I have searched the forum and realize there isn't one thread/place where all this information is provided. I think it would be useful for the younger generation and seasoned veterans as well to have a single reference source for such matters as Civil Engineering Calculations, Formulas and Site Layout Techniques. Your posts could include shortcuts, diagrams, links, formulas etc. This gives all of us much needed information without having to search the earth to find it. If anyone knows of a decent Android or iOS app for smartphones, that information would be very valuable since we all seem to be moving in that direction. An example: Calculating cubic yards of fill; Length x Width x Height or Depth / 27 = cubic yards, 20'x30'x6" would be 20x30x.5=300 cubic feet divided by 27=11.11 cubic yards. Where (L)ength times (W)idth times (H)eight provides cubic feet you then divide the sum by 27 to obtain cubic yards. There are swell and shrinkage matters to consider for different types of material which also need to be included in the calculations to obtain the most accurate number. As we all are aware, dirt is not always cheap and it is the best practice to purchase the correct amount, not too much and definitely, not enough. So, you get my drift. There are long drawn-out ways to figure such things and the easy shortcuts that we use daily. If we can get them all in one place, we all benefit. Do you know how to use a grade rod and transit? Do you know how to establish a radius with and without a Surveyor's Radius Point (RD)?
I agree, this would be nice. I could also see a liability disaster:beatsme I grew up in this business but have no college education. A lot of things were common sense ( to me ) but years ago I decided to learn more. I borrowed the course books from a friend ( who graduated from OU const sciences ) and things were clearer ,not to mention the piece of mind I had . No I don't have the degree but along with the experience from the field I feel better about how I do business. I love to learn more about this profession when I can , so could see where this would be helpfull to me and others. We must always do our due diligence to provide our customers with professional service. My point being , there are many ways to learn this trade and this forum has been a wealth of knowledge from GOOD people ! 15 years in this business and I still don't know it all :idontgetit
Could you elaborate on what you mean by this statement? I do have a college degree in construction management but not civil engineering, I can't see where calculations, formulas and site layout techniques if learned and applied correctly would lend to liability issues. We are only applying the information provided to us on civil drawings/blueprints. It's when we get it wrong is when liability could be an issue. Having said that, I am not sure what you meant.
I think he just meant if someone goes out into the workplace and misuses information from this thread causing a catastrophe financial or otherwise the misuser could try and place liability on the party who originally posted the information. That said, I think this is a cool idea and I will preface my statements by saying USE THESE STATEMENTS AT YOUR OWN RISK!!! Finding percentage of slope: (Elevation Change/By Run)X100= Percentage of Slope (100' Long Slope with 5 Feet of Slope 5/100=0.05 (or 5 hundreths... each hundreth being a percent) X100=5. Another handy rule of thumb that I like to use: 1 acre 1 foot deep (cut or fill) equals +/- 1600 CY... Actual math is 43560/27=1613.4074
Ha, I like your answer and think it will work, we'll just add disclaimers. However, we all must learn how to use a grade rod and transit, I believe most of us know how swing a radius too. But I understand competely, this is no longer a world without cost or consequence, disclaimers it shall be. !!FELLOW MEMBERS, READ AND USE THE FOLLOWING INFORMATION AT YOUR OWN RISK!!
Nail on the head:exactly. C.Y.A ! :thumbsup. Don't want good people to be thrown under the bus due to that one village idiot! :duh:duh
Well then, we'll just have to keep a close eye out for the "village idiot". We surely don't want to find ourselves under the bus for any reason.
I suppose the idea of this thread was good in theory, since no one really seems interested in adding I have to assume the application is a bust. Exactly how is it that a thread author deletes a thread? Absolutely futile!
Patience grasshopper . Give it time. Y'all have already posted things that some one WILL find helpful.
