Soldier pile wall vs MSE wall per day? 1

[alexminr]

I'm working on a design for road widening that will require about 3300 LF of retaining wall, approx 10-25' high. We are evaluating soldier pile vs MSE walls and I need to assess the relative time to construct these walls to factor into the decision.

Option 1 is to furnish soldier piles in drilled shafts with temp. timber laggging and a permanent shotcrete fascia.
Option 2 is to construct an MSE wall with welded wire basket facing.

Any rough estimates of piles per day to compare to square feet or CY of MSE wall per day would be really helpful.

 

[PEinc]

If the wall is a cut-wall, then you may need sheeting just to build the MSE option. This could make the MSE option more expensive than the soldier beam wall. If the wall is a fill wall, then, most likely, the MSE wall will be cheaper. Usually the soldier beam walls and MSE walls are not comparable options.

 

[alexminr]

Our wall is essentially a combination cut/fill wall. It is to widen an existing road out over a very steep slope. The top 5-10' of wall will be essentially fill over the existing shoulder and slope dropping away from the roadway.

But because of the steep slope below the road and the need to provide a horizontal bench below the wall, significant cutting will be required down to a base elevation for an MSE wall. We can open cut into the road to place the geogrid, but to have a wide enough bench to construct the MSE wall requires a taller wall than is required if we place soldier piles and and lagging.

We anticipate the construction cost of the soldier pile option to be greater than MSE, but if it can move faster, the savings on the rest of the project could make it the recommended option.

Any thoughts on relative time to construct for piles and lagging vs MSE? We're assuming the shotcrete facing can be done later and is not on the critical path.

 

[PEinc]

Will you need sheeting to support the road if you build an MSE wall? If so, it may be cheaper to just build a tiedback soldier beam wall.

If you can make a safely sloped open cut to build an MSE wall, it is probably cheaper than a tiedback soldier beam wall. If you need to build temporary sheeting to support the road while you build an MSE wall, then the permanent tiedback soldier beam wall may be cheaper than building a temporary tiedback soldier beam wall and the MSE wall.

 

[MSEMan]

You might want to consider an SMSE wall - shired mechancially stabilized earth wall - FHWA has just published a design manual. THe shoring potion of the wall can be either soil nailing or tie back walls or any shoring system really.

See this link for a good diagram"

http://www.earthteccorp.com/default.asp?contentID=23

 

[alexminr]

Thanks for the new idea. We have actually recommended to the client that we go ahead with soldier pile walls, but this combination option would be good to know about for future projects with similar issues.

 

[PEinc]

The combination wall may not be economical because you are still building 2 individual walls.

 

[JML4TCM]

MSEMan,

Do you have a link or manual number for the FHWA design manual on SMSE wall?

Thanks.

 

[Panars]

Here is the link.

http://www.cflhd.gov/techDevelopment/completed_projects/geotech/smse/