Utility Lines Through SRW Leveling Pad 1

[Mitchell Wilson]

I am a Landscape Contractor.

I have worked with the same engineer on three different VersaLok SRW. Each of these walls have had Utility Lines that ran directly through the leveling pad portion of the wall.

Each time I had the engineer come out and assess the situation. The first two times he advised me to pour concrete around the line after I sleeved it with schedule 40.

The last time he had me pour concrete solely around the sch 40 sleeve and then add crusher run on top of that concrete to continue the base course on out.

Is this common practice? I am a bit worried after going to events with other landscapers who do not recommend concrete and crusher being in the base course because they will settle at different rates which could lead to segmentation. Any advice is greatly appreciated.

 

[EireChch]

Can you draw a section?

I am confused, is Case 1 - pipe sleeved and concrete poured to desired level. and Case 2 is concrete poured to just over pipe and then aggregate above to desired level?

 

[Mitchell Wilson]

Let me know if these are visible and they help!

 

[MTNClimber]

We always recommend installing the concrete up to the bottom of the next block course. It's easier and alleviates the worry of differential settlement.

 

[EireChch]

yes I agree with MTN, gravel above the pipe will just promote block above to settle. Cant see it helping much with reducing stress on pipe

 

[Mitchell Wilson]

Does it alleviate the worry of differential settlement if the leveling course isn’t concrete and is a gravel base such as crusher run or 57 stone?

 

[MTNClimber]

Is the gravel base buried or is it above grade?

 

[Mitchell Wilson]

The bottom of the gravel base is buried 26” on one of the walls and about 16” on two of the other walls. Both bases are 8-10” thick.

 

[EireChch]

If the block are all resting on gravel or all resting on concrete then differential shouldn't be an issue. Its when you have some on gravel and some on concrete that you start having an issue

 

[MTNClimber]

I agree with EireChch.

Also, if the gravel on top of the concrete collar is buried then it’s less of a concern than if it was exposed. If it was exposed then it could unravel from under the block with time and cause settlement.

 

[Mitchell Wilson]

EireChch, that is what I have in all three scenarios. They are all gravel bases but utility lines were found directly running through each base. Which is why I am concerned. I took photos and documented everything. But I am frustrated because I got two pieces of advice and now I am coming to the understanding that it may be problematic.

So, now in two of them we have a 16” concrete slab poured and in one of them we have a little bit of concrete poured around a sleeve and then gravel on top of that.

Is this something I should be highly concerned about?

 

[MTNClimber]

How many block courses are on top? Are we talking about a small wall or a tall wall? How thick is the gravel on top of the concrete?

 

[Pinwards]

You might also want to look at what type of Utility it is and what the Frost Depth is in your area, to make sure it's not more shallow than required and potentially could freeze.

#

 

[Mitchell Wilson]

Gravel had to be at least 6” on top in order to do that. If it wasn’t then we poured up to the next course.

Wall when we put gravel over top of concrete was 3 ft so not a huge deal.

Walls when we poured concrete, one was 7 ft with a driveway on top the other was 3 ft with a deck on top.

Each wall was Versalok standard unit so 6” tall block.

They were gas lines.

 

[MTNClimber]

I wouldn’t worry too much. Sounds like worst case is you have to do a partial tear down and install some concrete if there is some settlement. Going forward I would avoid the situation by bringing the concrete up to the next block course.

 

[Mitchell Wilson]

MTNClimber- thank you for your response.

I will do that going forward.

It sounds like I will be okay with the two walls that I poured concrete up to existing course even though the base is gravel?

 

[MTNClimber]

They should be as that is the standard approach.

 

[EireChch]

Yes, this are small walls. Dont loose any sleep over it

 

[Mitchell Wilson]

MTNClimber and EireChch, thank you for your responses and for your time.It is greatly appreciated.