Once posted on HEF and after the allowed user edit time, it's here forever.:cool2 We have a policy to not delete threads or posts unless there is a special circumstance. Be patient with the replies, more will come. On topic of the thread, I too have a degree in Building Science. I choose the management side over the civil/design side of the business and haven't regretted it. The dirt calculation and swell factors have been discussed in depth on the board in multiple threads. As far as layout techniques here's my take on that - Engineers and surveyors get paid and paid well, to design and layout jobs. Contractors are paid and paid poorly here-lately, to construct the project. I want the surveyor to layout the job so he takes on that liability. I want the Engineer to design the job where it works, even if I could fix it in the field. For example, I am currently negotiating the sitework for a small restaurant. Grading plan had water holding between the drive-through and an existing retainer wall. On paper, I could have gotten the water to drain around the dumpster pad but I told the owner to send it back to the civil. The result of this was the addition of 200 LF of 10" ADS and two catch basins... Now I could have told the owner that I could take care of it but what if by some unforeseen circumstance I couldn't, the parking lot was in and the water wasn't draining? It would be my arse inside the fryer.... ointhead Now I'll get off my :soapbox on the topic of liability and see what kind of tricks I can learn.
Maybe , just maybe the others think like I do, that if a knot head like me knows something everyone else does too. That being said from day one when I started checking grade for my Dad in the early 60's I've carried a peep sight (what others called a hand level) til the day I retired, it was invaluable for spot checking grades. Also how we V'd off stakes to offset them out of the way or if I had to bury something and needed to find it later on. These are things that are so out of date they get laughed at...........but they work, now the jobs are pretty much left to lasers and GPS......
Lol! That sounds like my child hood ! I still carry a hand level and old David White transit with me, along side the laser. Funny thing, the transit never needs batteries Never had a strobe light screw with it either! :Banghead
I have a demo formula that works pretty well for residential and light commercial type structures. Basically it's this: I copied from my Excel spreadsheet and posted it here, sorry for the small pic I am still figuring out how to use my Mac. If you set the cells up to automatically calculate, it makes producing an estimate easy. The "Factor" in the calculation of how many cans needed pertains to the different things you run across doing this type of demo like household contents, excess brick or stone, etc. One can plug in the can rate, equipment rate and hours, overhead and profit to determine a cost. You can also adjust the profit and overhead percentages to your rates.
I've gotten pretty good at estimating how many loads to take out etc just by looking at it, i usually get right within 1-3 loads
Good, Glad to see there's finally some interest in this thread and topic. I am not wanting to relieve Civil Engineers and Surveyors of their responsibilities but there are those times when we do work that we need to know basic techniques. That was my intent with this thread, one place to find good info so we don't look like fools when we're asked questions. I am a firm believer in a grade rod and transit, I know how to swing a radius with or without an RD, I wish I could find a way to demonstrate some techniques in here but I don't think HEF and AutoCad are compatible. Having said this, let's keep it going and keep the tips coming...
May be old school but this is how I grade for curb and gutter: Usually the surveyors lay out 4' off sets with grade hubs. All you need is a wooden folding engineers rule and a 4' level - I have graded a few miles of curb and gutter this way. Set one end of the level on the hub, get it level of course and use the engineers rule to determine the amount of cut or fill. As conditions change on site, you often have to switch which side you are measuring to - if the hub is lower than the grade place the level on the dirt and measure to the hub. It works quicker with a grade checker but I have done it checking my on grade as I go. I usually request the surveyors to give off sets and hubs 20'-25' on center. Also double check with the surveyor which sub-grade he lays out to - curb or asphalt. Had this issue on the last bit of street we put in. It was a short street, only 250' long. The surveyor laid out sub-grade to curb sub-grade, which was fine by me as our part of the contract only included grading. The curb was 12" tall, 6" at the face of asphalt and the paving section was 11", so once curb was slip formed I would need to cut 5" out to asphalt sub-grade. The curbing guy thought the surveyor laid out the asphalt sub-grade, so he begins to add back 5" of dirt and compacting it under where the curb is going. After about an hour or so of finger pointing and another hour of the curb guy removing the dirt he put in, the curb was slipped. The confusion was between the surveyor and the curb guy - it wasn't my problem since the developer was handling the curb and paving directly in order to save money.:cool2
We did it about the same only we would measure up on the guard lath by the hub and mark up to an even number 2' - 3' or whatever (has to be the same from side to side at each station) that saved us from having to bend over so much and could also string line from those marks. The grade man would do this then if he wasn't around I could check it myself and if I found an error in his grade setting I would paint the stake a nice orange color so he knew where he needed to recheck his math.
