Activity Feed › Discussion Forums › Education & Training › Slope staking on exam
Today, people abhor the thought of doing iterations to find an answer. Why can’t you get the absolute correct answer on the first calculation, they ask? The real world doesn’t have absolutely correct answers on the first attempt. Refinements are necessary.
It’s good to know how to slope stake with a rag tape and a level, just to be firm on the fundamentals and to be able to knock out the occasional quick need on a construction site without poking around on your electronics forever.
Did my share of slope staking early in my career, but never enough to approach anything like the speed and confidence of the old timers. From my 9th Edition of Wolf and Brinker’s Elementary Surveying (p. 533): “An experienced surveyor employs only mental arithmetic, without scratch paper or hand calculator.” Reading that as a young man, I could only shake my head. Worked with a few of those guys, but never reached that level myself. Few in the future ever will.
For small projects, those who think it’s always faster to comp it up on the laptop or your field controller: It’s only faster for you. Those who haven’t worked in the field with the analog generation have a hard time imagining how fast those guys could move.
Frozen North, while it’s true calculating slope stakes mentally was SOP, the complicated design often accomplished with CAD started to make it virtually impossible to do. Hwy slope stakes often are more of a story book anymore than the slope stakes I was used to doing. It became important to have templates that could be attached to the computer files the DC uses to get it done efficiently.
It’s good to know how to slope stake with a rag tape and a level, just to be firm on the fundamentals and to be able to knock out the occasional quick need on a construction site without poking around on your electronics forever.
Did my share of slope staking early in my career, but never enough to approach anything like the speed and confidence of the old timers. From my 9th Edition of Wolf and Brinker’s Elementary Surveying (p. 533): “An experienced surveyor employs only mental arithmetic, without scratch paper or hand calculator.” Reading that as a young man, I could only shake my head. Worked with a few of those guys, but never reached that level myself. Few in the future ever will.
For small projects, those who think it’s always faster to comp it up on the laptop or your field controller: It’s only faster for you. Those who haven’t worked in the field with the analog generation have a hard time imagining how fast those guys could move.
My Monroe calculating machine manuals will often say there is “no mental effort required” then proceed to describe a long complicated process. I guess for them “no mental effort” meant the absence of longhand calculations or using Log tables.
I wish i had a nickel for all the slopes stakes i had to set. So many little tricks to getting that catch point and making things move along quicker. We had a set of plans. With profiles and such. Sit down and compute grades at cl then use the different cross sections to get out to the toe or top of slope are and have that grade/elevation know your slope 3:1 or 4:1 etc. compute rod readings then simply subtract and x the required slope move in or out until you catch. Geezers i hope i didn’t miss anything. It has beea long time. But clapping 90’s right angle prisms pulling two chord distances whatever it took to get the job done. Now points points points. Heard a surveyor complaining the other day. He said with robots we have no mentoring in the field anymore. I have crew chiefs that cannot compute anything and can’t find one to hire that can. I said are you the LS. He said yes. I said well isn’t your job to mentor. He said its a crew chiefs job. I said i had good crew chiefs coming up but the LS was the main mentor and the main one testing me to see where i lacked. The crew chief most definitely helped. But when i look back and see the owner the main manager all Pls as the main teacher and mentor its not the robot or rtk fault. Now i try and set my chiefs down every chance i get and teach what little i know. Somehow we have to get that done in this profession or the profession will wither on the vine.
Very good discussion above of button-pushing vs. having a clear mental picture of what’s going on.
Slope staking was one of the first things I had to learn when I started work on the County survey crew in northern Minnesota in 1963. There was no training as such, and asking questions was not encouraged. I had to listen to the experienced guys, watch what they did, and figure it out.
I would stand at the road centerline, holding the rag tape at a distance given to me by Stan, the head chainman, who was on the rod. Stan was astonishingly quick at mental math. Ed, on the Dumpy level, would call out the cut or fill. Before Ed’s mouth was fully closed, Stan would have computed the new offset from centerline and called it out to me.
