Geogrid as structural tieback for bulkhead

I am looking at designing a short marine bulkhead (approx. 10' exposed height, and 10' embedment) and want to use an anchored prestress sheet pile, but instead of a traditional steel rod & deadman/anchor pile, was looking at using a layer of high strength geogrid at the top of wall in its place. There will be a good amount of fill above wall to engage the geogrid.

I was wondering if anyone has heard of or used geogrid in this type of application, or could point out any design/construction concerns I should look into.

Thanks so much.

 

[layfieldman]

I've never heard of this application but the FHWA has a great manual on mechanically stabilized earth design.

A little more information would be necessary before any informed comment could be made though. My one uninformed comment on this without any further information would be how you plan on connecting the geogrid to the wall.

 

[VEGEO]

I imagine that what you are trying to do is to minimise the risk of corrosion inherent in the traditional anchor system.

Geogrid is unlikely to provide the amount of resistance that you need to provide an effective prop in the top third of the sheet pile wall. Additionally you'll have a hell of a time coming up with a suitable connection detail (not to mention the problem of post tensioning it.)

I might look at precast concrete anchor elements connected to the sheet piles with polyester strap soil reinforcement and GFRP dowels.

 

[bplech]

You may find help by researching the manufactures recommended procedures of Segmental Retaining Walls. In addition, there are many manufactures of the geogrid fabric that provide support for different applications. The idea that you present is possibly new to them but they may provide some of their own input that may help.

 

[BigH]

If you use geogrid - you will need to look at the creep aspect as well - ensure you don't get much. In India, I understand that some MSE walls didn't behave that well with geogrids - but that could be an Indian characteristic!