Typically in our area the surveyors use 12" grade stakes and set hubs for grade reference. Sometimes I may off-set the hub and use a longer 18-24" stake to mark it. Here is a typical stake and grade hub that we use, the hub is next to the string line pin. This off-set is 3' off the back of curb and gives top of curb (T/C) -
I recently started a website that is intended to help people with these and other questions about civil construction. I will be doing a post on "grade setting/checking" soon along with other interesting topics. www.terrasmooth.com
Great site, made my favorites list.
I started this thread with the hopes of seeing some more interest. So, I'd like to bring it back to life if I may? Here's a new topic of discussion; When running mainline water pipe and you have to offset either vertically to clear a drainage pipe or horizontally to clear a liftstation as examples, does anyone know the calculation? Yes, you could build the offset as you're digging but it's much easier to assemble it on the hill then lower it in the trench with the excavator. Three of us struggled with the formula but in the end we got it right and all is well. Again, anyone know the quick formula for pipe lengths?
This is kind of a confusing question SeaMac. I'm not sure what you mean unless you are talking about using pythagarous(sp) theorem? Can't type it out right but it's the a squared + b squared = c squared formula.
Holy Crap, I think my learning curve must be straight up. All you old timers have forgotten more stuff about grading than I'll probably get a chance to learn. I watched a video on reading grading stakes on youtube and I'm not sure if I'm more or less confused...lol. I can see now I should have pursued civil engineering instead of business management, then maybe some summer internship at a surveying outfit. Offset this, and grade hub that...whew, I've got a lot to learn. But I sure do want to learn it. I think I would prefer the old school approach first, then the new school. I'm scheduled to spend a couple of weeks with our G.I.S. department shooting leaks and taps and and a new gravity sewer project. Looking forward to some hands on with some very expensive and accurate mapping equipment. Just wish it was a little more aligned with proper surveying. Thanks SeaMac, and other contributors, for a thread like this, I've already picked up some useful info. -Loco
First of all I have the utmost respect for a good Civil Engineer that knows their stuff and is part of the project team. However just going through the courses and obtaining a degree may not teach you much, I prefer the field to the classroom as far as learning goes. Funny, true story - The GC's son was trying to establish FFE (finish floor elevation) for a slab they were getting ready to pour on a job I was finishing up. There is a bench mark established by the surveyors with an elevation on the site. He had his laser set up, grade rod and target in hand. This civil engineer couldn't figure out how to set FFE from a benchmark with a laser set up.:cool2 In a few minutes I had his FFE set on the grade rod. Quote - "I have had a ton of math but I just can't figure this out".
Austin M, Yes it is confusing, trust me three of us struggled for nearly 45 minutes trying to figure it out. True, there are engineering theorems and calculations there's also the simpler way we do things in the field. As it pertained to "our struggle" we had a conflict with 60" RCP and 12" C900 water main where we needed to offset the H2O down across and below the RCP then back up and level to elevation, a 4-bend saddle if you will. One leg of the saddle was at a different elevation than the other and we needed to keep both legs at 45*, clearly they had to be different lengths and we wanted to build it on the hill for time saving purposes. Oddly the AHJ allowed a C900 water main to run under 60" RCP directly in the roadway, one would think it should have been DIP but......we do what the plans show even though this municipallity doesn't have the equipment to dig at the depth should something go wrong down the road.
Haha! I just had to do one of those last week. Installing 8" C900 and had to go under 21" SDR 35 sanitary sewer main. We did one the way the plan showed, and fought that the whole way as we had groundwater coming in the hole as fast as we could pump it. We actually had to do two of them and the first one we built as plan, I.E., assembled the 45's in the hole and vowed that when we did the next one we were going to build it up top and lower the whole peice down. As it turns out, when we got close to the 2nd crossing, we double checked elevation and were able to maintain the 2' of clearance by deflection so we only had to put 2 45's on the uphill side to bring it back up. We did actually build that part on top but it was pretty easy as we only had to measure the pipe between the 45's on the one side.
