Hello in this article we’ll discuss the art of moving dirt without automation. Then we will venture into applying lasers, cross-slope systems, sonics & GPS. Understand, I will not be able to go in-depth on each and every application. My goal is to hopefully help you to develop a better understanding of the automation tools and the overall application of each one.

I’ll phase this article in the same cycles of the typical job site. Those cycles being: boundary staking, clearing & grubbing, balancing stakes, balancing the site, underground staking, placing the underground utilities, re-balancing the site & compaction, finish stakes, cutting curb grade, finishing the sub-grade, placing the rock, finishing the rock, paving and backfilling behind the curbs.

The site is a 120 acre sub-division with your typical cut/fill balance site.

NOTE: This picture  is the sub-division area of my training site. Take a good look at all the stakes it would require to build this site manually. I’m sure we agree this is a staking nightmare, with top of slope stakes, toe of slope stakes, pad stakes and etc…

I also understand, due to extensive travel the regional verbiage is different, but the task is always the same no matter where you go even internationally.

The equipment we’ll use is:
1-815 compactor, 2-632 scrapers, 1-D6R dozer & 1-772D motorgrader.

Clearing & Grubbing
First we must clear & grub (strip) the site of trees and grass. In this case we’ll say the strippings (grass) pile will be re-distributed and used as top soil. We must locate the correct location for this pile. The strippings pile is usually placed in an area where there is no cut and no fill, labeled the daylight point and placed on the site for minimum re-distribution cost.

Site Balancing Stakes
The first set of stakes are usually within a .10’ and primarily used for balancing the site. These stakes will include lot corners and street layout, typically 3’ back of curb.

After the balancing stakes are placed the grade setter / checker and or laborers will drive the lath and hike-up the site. They will tie ribbons and paint lath so everyone can “see” the cut and fill areas.

2D: Not applicable

3D: GPS allows the contractor to stake this phase. Interestingly enough, you’ll stake the site differently than the surveyor would. You place the boundary stakes, locate the strippings pile and stake the day-light line. The difference is: the surveyor is looking for lot corners and street layout, due to the fact they are given points, while the contractors’ objective is a balanced site. I say this to make this point; if your fill area requires say 10’ of fill, your grade setter & laborers will end up spending most of their time in the fill area offsetting stakes. This is where GPS shines via grid staking. You already have the finish design surface, so why not slap a 75’ grid on it and quickly stake the fill area.

Come Friday @ 3:00 P.M. tell the scrapers to wipe out the fill stakes and work/compact the entire area eliminating the soft/un-compacted areas around the stakes. Then Monday morning, shift the grid by 20’ and re-stake the fill. I’ve used this method with success and I encourage you to try it. I enjoy watching the facial expressions of my students when I teach/show this type of staking. The number one comment is: THAT’S FAST AND SOLVES ALLOT OF PROBLEMS!!!

Note: This method focuses the crew to work in panels, while avoiding standing water.

Balancing Sub-grade
Once the site is staked the scrapers will start in the cuts while the fills are being ripped up, processed (watered and mixed) and compacted achieving OG (original ground) compaction. The motorgrader is making the haul roads, cleaning up the parking area and outlining the streets by following the stakes.   

2D: You could apply a laser system to the dozer and start cutting the pads that are close to grade, while the motorgrader starts outlining the streets and applying the 2% crown.

NOTE: the motorgrader system we’ll use is a laser, sonic & cross/slope system.

3D:Let’s take a quick look at how this operation would be different if you are using one GPS dozer, one GPS motorgrader and one walk-around rover.

Your motorgrader will start defining the streets & building haul roads. The dozer will start cutting the pads and pushing the excess material into the street. This way the scrapers can make long even cuts. The rover should be placing a few stakes (300’ apart) outlining the streets and controlling the cut and fill areas.

NOTE: Do not use your motorgrader to “show” the other machines or grade checker where grade is! That’s an expensive rover that should be working!

I’m skipping the underground for now due to the length of this article. However, do not think for one minute that your GPS system will replace the “pipe laser”. The utilities must be correct or you’ll dig it up and try again.

