Here is a GREAT tip to grade your streets in a way that will help you handle your wet utility spoils and, in turn, can save you money! During the rough grading process of your project, have your grader rough in a “gut section” within the streets during his operations!
What is a “Gut Section”?
One thing a good developer is always thinking when putting a budget together or when contracting work is, “what will I be doing with the spoils?”. And now that you’re thinking ahead, you can leave your street subgrade elevation lower than needed to accommodate the wet utility spoils. This is the “GUT SECTION”. Notice that this is very similar to leaving a “disposal hole” within your site. (Just as we discussed in our last post “The Benefits of Having an Import Site“).
Typically the minimum street subgrade cut by the grader is about 12″ from top of future curb. And the gut section is cut about 6″ beyond that (see drawing examples shown above). However, the 6″ can fluctuate depending on the amount of wet utilities you anticipate to pull out.
How the Process Works
Usually your rough grader will rough grade the streets during his operation. Afterwards, your wet utility sub will then mobilize to excavate and install their utilities within the street. At the same time, the sub will be stockpiling their dirt spoils off to the side (usually behind Right-of-Way). After they complete the backfill for their utilities, they will then transport their spoils off-site.
HOWEVER, if your grader leaves a gut section within the subgrade of the street then the wet utility spoils can go here after he is done backfilling! Thus saving you the extra money from having to haul it off instead!
(PLEASE NOTE: you most likely will not be able to eliminate ALL export of the wet utility spoils, but by having a gut section you will be able to reduce the amount significantly).
Leave a Bench!
You must remember, though, that you will have to leave a bench for the curb and gutter to sit on. What this means is your gut section won’t be able to extend the entire width of the street. (See exhibit below). The reason this bench is necessary is because you need to allow a platform with enough room for the curb machine to sit on without falling off as it forms the curb and gutter.
Your Rough Grader Returns!
After your wet utility sub has completed their operations, your rough grader will come back to rebalance the streets (the gut section) with the newly placed wet utility spoils. He will grade the street subgrade to +/-.20’ and haul off any excess dirt. (Your paving subcontractor can also do this).
Time for Paving!
Now that your street subgrade is graded and all the remaining wet utility spoils are gone, your street improvements subcontractor can now mobilize and finally install the curb & gutter followed by the paving!