Cut sections of the road always included a ditch. The ditch usually was of a fixed depth, say 2 feet below the road shoulder. With a 3:1 slope from the shoulder to the ditch centerline, the ditch centerline would be offset 6 feet from the shoulder.
But in some cases there would be a “special ditch,” on a flatter or steeper profile than the road, to match up with a cross culvert or something of that sort. That ditch centerline would not be parallel, and this affected the slope staking. In those cases Ed would compute the ditch centerline offset at each station and call it out to Stan, along with the cut.
After several days of doing this, I was discussing slope staking with Pat, the other new guy, who didn’t know any more about it than I did (his job was to carry a bundle of lath and follow Stan around). Suddenly I got a mental picture in 3D of the cut or fill slope as a plane, slicing through the ground surface at an angle. After that it all made sense.
All these points were staked with 4-ft. lath, leaned away from the road centerline at a 45-degree angle. That made it easy for the dozer operator to tell they were slope stakes.
We generally staked 2:1 cut slopes and 3:1 fill slopes. Most of the soil in northern Minnesota is clay, and those worked all right. Softer soils would of course have required flatter slopes.
To jog those old memories, follow the link. Back up to p. 133 to get the full picture:
Slope staking still has its place even now that machine control is common. Every once in a while I set slope stakes before construction so the engineers can visualize the impact of their design on sited before any dirt is moved. On some railroad jobs we will stake out the catch line based on the conceptual plan to make sure we have the correct coverage for the engineers. I’m not saying I use a level, but the technique is the same with a robot or GTK.
I tell people every time I’m walking around to certify the subex that they don’t need me. The only need a grade rod and a tape measure. If we didn’t have insurance they’d be doing it everyday. Sad but true. It does take a few people that know what they’re doing and care to do it right, but post COVID I’m always surprised and even shocked at some of the things I see And get asked about when I’m on a site.
To jog those old memories, follow the link. Back up to p. 133 to get the full picture:
Excellent book. The slope staking procedure is much the same as what we did on the County crew in the 1960s.
We didn’t use any of the prismoidal formulas given in the book for calculating earthwork volumes; just the end areas. The sections were plotted on graph paper and areas obtained with a planimeter. Volumes were figured with a big Monroe mechanical calculator, operated by a crank. It was very similar to the one Dave Karoly has.
The fill volumes were all multiplied by 1.25 or 1.30 before putting them into the calculations for earthwork balance, that being a compaction factor for newly-placed fill as opposed to undisturbed soil.
If the earthwork for the project didn’t balance, the engineers would adjust the design grade here and there. New sections would be plotted for the adjusted areas and the calculations re-done.
After thinking more about the problem and re-reading a text book on the subject, it seems the key is to ASSUME that the ground is not too far from level.
With only the given information, that is necessary to work the problem. There could be side hill profiles where the road itself would be in cut and still have the given measurement. The text book showed such examples.
I still quibble with some of the wording. “The finish grade is ..” No, it is to be, not existing.
“The test point (road edge) …” Isn’t the test point where the rod is held? The answer should say “The planned road edge is above the ground at the test point by 2.64 ft.”
.welcome to the trickery that is the FS.
Interesting. I’ve written my share of test problems and argued about the wording on many more from standardized tests. Before I argued I always asked myself this: If the wording were changed to what I wanted, how would the student’s understanding and solution of the problem be changed?
Part of the solution to this problem is to determine whather the road is above or below the test point. Having that given would have eliminated 2 of the 4 possible answers for some otherwise ignorant test takers, making a guess a 50-50 proposition instead of a 25-75 one.
To get a feel for how some teachers “teach the test” and achieve sterling test scores without thorough learning, see how you could eliminate possible answers without solving the problem.
