Solar Farm Pile Layout
My company recently purchased a Vermeer PD10 pile driver for a solar farm project we have. My question is what is the beat method of layout for this solar work sounds like the industry standard is gps but is that gps rover layout or using machine control. I know some companies have used total station layout on smaller projects. Any information on this type of work would be greatly appreciated.
Rover layout, nails and feathers.
A robotic total station for small area is quicker - latency of measurements is quicker. That is, as soon as you plumb the rod, you have a go-to (delta north/east) distance. However, with huge area for laying out, multiple setups virtually eliminates the benefit of total station.
I'm currently doing support for a solar project that has `65,000 piles. There are about 30 drilling machines on the project.
Another company has the pile layout contract, but I've talked to their crews and closely observed how they're doing this work. It's all about production, getting points in the ground.
In my mind, it all depends on the tolerances expected. I have laid out smaller solar projects and always used a TS because I was staking and generating cut sheets with tight vertical tolerances.
When doing layout, I will use VRS RTK for rough grading but always go terrestrial when staking for finished grades. Sometimes hundredths matter, sometimes they don't.
Buy an RTK system and start putting in stakes!!! What could go wrong?
(most likely issue: datum)
I did some consulting with a firm that was trying to build robotic installation and maintenance machines for solar projects. Getting from Web Mercator to something I can layout on the ground was something they were working on with the software. Not sure where it ended up... 😉
The company I've been observing is using 2 one person crews. Each person has a rover and is loaded down with nails with color coded feathers in carpenter pouches. The feather color indicates the type of pile. Horizontal layout only. The exception to horizontal only is one point with an elevation about every 3000 points. The pile driving crews bench off this elevation point with a laser level to drive the piles to the correct elevation.
Each layout person sets in the range of 500 to 600 points per day with the goal of being around 1000 points ahead of the pile drivers. (Talking to the other company's surveyors, they say they have a friendly competition to see who get more set each day.)
I bid the layout work. I hadn't done this type of layout so I asked many questions on what the scope of work is. I was told by the project manager every nail had to be within "1/8th inch, with an elevation on every point." So that's how I bid it, with a per point price.
The company with the winning bid had worked on several of these types of projects in the past and came in with a per point price of less than half of my price. Now that I see how they're doing this, I can see why.
Each person has a rover...Horizontal layout only...one point with an elevation about every 3000 points...pile driving crews bench off this elevation point.
I bid the layout work...I was told by the project manager every nail had to be within "1/8th inch, with an elevation on every point." So that's how I bid it, with a per point price.
Well... it reiterates to me, project managers often don't really know how the work gets done. Typically I would talk to the superintendent - if they have experience, they know. In this case I didn't.
But now I know more. Watching and pondering, I might have a couple of ideas to increase efficiency. So, next time, now that I know the going price, I can bid to win.