Sheet Pile wall with segmental block facing

[fargofarmer]

I designed a SR wall recently. It is approximately 18 feet tall and 1000 feet long. The wall supports trafic load and has a 3 to 1 slope at the toe. At one section of the wall we cannot extend our geogrid into the easement. This is located approximately 3.5 feet behind the blocks. Wall height at this section is approximately 15 feet. We can not use any tie backs either. One of the options we are looking at is sheet pile wall with segmental block facing for the above mentioned portion. Does anybody know how to attach sheet piles and segemtnal blocks as facing element? I really appreciate for your help.

Thanks

 

[dirtydude]

I have seen this done with a soldier pile wall. You weld brackets to the face of the wall to hold a pipe spanning between them horizontally. The geogrid then goes from the block to and around the pipe then back to the block.

 

[fargofarmer]

Dirtydude,

Good Idea. Do you know what kind of brackets we need to use?
Do you think it's a good idea to attach segmental blocks to cantilevered sheet pile wall?

Thanks a lot for your qucik response.

 

[RFreund]

Would have suggested the same solution as dirtydude.

The brackets I imagine could be any sort of angle or even a treaded stud that you could attach the steel pipe to.

You do bring up a good point in that there could be a decent amount of deflection at the top of the soldier pile wall but segmental walls are flexible and should be able to handle some deflection.

However I would also add a control joint say 1/4" - 1/2" the entire height of the wall between the normal retaining wall section and the sheet pile wall section. Add some filter fabric behind the units for the full height of the control joint.

EIT

 

[fargofarmer]

RFreund,

I was worrying about deflection earlier. But, you are right that the segmental blocks can take some deflection.
I will consider a control joint between the sheet pile wall portion and normal retaining wall portion.

Thank you.

 

[PEinc]

The majority, if not all, of the deflection should be out of the sheeting before you attach the blocks.

http://www.PeirceEngineering.com

 

[dirtydude]

As mentioned, an angle welded to the sheets and then the pipe welded to the angle should work. You may want to shim the angle out a bit to allow more grid to wrap around the pipe instead of just at the sheet pile bellies.

I agree with PEinc, most of the deflection will be out of the sheeting by the time you complete your excavation and you are placing your bearing pad for the SRW facing.

 

[fargofarmer]

Dear Friends,

I really appreciate for your suggestions and help.

Thanks a lot.

 

[fargofarmer]

What is the minimum factor of safety required for global stability of a segmental block retaining wall? Usually, I consider 1.5 in my analysis.

The wall that I am currently designing will have a wet pond in front of it. Is it reasonable to consider pond with no water (during and/or after construction) as a short term stability condition? what is the minimum factor of safety that I need to get?

thanks

 

[Nuccio]

Here is a detail from Keystone