Monthly Flyover: How Does Drone Mapping Help You Take Big Project Surprises In Stride?

photogrammetry software

We sat down with Jason Tosi, Construction Technology Coordinator, at i+iconUSA, a diversified group of heavy-civil industrial construction companies. After spending the last 25 years in construction, he gave us his opinion on what drone mapping offers the construction industry.

What You’ll Learn:

In the interview below, you’ll learn about the applications he values the most for construction drone mapping operations, the trials of building out a drone mapping program in-house, and the importance of real-time data for bidding on projects.

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A: One of the biggest changes I’ve seen in data capture is the ability to analyze that data in a real-time fashion. With drone mapping, getting the snapshot in real-time is really the biggest and most impactful change I’ve seen.

Jeff Gonzalez – Granite Construction Webinar Q&A Interview

 

Q:  Jeff, please tell us more about Granite Construction and what you do?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Granite Construction is one of the largest heavy civil contractors in the nation. We’ve been around for over one hundred years.  We do everything from moving dirt, paving asphalt, structural concrete, underground work, you name it.

 

 

Q:  How did you get involved with Granite in your current role?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Growing up, I always saw green Granite trucks working on the side of the road that put the company on my radar. I ended up going to Fresno State and studying construction management, and Granite was very supportive of our program. Granite sponsored our heavy civil competition, aka the Reno Competition that goes on in February in Reno, Nevada. All the construction management schools in the nation come together, and they put together proposals on a project that Granite has done in the past. That’s what really got me interested was the type of projects that Granite works on. They’re responsible for that competition, and our heavy civil team from Fresno State worked closely with their project managers and engineers to come up with a detailed proposal on one of the projects that they actually built.

 

Q:  How did you get involved with drone mapping?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Drone mapping was always a hot topic while I was in school. There was talk that drones would take over and be able to do all the topos for us and all the mapping. I understood that planes could do topos, so it made sense that drones could capture them too.  The technology side of it got me interested in how it all works.

 

Q:  What is the project that you and Granite are working on right now?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Granite was awarded a 10 million dollar job in Santa Paula, California. It’s called the Harvest at Limoneira Project. It’s a rough grading project for a master community. There’s going to be about a thousand homes in this community, a school, parks, commercial center, apartments.  The project is about 360 acres and five million yards.

 

Q:  Was the size of this job what made you interested in using drone mapping for it?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, definitely. I knew it would be a perfect opportunity to experience the potential of drone mapping.  It made the most sense to use a drone to be able to help efficiently track progress and quantities.

 

Q:  What specific reports or data were most helpful for tracking quantities?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  I wanted orthos, which are all of the pictures stitched together.  The DXF files and the point clouds so I could compare different surfaces to the existing topos and  design fileto track progress and come up with our quantities every month.

 

Q:  Why did you decide to use a managed drone solution rather than trying to build something out internally at Granite?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Cost and time. To be honest, I don’t know exactly what it takes to build a drone or to get the drone to be able to fly itself and process the photos, stitch them together, and come up with the DXF and various files that I need.  I didn’t have the time on top of what I have to do for the project to get it all done the right way.

 

Q:  For the drone mapping workflow that you do have to do on your end, what does the general sequence look for you to use the drone?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  You guys supplied the drone for us and the software to fly the various maps. I fly the whole site once or twice a week, especially on the first and 15th to come up with our bi-weekly, or bi-monthly quantities.  If it’s our first time flying an area, it starts with setting ground control points. That’s painting an X on the ground, dropping down a painted plywood X on the perimeter, or just using our storm drain utility holes as targets for the drone to recognize, and then shooting the points with our rovers and getting the ground controls over to you guys.

Once the GCPs are laid, from then on, it’s pretty much just set up the drone, tell it where I want it to fly, where it’s taking off, and it flies, lands itself, I take the pictures, and I upload it to your guys’ site for processing.

 

Q:  Do you think you’d be interested in using PPK on the future to avoid the necessity for GCPs?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Oh yeah. Granite’s never used a drone on the type of project like this to come up with quantities, so wanted to see the cost-benefit and time benefit of utilizing the PPK versus using ground control points. After seven months of being on the project, I think I’ve flown it at least 60 different times, so yeah, the PPK would definitely be great for our next job.  I have 60 ground control points on this job, and I would say half of them are permanent that I don’t have to worry about. The other 30, I got to check to make sure a scraper didn’t run over it and take it out, or a water pool didn’t go over it and wash away all the paint that I just painted. It takes me about 30 to 45 minutes to check on all the points that I know that are potentially going be either destroyed or need repainting.

 

Q: Can you describe the operational difference between a standard drone and a PPK drone for our audience?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  We have a permanent base station that we set up on our job trailer. PPK talks to our base station, and the drone doesn’t need those ground control points that tie into the site.

