it for checking difference in level between two points or for setting out? I presume by the time the contractor gets there the localisation (Stations) has been established and this certainly requires levelling. However there are programs in most total stations that will give you difference in height between two points. The Leica we use at work certainly does this for us. But to ban levels is strange. Come on!
As you probably won't be looping your traverse I would have to say it needs leveling. It's all about having that check available to view should there be any issue. If you are looping your traverse your survey software will tell you your closing error, so at least then you will know whether you are within tolerance. At the end of the day your job is to check the contractors work so it's not up to him to tell you your best working practice.
Oh I agree, but the contractor was not tell us what not to use, they themselves are not using the level. We have ordered 1 Trimble R8 GPS, 1 Trimble S6 Robot, and 2 Trimble DiNi (digital levels).
We were going to use levels anyway, especially where there are concrete works such as interchanges and so on. but i agree, a Level IS Necessary!
You would probably be okay without the level, but with the amount of liability involved in a project of this nature, it would be wise to document the precision of the control with an undeniably superior vertical instrument such as a digital level. Cover your "assets". CYA for short.
If you take reciprocal observations within 15min of each other the accuracy should be good enough for the job.
I think that a total station alone can not cover long distances without perpetuating inherent error. Perhaps utilizing GPS for establishing control at a reasonable interval along the route for a total station to use as a check-point would be in order. I know Dean Teska, RLS has done this and even used a digital level to test his theory and it was verifiably precise within 0.03 feet. I don't know the whole story, so Dean would have to share the details if you want more info. Banning certain surveying equipment, whatever it may be, seems inappropriate and a micromanagement-style mistake.