Working on a bid, the plans have 42835 C.Y. raw cut 28365 C.Y. compacted fill, supposed to be a balanced job. 42835 - 28365 = 14470 more cut than fill. Find the percentage by dividing 14470 by 42835 = 0.34 or 34% shrinkage. Engineer says it's 20% :beatsme. Can't convince the customer or the engineer Am I wrong?
I guess that I look at things a little different. A lot depends of the fill material as you well know. Here with this type of clay I plan on moving 1.3 to 1.4cy of material to get 1.0 cy compacted fill. I have worked material that had a cut to fill ratio of 1.1cy to 1.0 fill. Those were steak and potatoe jobs. 28365 yds of compacted fill would require 39711cy of material at 40% shrinkage. Your example has you moving at a rate of 1.51cy of cut to get 1.0cy of compacted fill. Just a little over 51% shrinkage. That would bee some very loose material to shrink that much. If the Engineer is claiming a cut to fill loss of 20% it should work out at 28365 x 1.2cy = 34038cy moved. At least that is how I have always figured it.
You are right and I am wrong, I should have divided the difference by the fill yardage not the cut. 14470 divided by 28365 = 51% Thank U my mistake. The engineer is calling it 20% he is even farther off than I was thinking.
try simplifing the numbers for them maybe. like use 42 & 28, or 40 & 25, it should be plainly obvious.
You were right the first time. If 42,385 shrinks by 51%, you're left with 49% of the original volume. 49% of 42,385 = 20,768. 28,365 is 66% of 42,385. This means that shrinkage is 34%...no?:beatsme
D3B is right, there is 14470 cy more cut than fill so what percentage is 14470 of the fill which is 28365cy 14470 divide by 28365 = 51% I was dividing by the cut (wrong) Got some of ya thinkin anyway LOL
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Hey Dpete, just curious what does that size job go for per yard out there. That looks like a typical size job that i do here. Im with you, i dont agree with your engineer, however i dont know your soils. Here we figure 20% but that would make ur fill be 34268.
When things were hot here we had no problem getting $2.50 -$2.60 per cut yard that included everything, stripping, prep, water, compaction, finishing, equipment transport, ripping, dirt hauling, I'm going to be in the $2.10-$2.20 range, probably be lucky to get $2.00 now it's so dead . Lots of loballers out there chomping at the bit to wear their equipment out for nothing.
Projects too cheap Not to hi-jack your thread DPete, I had 4 contracts left over from 2009, but I am about to start a project that is about 125 miles from home. I only put a number on it because it is at a large lake. Thought it might be nice to work and fish. Another project that was 30 miles from that project bid two weeks ago. Thinking that it was in the neighbor hood, I looked at it and did not bid due to complications. I roughed a bid of 400K. It had 3 bidders at 207K, 385K, & 441K. I feel sorry for the low bidder. He never looked very close at the specs. Close to home here last week a nice dirt job bid, low was 320K, the next 2 were 482K & 486K. I guessed the job at 490K, but did not bid when I saw the low-baller at the pre-bid. He is a Farmer with a large family so no Davis-Bacon for him. Tough to compete with him. Hope you get the job.