Double Retaining Wall System

[emilywalters]

thread507-193368

It has been suggested that a temporary sheet pile wall is installed close in front of a permanent mass concrete wall. The sheet pile wall is to be tied back to the mass concrete wall at two locations and the space in between the two then back-filled. I am having difficulty finding any references for the behaviour of the filled soil between the two structures. I saw a similar thread (referenced above) but links to the information are no longer available and I was just wondering if anyone could provide new links to this type of situation.

The mass concrete wall is already designed and I am involved in checking its capability to resist the anchor forces due to installation of the sheet pile wall.

Will the filled soil between the structures behave like a silo? Is it possible that passive resistance to one wall and active pressure on the other wall will occur? Is it over conservative to assume that the pressures cancel out and therefore ignore them when checking the capability of the mass concrete wall to resist the anchor forces? Is this just an impractical system?

http://s12.postimg.org/nyp9rxrv1/Double_Retaining_Wall_Soil_Behaviour.png

 

[BAretired]

I would say there would be active pressure on both walls. You might develop passive pressure against the concrete wall if the gap between the two walls was very large, but pressure would tend to balance if the gap is small.

BA

 

[bridgebuster]

This thread might be useful

http://www.eng-tips.com/viewthread.cfm?qid=280817

 

[Splitrings]

Neither wall can likely rotate sufficiently for active pressures to develope. Its possible the top third of the sheet pile wall may deflect sufficiently to allow active pressures to develope. At the very least these walls should be designed for at rest pressures. If the anchor forces were sufficient and the backfill were saturated(strength reduced sufficiently), a passive failure plane could occur between the walls. Here is a Navy reference that may be of help.

http://www.publications.usace.army.mil/Portals/76/Publications/EngineerManuals/EM_1110-2-2504.pdf

 

[BigH]

If they are that close wouldn't the sheet pile wall be subjected to the "silo" effect? I'd think so . . .