I was never that flash at maths, can do the basics but not the more advanced stuff, for example I can work out cubic volume for all things square but rounds confuse me. For example how much concrete to order for 10 post holes, 450mm wide by 1200mm deep. Volume equals pi (3.14) times radius squared times height times number of holes, 3.14 x .225m x .225m x 1.2m x 10 = 1.91 cubic meters Of course you can use an online calculator http://www.calculator.net/concrete-calculator.html
Wait a minute here, your Inspectors will allow deflection? Not so 'round here, they're beyond anal when it comes to deflection. They want it straight, plumb and level, they'll even whip out a deflection gauge to keep us honest. Basically, they're a bunch of kids fresh out of college trying to make names for themselves and we're unfortunately on the receiving end too many times. It would be unheard of for them allow clearance via deflection...
Yes, if it's a reasonable amount. They won't let you deflect pressurized water lines if necessary? It actually helped us both out as we didn't have to struggle in a mudhole and it saved them some a little money on fittings. In this case, I was more than happy to yield a couple 45's as opposed to 25 MH's trying to thrust block 2 of them. Which is what happened on the first crossing.
Thrust blocks, seriously? Wow, I haven't heard that term used in new construction in over 15 years, nowadays 'round here it's all bell restraints and nothing but. There's a pipe manufacturer -name fails me at the moment- that uses a locking type gasket where now even bell restraints aren't required anymore. We used to pour thrust blocks years ago now we bolt on bell restraints in the future it seems we'll just slip a spigot into a locking-gasket bell and be done with it. It appears there will come a day when Operators sit in a trailer and play video games and the pipe will seemingly lay itself. I'm not so sure I will welcome that day either.
Yes we used thrust blocks. We are using MJ gaskets and flanges but if you were to use Mega-Lugs on your valves and fittings, you wouldn't have to thrust them. Mega-Lugs are way easier to use but they are quite a bit more expensive(as I'm sure you know) so in an attempt to keep cost down because we figured our competitors would bid with MJ fittings, that's what we went with too on this particular job. All jobs up here are designed with thrust blocks so you also have to ask the engineer to allow Mega-Lugs. I haven't met an engineer yet that won't let you use them if you ask though.
AustinM, Yeah man, Megalugs are an absolute timesaver. What gets me though is most people don't know that the red Megalug can be used for DIP and C900 so long as you remove the washer before use on DIP. Most contractors 'round keep buying black Megalugs -DIP only- and red, seems to me one could save even more by purchasing one that does more. I've been hearing rumors that a few of the cordless tool manufacturers will be releasing IP56 (water/dust intrusion resistant) rated drills and impact wrenches which will speed up Megalug installation even more. Double-shot wrenches and basic ratchet/socket is fine so long as you keep 'em clean in a bucket of water but cordless will certainly be welcome.
CM1995: I have seen curb and gutter graded the way you described. Folding engineers rule and a level. Works pretty slick. Hendrik: I agree with you on the calculating the area of a circle. It's easy to make a mistake with that one. I've screwed that up a couple times, by using the whole diameter of the circle rather than cutting it in half for the radius. Thankfully caught the errors before it cost me though. Get lucky sometimes. Other formulas I use quite a bit: Tons of asphalt: volume in CF x 150 lbs/cf divided by 2000 Tons of base: volume in CF x 140 lbs/cf divided by 2000 the lb/cf weight of base will vary from pit to pit and job to job but 140 is usually a good number to use if you need a quick quantity estimate. I have used the asphalt weight all of my career so far and that stays pretty constant. Another asphalt formula is 110 lbs/sy/inch. So if you know you are laying 4 total inches of asphalt it's 4 times 110=440. 440 times however many SY you are paving divided by 2000. I always use the 150 lbs/cf because it's a little more accurate, but this one works too.