@jitterboogie for sure. I think that some of the test writers all get together and have liquid that takes them through mistakes they made and so bam the exam question is created. I am pushing one of my young chiefs new chief hard on getting ready for FS exam. I tell him they will give you all sorts of numbers and such that can lead you to an answer but not the answer in which they asked. Ya have to pay attention to details for sure. A whole two paragraphs describing something enough given numbers to solve the worlds problems and they only want something that has nothing whatsoever to do with 99% of the given information. I am a slow reader so i had to focus.
@mathteacher you are so correct. I used that strategy myself. I looked at the question understand what they are asking eliminate the ones it cannot be from mostly experience. Then begin to solve. I used my dry erase marker and that plastic thing they gave us for the exam. I made my best educated guess of the answer before solving because most of them are right there i made the right call most of the time and when my solved answer didn’t match I checked and solved from a different way as to check my fat fingers on the calculator. I mashed several wrong buttons had the math correct had the correct flow and order just mash the wrong key. Garbage in garbage out. It’s actually a good test I truly think they did a very good job of testing my knowledge and problem solving skills. I am a poor test taker and i just have learned take a deep breath and truly understand what they are asking. I am very poor grammar but usually do well reading technical manuals for some reason better than grammatically correct things. Guess my brain is wired that way. Have to say the wife truly helps a bunch. When i was taking a college course in technical writing she being a grammar beast said don’t worry you will be fine most technical manuals are not written grammatically correct for a reason.
Just like the real world. Lots of info available, little of it useful.
Part of critical thinking is separating what you need from what you don’t need, a skill that’s regularly needed in surveying i would suspect.
In Problem 7, the stationing is irrevalent, otherwise I don’t see anything superfelous in the problem.
There are three distractors in the problem, though. That’s testing speak for the three answer choices that aren’t correct.
Go figure.
@mathteacher maybe i need to come pay you to tutor me for my next exams. Bad thing is it has taken me so many years to get to where I needed to be. I do give the usmc credit. It forced me to overcome my fear of test. I had a lot of great teachers along the way that saw me struggling but kept pushing me. No one not even me ever knew i had a dyslexia until several years after high-school. If it were caught sooner i would have been much better prepared. I have self studied on how to overcome it My boss gets tickled that I am so very detailed oriented I catch the little things. Drives him nuts sometimes. But saves him. He has been sending me his work to check. Saying look this over let me know what I missed. I think my visual imagery mind is great on surveys but also a hindrance. I can look at a site and plot where control needs to be and say if you do this your closure will be x. If the others say let’s do it this way i guess that as well. Geometry strength of figure can make it so easy.
Dyslexia is a tough problem to overcome. I admire you for your success.
As a younger test taker, I did everything from the ground up. Read the problem, digest the givens and asked fors, fhen use your knowledge of processes to solve it.
When I started teaching, I learned “test-taking techniques” that eschewed read, understand, solve in favor of eliminate impossible answera and guess among what’s left. Problem is, without understanding, you can’t know what’s impossible.
I taught read, understand, solve. Now I did teach some calculator tricks that could be used if you’re really stumped, but I wanred students to know what they were doing.
I think that using practice problems as a study guide is superior to taking them as practice tests. As a study guide, they lead you to ancilliary topics rolled into each problem and develop the skills needed to put several conceprs together to solve a single problem. Time is not a problem if you know what you’re doing.
Anyway, enough about teaching and sueveying. You guys have work to do and I need a nap!
ignorant test takers, making a guess
In this case if I had no idea how to work the problem or was running out of time I would see that two of the answers involve 6 ft and two of the answers are to move in. Therefore the best guess is to move in 6 ft.
Doesn’t always work, but it’s a useful trick that I’m surprised test writers don’t avoid.
.Indeed, but note that the wording in the problem can be changed so that any of the answer choices is correct. That’s one way that test makers can make different versions of the same test and be assured that each tests the same material.
I’ve been gone from the classroom for 8 years now, but the test makers always kept up with techniques when I was teaching.
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