Estimating truck yardage to placed yardage 3

[Dooley]

I am currently putting together a proposal for an owner that is specifying payment of un-screened topsoil 8" thick by truck loads.The material will be hauled in 30 ton off-road trucks(I am allowing 20 CY per load estimated),dumped in a pile,spread, and walked in by a dozer.The areas to be covered are dry sand slopes averaging a 3:1 slope.Given the fill material and the base over which it will be spread,am I safe assuming 30% loss due to shrinkage or compaction?

 

[cbosy]

What are the soil properties of the topsoil? The Excavation Handbook by Church has an excellent table giving shrink/swell values for various materials. It lists 26% shrinkage for "topsoil."

 

[DRC1]

How are you buying the topsoil? You should sell it by the same measure. If the soil is somewhat wet you are probably around 100 #/Cu. Ft. If it does thats 22 yds per truck. Unless you expect a lot of loss or you are really going to walk it in 30 % seems high I would estimate (although I am not familar with your project) around 20%. Usually topsoil is not well compacted.

 

[Dooley]

Maybe I should clarify a bit more. The material is probably more a sandy loam. It is sitting in a couple stockpiles located around the project.My costs would be to load, haul, and spread it to the 8" finished depth.As the owner will pay by truck cubic yard I am trying to figure a rate to apply.I am accustomed to working material that is more easily quantified (aggregates,clay,etc.) and this has me a little at a loss.

 

[KRSServices]

The solution to your problem is not to apply a shrinkage factor at all, in fact...throw those numbers and concepts out the window. The reason is that an applied factor will either favour the Owner (hauler loses money and files a claim or the hauler is happy because he makes more money than he should.

Weigh the material. Pay the hauling on a ton basis or a ton/mile. Your material is going to change, and your fluff factors will not be accurate. The truck will not ever haul an accurate quantity (ie 25 yards). some loads will be greater, some loads will be less, depending on who is loading. If the hauler is loading, the loads will surely be a little less. I have years of analysis and statistics to back up my assertions and also have been able to save considerable dollars using my contracts specifying weight versus measured truck box (with fluff, shrinkage or any other factor that can be applied). It is absolutely fair to all parties because a ton, is a ton, is a ton. It will never change, never shrink, never get fluffy. Call me and I can email you some suggested wording and verification clauses.

KRS Services

http://www.krs-services.com

 

[cvg]

measurement by the ton is good, however two things to consider

you need a scale to weigh the trucks. you also need to tare each truck before loading. unless it is a large job, do you want to pay for the scale and operator/inspector to record the weights of each truck?

If it rains, you will be paying a lot of money to haul water. make sure the soil has dried out prior to importing

 

[KRSServices]

Very good points cvg.

Firstly regarding the scale. For the past 10 years now, or so, many scale devices have been incorporated onto the loaders themselves, particularly loaders involved in crushing or gravel operations. What I used to do for hauling contracts was specify the loader scale, calibration and weight of the soil/ton or yard (or m3). Then the successful hauler would verify and agree to the number. The verification process took into account the truck tare and and scale calibration. It usually took three to five truck loads to be verified at a highway scale or certified scale to come up with an averaged unit. From then onward, the loader scale was used and calibrated from time to tim with big contracts - hauling 300,000 ton or more.

The best thing was that the contractor was in agreement eith the process, as usually it was his loader scale. And since it was calibrated, there were usually not any issues. For the issue of susceptibility to moisture...simply re calibrate to determine changes. ALso, I incorped some clauses challenge clauses wherein if the calibration was out....there were significant penalties...so it kept the contractor honest.

KRS Services

http://www.krs-services.com

 

[mabn]

If you can measure strut pressures on the trucks before and after loading, some sort of sensor tied to the ECM and the ability to download or monitor the values going in, you should be able to get a pretty accurate weight measurement. It would be nice if these low cost sensors were an industry standard, and all haulers were required to calibrate to a scale every six months or so.

Also, a tonne isn't a ton(long) isn't a ton(short)....


Mabn

 

[JPatten]

The loader you use will have a certain cubic yard bucket on it so just figure how many buckets it takes to fill the truck. Not every bucket load will be the same but in the end it will probably even out. Load one truck and have the operator pay attention to each bucket and have him/her try and keep the buckets consistent. That way you know how many cubic yards of material you use without needing to know the weight.

 

[KRSServices]

JPatton,

The point you raised is precisely the principal as to why I had to go to weights. Consider this, I managed over 100,000 yards of (road crush, cold mix, and 1" crush) aggregates every year, and the haulers were paid by the load. Our loader bucket capacity was 5.5 yards/bucket.

To load a 20 yard wagon took 2.75 to 3 buckets. From the weight tickets, 2.5 loads was a little under 20 yards, 2.75 was about 20 yards and 3 was well over the allowed yardage in the wagon (heaping). By that math, the haulers were making good money because they were only hauling about 15 to 17 (fluffed) yards and getting paid for 20. The major headache was reconciling the initial volume of the spoilpile and the volume hauled...the fluff factor always changed and since the new system was adopted the numbers reconcile and balance.

When I introduced the loader scale, they were then paid by the load and no...even after a good rain soaking, the weight of the material by volume did not change noticably.

KRS Services

http://www.krs-services.com

 

[JPatten]

KRSServices,

I can understand your reasons for going to scales since you are dealing in such large quantities and if I was in your situation I would probably do the same.

Since Dooley is the loader, hauler, and spreader and since he is not paying for the material itself wouldn't the bucket method be close enough to calculate a cost to charge the owner?

 

[Chainman57]

Dooley, I have been reading this thread after advice from an associate in the industry because I have a similar problem. Mine may be more costly because it is happening at payment time and the owners are trying to change the rules. My project was bid, and the contract was signed,with payment based on TCY just as the project to which you refer. My foreman takes meticulous notes and every load is accounted for in the dailies and a log book he kept.I had what I call a silty, sandy, loam to spread, till 12" thick, and walk in with a dozer.( I'm guessing you are talking about wetland reclamation)The owner had mentioned early in the project that we should change the method of quantifying units placed but never pursued the matter until now.He wants to pay on a SF price but doesnt want to pay for any compaction.I want my money now as we all do so I am trying to come up with some reasonable information to provide backup without getting lawyers,other engineers,etc. involved. Ironically, when I estimated this project,I used 30 % as a best guess estimate and my load count has come very close to that figure.If some of you have other references available that would be appreciated by me very much. Otherwise Dooley, protect yourself.

 

[KRSServices]

Chairman,

Since you accounted for shrinkage, even estimated and the contract signed, unless there is a clause indicating the owner can specify the payment (as an SF from the bid unit, which included compaction) the owner may not have much recourse to demand another methodology of payment.

If the measurement and payment clauses are specific, that is how you are to be paid.

Good luck to you. I would be interested in hearing as to how it shakes out.

KRS Services

http://www.krs-services.com