site regrading question 2

[delagina]

I have 350x150 industrial site. Site will be located open field industrial site.
Natural grade slope of the site is 5%. I have to re-grade it to 2%. The issue is I'm coming up with a huge net cut (7500 cu yd) and also the fill height near the existing road is 9 feet. The existing road doesn't have any ditch.

I can play with these numbers, if want net volume cut reduced I have to increase fill height near the existing road.

Is there an acceptable ballpark number for both fill height and net volume cut for this site?

 

[oldestguy]

The volume of material from the cut usually "shrinks" by the time it gets to the fill. I'd check with your state highway or similar design group and inform them of your situation. Their experienced engineers may offer some useful advice. That number depends on several variables, such as haul distance, soil type, etc. The degree of compaction you want also depends on what you will sit there and the desirable bearing capacity. A local geotech also may have sufficient earthwork experience to advise.

 

[delagina]

i just realized the slope 3:1 to existing road. this wont work, i will have a big volume cut here.

 

[beej67]

Since you appear to be relatively green, here's generally how it works. You take that 2% slope line in your cross section sketch, and you slide it up or down until your site balances. When you slide it up, it shifts left, when you slide it down, it shifts right. On an easy site like a pad (as you have) there's no reason to have any net haul-in or haul-off. If you know your current net cut or fill, you should be able to relatively easily estimate what new pad elevation will appropriately spoil that, and nail down a balanced site pretty closely with your 2nd iteration at grading.



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[delagina]

@bee67, I can easily have zero net cut/fill. civil 3d has options to do that.

the issue with that is i will have a very high fill height near the existing road.
from the existing road, my access road is 10% slope maximum and that will be the lowest point of site.

if the site is 100' from existing road, then i can balance the cut and fill easily.

 

[Ron]

If this is an industrial site, you'll likely have large trucks moving in and out. You do not want a significant grade at the the roadway for a variety of reasons, not the least of which is trailer dollies bottoming out at the road slope transition.

 

[delagina]

yes, industrial site. i will use 10% slope access road.
even with 10% slope, i'm still getting a very huge volume cut.
if i use less than 10% slope, i'd have a bigger cut volume.

 

[oldestguy]

If the site is large enough, the access road can be at flatter slopes, placed in its own valley so to speak.

 

[beej67]

Just make the access road longer. Have it wrap around the site until it catches grade.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[delagina]

What are the issues if I decide to have 7500 cu yd cut volume instead? aside from cost hauling the soil out.

I don't think client would want the truck going in and out the site to go around but I can suggest that.

 

[cvg]

well, the issue is that your client is going to be unhappy if you can't find a way to either waste the material on site or eliminate in some other way. haul off is the worst option. also remember that you will be hauling material that has swelled. the haul volume will be more like 9,000 cubic yards

 

[civilman72]

To answer the OPs original question, there is generally no limit to height of proposed fill next to a road, so long as that fill is placed in the property and not in the road right-of-way.

I agree with most other comments, sounds like your second option is to raise the fill to balance the site and use a longer access road. You can show your client both options and let them decide if they want to pay to haul off the extra material in order to shorten the access road length. It's generally not your job as an engineer to make these decisions, but it is your job to present all the feasible options to your client. You also should be prepared to present estimated costs for both options, which means you need to be knowledgeable about local unit prices for earthwork, asphalt, etc.

 

[beej67]

What are the issues if I decide to have 7500 cu yd cut volume instead? aside from cost hauling the soil out.

Nothing but the haul off as far as I'm aware.

Just so you're clear, at 12cy per truck you're talking about 625 dump trucks worth of material you want to haul off. Guessing a five minute cycle time that's 52 working hours of excavation. Plus you have to find a place to landfill it.

If there's another major fill project nearby you can sell the dirt to, it might be a real benefit. If not, I'd try to balance the site.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[delagina]

thanks for the help. I'd give that option to client.