Rebalance & Cutting Curb Grade
All our equipment is back on site and we are ready to re-balance, water mix and compact the site. Our house pads are 90% complete with minimum cleanup. We save/uncover as many original balance stakes as we can, while the surveyor starts finish staking the streets with a 3’ back of curb offset. With grade checker and laborers we start working the edges of the streets, insuring all fills are made and compacted. We are trying to leave between 0.05’ and 0.10’ of cut for the curb machine. Basically, we are guessing with both ends of the moldboard.

2D: Using sonics we could string line the streets and use the cross/slope system to achieve the 2% crown. Stop! Wait a minute! Are you telling me you would string line the sub-grade finishing? Yep, and not the way you are thinking. I staple a mason’s line to the 3’ back of curb lath at the 2’ hike-up point. This method is quick, cheap and accurate. No steel pins, knuckles and wands used. The concrete crew will put those in later and yes, we’ll sonic off that line as well. The grade checker is now behind the machine “verifying” the grade being cut. Guys this is how I control the material savings account and have for many years. Most sonic devices will control grade to the hundredth of a foot provided the machine hydraulics are tuned correctly. Obviously, while the sonic is controlling one end of the moldboard, the cross/slope is controlling the other end. That’s profitable.

3D: Here’s another phase where the GPS systems shine. You can turn the motorgrader loose and go cut 3’ back of curb by following a pictorial line on the control box, while cutting the 2% crowned road.

Note: Providing you have requested the 3’ offset linework information from your data prep person.

Cutting curb grade is fast and some-what stakeless with a benefit few understand, that is: place the back fill material behind the curb 3’ offset and also gives the surveyor a place to put his finish stakes. By doing this, the stakes will be a constant cut with the benefit of having the backfill material in place. 

Finishing Sub-Grade:
To manually finish the sub-grade the motorgrader operator will guess at the correct depth beside the curb. We’ll use catch curb & gutters with 4” or 0.33’ of asphalt and 6” or 0.50’ of rock making a 10” section. We mark the end of the moldboard with a magic marker and do our best, while leaving the other end of the moldboard a little above grade hoping we don’t undercut the trailing end. While we’re balancing the edges the grade checker and laborer’s will hub/blue top the center line “crown”. We will make multiple passes following the grade/checker or cutting to painted numbers on the ground.

2D: Finishing sub-grade with a 2D sonic & cross/slope system is awesome! This is the most accurate method of finishing that I currently know of. First you’ll calibrate the cross/slope system and make a few finish passes in both directions, insuring an accurate percent of slope. While performing this task experiment with the pitch of cutting edge and find the best pitch/angle for the material you are working. You’ll find this is very important while using sonics. Then setup the sonics to cut 0.77’ below the lip of curb. Make a few passes and check the grade.

NOTE: True cutting edges are important. Have the grade checker check 3 places, add up the results and divide by 3, giving you an average. What? I want an average of the grade behind the cutting edge. Not take one shot and have me adjust to match that grade. Remember we are dealing with 0.01’ and we are controlling the depth of rock, then asphalt.

Once you match the grade checker, dial down to 0.82’ leaving 0.06’ for the finish pass. Dial in 2% on the cross/slope side and cut all the edges. Go ahead and balance as many square feet as possible and keep the roller working. Also keep that grade checker busy by checking the grade and placing a blue top on center line, say every 300’-400’. This makes a great double/triple check when you cross the crown.

Next, dial down to the grade you desire. We’ll say 0.85’ and leave 0.03’ behind the roller. 

3D: Setup the Base, Rover and check two or three control points. Setup the motorgrader and calibrate everything. You’ll make a few finish passes, check the pitch of cutting edge and make any adjustments needed. Then dial in 0.82’ below finish design and have the grade checker take 3 shots, add them up and divide by 3. Again, we need the average. Not one shot and go! Remember, all automation systems control the deviation “from” grade.

NOTE: Check the curb lip grade!!!!! (The place where the concrete and asphalt meet)

If this is incorrect, your 3D Model will not match the concrete and you now have to shoot the curb in a points file, and have an “As Built” model made! Get the picture?

