Mud Mess Jobsite

[chris the wrench]

We are building a few pole style covers on our property this year and with the warm winter(aka crappy skiing) I thought I would get a head start. About a month ago I cut a terrace, roughly 24'x24' feet into one of our gentle slopes. The cut side is probably 20-24" below the previous grade. When I did this the temps were constantly below freezing and the ground dug and moved really nicely. I had it pretty dang level. I piled extra high on the downhill side to allow for some compaction. Well today I decided to do a little touch up and get it closer to ready for putting post holes in. Welp that was a mistake. Tires sank to the belly of the tractor, and my once pretty dang close job site is an absolute cr@p show now. Mud everywhere, tractor tire trenches going every direction.

This will be a gravel floor when it's done.

What are my options to deal with the current mud mess:
Wait for constant warm/dry weather to naturally dry it?
Add some gravel/rock, but will that just add to my mess?
Lime?


Thoughts/suggestions, besides don't do that again!

 

[Rustyiron]

I think I might start building while you're dirt dries out and just touch up the grading when you can work the dirt.
Pretty spot there!

 

[LouNY]

Wait it out, adding rock or gravel will just mix in and raise the surface grade and it will never have any stability.
I have a large aversion to cut and fill it almost never gets compacted well enough and continually settles for 3-5 freeze thaw cycles.

 

[chris the wrench]

I have a large aversion to cut and fill it almost never gets compacted well enough and continually settles for 3-5 freeze thaw cycles.

I hear what you are saying. On the filled side there will be 3 posts, each set bout 24"-30" below the previous grade height. So even after compacting my gravel may settle some, but I think the structure shouldn't be affected and I can add more gravel as needed.

 

[4570Man]

If you have to proceed now digging that out and replacing with workable material is the only real solution. Waiting for it to dry is a lot easier.

 

[Alan W.]

Hard to tell from the pics but there appears to be a lot of organic matter in that soil.
You can never build a pad out of that material.
To build a pad that an engineer would sign off on I had to cut all the organic matter from the site then build the pad up with clay.
If you dont take the topsoil off the downhill side before you start building it up the fill can slip because it will not bind with the topsoil.
Have seen this occur many times.

 

[chris the wrench]

Hard to tell from the pics but there appears to be a lot of organic matter in that soil.

All the grass/brush/roots were scalped before the original digging, anything thats there now is from stuff that blew in or tracked in.

But I hear what you are saying. Our snow load automatically qualifies us for having to have an engineer involved for even the smallest carport.

 

[Alan W.]

I think the main problem was the soil wasn’t or wouldn’t compact on the initial fill.
I haven’t done any commercial work in a few years. To get good compaction with smaller equipment you need to spread no more than a 8 to 10 inch lift of fill then with a full bucket run back and forth compacting that layer before adding the next.
I did this 40’ x 50’ pad for my neighbor this year. The fill area goes from 6” to 3’. The clay was barely damp enough to get compaction. I thought I was going to need to wet it some.
But it turned out well.

 

[ponytug]

@chris the wrench

How far down is rock? Also how far down is the frost line, and were you planning on putting your (concrete?) piers in below the frost line? Given that the site is on a slope, I would want the piers pretty far into native soil, especially given your snow loads...

Given the slope in the photo, I would strongly encourage you to plan on a swale and an impermeable membrane, or even a concrete footing on the uphill side to keep rain and melting snow from seeping in. Since you already know that the black soil you have liquified with water, I think that it would be great preventative medicine to do a fair bit to keep it from ever getting wet in the future.

My personal preference would be to dig it out and put rock / gravel / fines down in compacted layers. Your soil is undoubtedly different, but I have a similar looking soil that loses all cohesiveness when wet. Either you don't build on top, or you keep it from ever getting wet.

All the best,

Peter

 

[chris the wrench]

How far down is rock? Also how far down is the frost line, and were you planning on putting your (concrete?) piers in below the frost line? Given that the site is on a slope, I would want the piers pretty far into native soil, especially given your snow loads...

Frost line is 24”, piers will be 48”(I believe, but I have not gotten final engineering drawings). So on the filled side they would still be 24-30” below the native grade.