 

Q:  This was Granite’s first time using drone mapping.  Was there any skepticism about what the quality was going to be like maybe from surveyors, grade checkers, or other people in your organization?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, of course. I mean, especially the people that are seasoned and used to doing things a particular way. There was some skepticism about it, but we did some trials to compare an area that we shot with our rover with just a ground control and the same area with the drone.  What we found was, the only difference is that you have more detail with the drone because there are a lot more points that are being recorded compared to shooting with a rover. Let’s say you shoot a 100 rover points, with that area; I think the amount of points that the drone produces is probably 10 to 20 times more than that, so it just gives you a lot more detail. It’s giving me more detail. It’s showing more highs and lows compared to if you shot nothing but the low points with the rover.

 

Q:  What kind of tolerances do you look for on this type of site preparation project?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Our tolerances on contour grading .50’, .20’s in the streets, and a .10’ on the blue top pads.   I can fly at 400 feet for contours and streets but whenever I’d go and fly the neighborhood, I’d fly at 200 feet to 100 feet to get the tolerance down and get better accuracy.

 

Q:  Our client success manager would be proud.  She always says to fly low and slow for the best accuracy.

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, definitely.  It just depends on your needs.  If you fly lower, it’s going to be more flights on a 360-acre project. Say it takes four flights for me to fly the entire site at 400, it’s going to take me eight flights to fly it at 200, so it’s only worth doing when we really need that increased accuracy.  I normally do four flights at 400, and then I have my eight flights at 200 for the areas that I need tighter accuracy.

 

Q:  Were there any big surprises during the project?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, definitely. On April 5th, we hit an area of impacted soil, and pretty much from April 5th to August we’ve been excavating the impacted soil that we found. The potential of impacted soil wasn’t shown on any of the geotechnical reports, so it’s was a surprise to the owners and us. We looked into the historical aerial photos and talked with farmers because the site used to be an orchard for lemons and avocados. Back in the day they used smudge pots, which are pots that they would fill with kerosene or diesel.  They would light them on fire to heat up the orchards, so they don’t freeze in the winter. There was about 20 thousand of them on the site all over the place, and they had oil lines running from where the highway is and where the railroad is next to the highway. They would bring in huge amounts of oil on rails and pump it up through the site to above storage tanks. I think those got outlawed in the 70s, but from the 1900s to the 70s they were pumping oil all throughout the site. Those lines either leaked over time, or they didn’t do a good job of mitigating all the oil that leaked out when they stopped using them. It hit about five areas creating all this impacted soil that has had a massive impact on the project. We’ve had to excavate from 100 thousand to 200 thousand cubic yards of material out of each one of the five areas that we’ve hit.  We did the impacted material on time and materials, but as we got deeper in certain areas, we had to make them wider with the scrapers, so we had to take overburden out, which we were being paid on contract quantity for the overburden, but impacted soil was on T&M.  We had to take everything surrounding the impacted soil out with scrapers to make the slope safe enough for everybody that was down there testing the soil and breathing it. We had to get those to safe slopes. With that, we had to take overburden around the impacted material out.

 

Q:  Was the drone data useful in dealing with this surprise to ensure that you were compensated for the unplanned work?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  The drone let me see the limits of where we were excavating, and I was able to take that out of our quantities for overburden. Without that, it would have been really tough because we were always chasing this impacted soil, and as we chased it, we had to take more over dirt, and we had to prove that to the owners that we’re taking out this much over dirt, and show this impacted material that’s on T&M’s is not included. We would have had to have the grade checker on-site full-time, every single day, to track the limits of excavated, impacted, and overburden that was excavated with our scrapers.  Without the drone, it would have been challenging.

 

Q: Did having that data help with cash flow on the job?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  It helped a lot because we were able to prove to them that we took out this much overburden and that it wasn’t the impacted soil, and we were getting paid contract on it. I mean, we were excavating over 500 thousand cubic yards of material, so at two dollars a yard, it had a significant impact on cost. Being able to track that and submit to them, hey, this is how much yardage of overburden we took out that we agreed to on contract, and being able to prove that, that none of that was impacted, was huge.

 

Q:  What financial impact did this information make?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  It was definitely in the millions.  With our T&M tickets every day and our yardage that we would take out every other day to remove overburden, it was a substantial financial impact. Without the drone, it would have been challenging using rover shots and documenting that and being able to prove that to the owner, that quantity that we aren’t trying to bill for.  If we hadn’t put this in our bid, we would have had to pay for someone to come fly and do it out of pocket, at a cost that we didn’t expect to incur. But if you build it into your bid, you can use it and see how it works and how the investment pays off.

 

Q:  Can you compare how much ground a single surveyor can cover in a half day versus a drone?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  The drone would take 15 minutes to get a to get a detailed topo of 100 acres and have it processed and back in a day.  To topo the whole site with the rover would be insane. It would take many days. I wouldn’t even fathom it.

 

Q:  What do you think would have happened on the project if you hadn’t had any drone data?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  I wouldn’t sleep. I would just organize data 24/7.  Fortunately, with the drone data, it’s all right there. The data doesn’t lie, and the quantities are very accurate when I take out the impacted material, so it helped out a lot. Plus, these holes are about 50 to 60 feet deep and having the guy on the ground having to shoot those slopes, would be really dangerous for him. With the drone, you eliminate the safety risk.

