I need some help!!! I have been doing excavation for 15 years and have never done a job this big and would like some help figuring out cost per yard on a wetland job, most of the work can be done with scrapers, but the last two wet cells, the water table will be 5 feet above the bottom grade, the dirt has to be excavated (wet) and haul across the highway to be stockpiled, the wetland area itself is about 24 acres, you have to do all your own surveying and staking, and it has to be with in a 10th of a foot. Im just having a hard time figuring out a per yard figure since its going to be wet and has to be hauled. Anyone done this kinda work? If so what would you charge per yard to strip, stockpile, and place topsoil, excavate wetcells and haul off a minimum of 100,000 yrds of dirt and stockpile?:Banghead
Yair . . . sundanceexp . No way anyone could give you any meaningful advise from that project description . . . exept to bid it high as you can get. Plenty of folks on here do that kind of work but you need to know the country . . . cheapish scraper dirt can turn to expensive wiggle waggon dirt overnight for instance. What are the infiltration rates and soil type once you get below the water table . . . are you going to work it underwater with a hoe or pump it and try and work it dry? That highway would be an issue . . . how do you handle traffic control? Lots and lots of questions, I'm sure you get my drift. Cheers.
the soil is on the entire project underneath the topsoil is sand and gravel and im not sure how fast the infiltration rate is they dont have any info on that. the highway is low traffic but if i haul over fifty loads a day across it i have to have a flagger, im not sure if i can cross with my scrapers or if i have to haul it with trucks the stockpiled material then becomes my property after it has been stockpiled i think i will have to use an excavator because i dont really have anywhere to pump the water to, maybe to one of the other cells after they are built im thinking like $4per yard thats what i usually get but thats for cut and fill and grading jobs
You really need a definite plan how you are going to do this. Dewatering the site is one method, underwater excavation is another. You need to define in your bid a conditional qualifier as to the costs associated with each method which will be different. You can't just give them a flat rate per yard when the water, roadcrossing regs. and soil conditions are not specified. If they insist on a single price, quote the most expensive method and if you can do it cheaper then you win.
About the road crossing. It is usually cheaper to build a scraper crossing, and haul it across in the scrapers than it is to use trucks. Concrete or thick asphalt. Have an engineer look at the existing road and subgrade.
I also recommend that you think about this a bit. If you are going to use scrapers then make sure you leave enough frim material to support the trucks (be it 10 wheelers or ADTs). Don't forget that once you start driving over things, you will bring up the water. I have had my excavator start sinking just from the action of digging (wetlands restoration project). I would recommend that you do this when things are frozen. This may give you more room for error if things are getting too soft. IMO sand and gravel will allow water penetration rates to be very high. Shifting water from one cell to another probably will not work as the water will, most likely, leach back just as fast as you pump it. Furthermore you will need some very big, expensive pumps, and someone to babysit them. You best pray that nothing goes wrong with them or you will likely loose all productivity for the duration of the problem, and the time it takes to dry things back out. I would prefer to use an excavator to load trucks. I don't know how you are going to get to within a tenth without dewatering though. What is the reason for such tight tollerances on a wetlands restoration project anyway? Unfortunatley there is not usually very much money in these projects. IME they are usually government partnered/subsidised, private land owner projects.
Excavator with GPS running on mats if you have to... ADTs or top loaded ag pans with tracked tractors... don't waste time trying to dewater mass grading unless you absolutely have to, just use the GPS and dig it wet.