Once the curb lip is checked, balance the site 0.06’ above finish sub-grade, making sure the grade behind the cutting edge is correct.

NOTE: All GPS systems will drift to some extent. Every manufacture will tell you their system is accurate within +/- 0.05’. That is okay, as long as you know it. If you are using a laser/GPS combination unit you’ll be able to achieve laser accuracies.

Placing Rock:
Here’s where you need to be methodical!! You should know the volume of rock required to complete the job. You should know how many tons of rock your crew can accurately place per day. You should know how many tons of rock the quarry can produce and haul per hour. By knowing this information up front you can achieve profitability each and every day.

Manually placing rock is a best guess by the operator with the assistance of the grade checker, laborers and etc… I often use this example: How many of you can tell me the difference in elevation between the carpet and concrete? And everyone leans over and pushes down on the carpet and the answers are: ¼”, ½”. I kindly say, “Are you feeling the wooden subfloor or the concrete?” Blank stares emerge, chins drop and I explain, “That is the same feeling a blademan gets when his grade checker shows him a 0.05’ fill and the moldboard doesn’t have enough material in front of it to make the fill.” Manually placing rock is an art!!!

We’ll use bottom dump singles, due to the fact end dumps are for dozers. First off, you’ll set the truck trailer gates for a 120’ x 18” windrow. You’ll start against the curb, place the material next to the curb and carefully work the material so you don’t put material up on the curb. The operator has two goals and they are: 1) put enough material against the curb with one pass, 2) leave a small (3”-4”) windrow next to the curb this way the weigh of the roller will be focused on the edge against the curb. Once the curbs have rock against them the middle is easy.

2D: Okay let’s make some money using sonics and cross/slope. Make sure the calibrations are correct, setup the sonics 0.50’ (compacted material) + 0.14’ (compaction factor) + 0.02’ (trim) = 0.66’ above finish sub-grade. (Smile we just picked up the 0.03’ left on the sub-grade) Dial in the 2% cross/slope and start placing material against the curb. The placement method will be the same as above. However, the operator now knows exactly where grade is. Placing material using a physical reference & sonics is one of the most profitable applications known in the automation industry. Asphalt paving machines use sonics!

When you drop back to finish and shave 0.02’ off the entire length of the moldboard, you’ll fully understand material control equals profits.

3D:Placing rock with GPS is very similar. However, keep the rover busy by checking grade and insuring you stay on the high side.

Finishing Rock:
Manually finishing rock is very slow and labor intense. The first thing you’ll do is finish against the curbs, by manually checking the grade. Once the edges are complete the ¼ point will be cut, then up and over the crown, chasing blue tops. Usually there are 2-3 guys on the ground chasing blue tops, pulling string lines checking grade and cleaning the edges. Just writing about it brings up long forgotten days.

NOTE: We could go into curb shoes, but you’ll need to request that information.

2D: Finishing rock using 2D is exactly the same as finishing the sub-grade, quick and accurate. If you understand the hydraulic tuning of a system, you’ll understand the need for that adjustment. If you don’t understand, a quick lesson is: The automation system needs to perform exactly like the person running it. Heavier down pressure while cutting sub-grade and less down pressure while finishing rock.

Remember you are controlling grade to the hundredth of a foot with sonics, so take advantage of the tool and control the savings account. Dial in 0.31’ below the lip, check grade often and finish with confidence.

3D: Finishing rock using GPS is just as fast as 2D control. However, keep checking the grade and don’t let the GPS drift factor get the best of you. Many of my customers finish using GPS and once the “grade” is correct, they turn the automation off and manually make a finish brush pass. If your system is capable of using sonics and GPS together, run the sonic on the curb and GPS the crown.

GPS is a fantastic tool when used correctly and enables the contractor to confidently control every phase of the job site. This includes weekly volumes reports via the foreman’s truck, machine productivity, and etc… An application that truly enhances our job sites is the ability to cut the flow-lines as soon as you get on the job site.

Hope this article helped and good luck to all!!!!