Not sure how I missed this thread in July but I think its a great idea! I started in this business with a skid steer, then a mounted backhoe and now a mini ex and hope to keep growing. This first time I had to bid rock for a project it was a headache. Now I figure it in yards, and then convert to tons required.... Blows some peoples minds when you figure rock required with a basic calculator in just a few minutes. for example gravel pad 100'x50' 6" deep: 100x50=5000x 0.5(for half a foot)= 2500 cubic feet/27=92.59 yards x2500 (pounds per yd average from my local quarry)=231481/2000=115 tons of rock. Maybe somebody has a short cut but thats my method. It confuses the he!! out of my wife to watch me do it. I have a laser but have never learned how to properly use one. I measure everything and plot it on paper or in my head to determine cut and fill. If somebody could explain the proper process I'd love to hear it. I've always been intrigued by how to lay out a basement to get the right floor height. I have turned down a few because I have no clue how to figure it and lay it out.... Just a few ideas. I'm here to learn and this forum has been a HUGE education for me in this business so fire away and I'll try to soak it all up. John
Yeah it's easy to make mistakes, always a good idea to write things down, including the formulas used. Writing stuff down is also handy for when things don't work out because you have a history and may be able to find out where things went wrong, one decimal place in the wrong spot can be a disaster
That's how I calculate a clean rock. Convert from CY to tons exactly the same way. As far as using a laser: I use paper, (or my hand) to write on to calculate cut and fill. Also have a calculator, but most times I forget it in my pickup and don't feel like walking 200 ft to get it so I just do it on paper. This is just a personal thing, but I prefer to use an instrument and a have another person holding the grade rod as opposed to a laser. Don't get me wrong, I haven't been burned by a laser yet but I have seen them do weird things. For instance, if someone has their strobe light on their pickup working in the vicinity, it will screw up the sensor on the rod. Just a mind and a trust issue for me, but they do work. Just a personal preference, I guess. What's funny to me is that I can make up to 25 calculations a day with an instrument, do it fairly quickly with everything working out, then on one late in the afternoon get mixed up with cut and fill and add when you should have subtracted, or forget for some reason to add the thickness of RCP to the a flow line calculation or something else, (even though you have already done it several times earlier in the day) and cost yourself 10 minutes of going over it in your head, asking someone else to shoot it and compare numbers, etc. LOL
Couldn't agree more. While working R&D for that 2 wheeled conveyance company, I worked with dozens of newly minted wheel inventors. There were exceptions however. One man, K. Peters was a consummate engineer, machinist, mechanic and balls to the wall rider. He was experienced and confident. But not so confident that he didn't listen to the informed perspective of others. He was an excellent active listener and always treated everyone respectfully. He had a way of disagreeing with you that didn't make you feel like an idiot, even if you might have deserved it. I tried to model myself after his example while there and if the opportunity to further my education presents itself in this field I love so much, then I will try to model the same behavior.
Thrust Block (we call em Kickers) and Deflection (we call it bending in small doses and a Presidential Solution when it's scary) now this I can relate to. I guess my outfit it a bit seat of the pants...hahaha, oh yeah, might need to get some kevlar underpants if it gets any more "improvisational". I hope I don't sound like a moron, but I really wish we were a bit more "technical". I feel like I'm going backwards in time......
Not at all. I just came off hiatus from HEF after a not being able to discuss a thread that was close to my heart and now am finding a many good discussions on grade checking that I am passionate about. Calculations and grading techniques that are necessary to making money or making money for your employer. At one time I asked why HEF didn't have a grade checking forum but maybe it will get seen more in the General Industry Questions forum. If you look in the Equipment for Sale forum, I put a book in there that covers a lot of the calculations and techniques used in everyday grade checking as well as a new system for checking slopes. The only way to assure you are keeping your quantities in line with your estimates is by having good grade checking skills to make sure you are only moving what is necessary. Yardage = $$$$$ Knowing what you are doing in the field is as important as knowing what you are doing in the office.