 

Q:  How did the customer react when you presented them the data showing the unexpected additional work?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  They were a little shocked, but it is what it is. That’s what we agreed to, but it helped for us documentation wise. As the hole progressed, you can see the limits of excavation that we did on T&M, and what we did on contract work. They understand what the financial impact on the project was because of this impacted soil, and that we have to remediate and get rid of it.

 

Q:  Has drone data been useful in any other aspect of the job?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, definitely our haul road planning, especially around those 5 impacted sections. Right now, we have one of them filled up. We’re working on the second one, and we’re moving on to the start of the third one right now.  We have this thing in our contract, as well, called station overhaul. For our bidding purposes, we have to commit to the owner a certain amount of feet that we are saying we’re going to move this dirt. We plan on flip-flopping this whole job within a certain amount of feet, and every 100 feet that we go beyond that, due to a design change or impacted soil change, or some other unforeseen condition, we would get paid an extra five cents per cubic yard, per 100 foot station that we would go over it.  Every day, when we track our T&M tickets, we are also putting together our station overhaul maps for our scraper hauls around these holes and having to pull soil from places that we did this job to pull it from. Just tracking that and being able to use the measure tool to identify with the pictures helped out a lot. That was another positive impact on the financial side of the contract.  The drone data provides long-term documentation, too. A couple of years from now if something comes up, you can always go back and look at the maps and compare flights across different dates to prove to them what actually happened. Without the drone data, it would be really hard to do that.

 

Q:  Were there any other specific drone data tools that you found particularly valuable?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, when I do my client cards for quantity of finished grade, I can see on the drone which super blocks or blocks pads we finished in those two weeks just based off the last drone flight compared to the next one. It helped a lot being able to just draw a rectangle or square of the pad that we finished and instantly get the data.  You guys also make it easy to export it into Agtek. I’m only looking for two files, and that’s the DXF files, which is the contours generated from the point cloud, and the Geo TIF. The Geo TIF’s huge. Geo TIF is all the pictures stitched together, and I pretty much import that into Agtek and the DXF file. It’s an excellent visual aid, and it helps with a lot of our maps.

 

Q:  Have you found any other applications for drones on your job site?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  For job progress, it’s an easy way to show owners and upper management where we’re at and what’s going on on the site. I use it to take pictures and videos, and I post it online to show what we’re doing. It has been very helpful.

 

Q:  Is drone data important for dealing with subcontractors, or are you guys actually doing most of the job yourself?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  We are responsible for the rough grading portion of the job, but other contractors are doing the paving and concrete and what not.  They’re not our subcontractors, but we provide all that information to the owners so they can track how much pipe is being laid every day and how much square feet of asphalt is being paved and linear footage of curb that’s being poured. The owner’s very happy with how they can see the progress from the data and maps that we provide them.

 

Q:  Would you recommend a managed drone solution for other companies like Granite?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yes, for sure. I couldn’t imagine doing a job similar to this without one.  The drone solution has paid for itself many, many times over.

 

Q:  Did you train for your FAA Part 107 commercial drone license with us?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Yeah, you supplied me with all the information I needed. I studied for it maybe three days before I took the test and passed it with flying colors.  The questions are just common sense. It keeps people that don’t know what they’re doing out of the air for safety. It covers where you can fly and where you can’t fly.  Just be smart, don’t take any chances, and be aware of your surroundings. Study your sectional maps, and you will be fine.

 

Q:  You came into Granite already knowing more about drones than most people. Given that you’ve been following the technology for years and are at the forefront of it, where do you expect to see drone mapping 5-10 years out from today?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Just having it autonomous and using PPK instead of GCPs is amazing.  I see it continuing to go up and progress rapidly. It’s pretty advanced now, but with all the other features that are coming out the opportunities are endless.  The sky’s the limit.

 

Q:  Jeff, is there anything else I should have asked you or that you would like to say to our audience?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  For people out there, don’t be scared to use technology. The world is changing. If you don’t keep up with it, you’re going to get left in the dust. That’s what I’ve realized.  After researching it, using it, and seeing the real benefits, there is no doubt that drone mapping is the future.

 

Q:  Jeff, I appreciate you sharing your experience with the audience.  Do you mind if people reach out to you if they have follow-up questions?

Q: Being a vet in the construction industry, what are the biggest changes you’ve seen in data capture technology?

A:  Sure, feel free to reach out to me at https://www.linkedin.com/in/jeffgonzo I like collaborating with other people to share insights and hear other points of view.

 

You can listen to our live interview with Jeff here. This Q&A was adapted from the webinar How One Contractor Used Drone Data to Save Millions on a Project.

Interested in hearing more from experts and thought leaders in drone mapping? Check out the last installment in the Monthly Flyover series here about how drone mapping impacts mining efforts. 

Drone Mapping for Earthwork Companies

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