Driven vs Grouted Soil Nails

[Obregon]

Good morning all. Does anybody have knowledge/experience on the construction of driven soil nailing walls as opossed to dirlled & grouted nails for temporary works? Savings, reliability? Thank you.

 

[PEinc]

A drive nail should have a much lower capacity per unit of length.
Driven nails may not be possible in difficult ground conditions (rock, cobbles, boulders, very dense soil)'
Very small diameter means very little area to bond or adhere to the ground surface.
Some company is promoting a soil nail launcher that shoots the nail into the ground'
None of my many clients uses driven or shot soil nails.

http://www.PeirceEngineering.com

 

[Kevin9679]

Possible savings, but rarely especially in America because there's so much more competition for drilled. Supposedly driven nails will have a stronger bond per surface area, but it's a moot point when grouted bars have 4-8x the surface area. Corrosion may also be an issue.

 

[Okiryu]

My understanding is that in the US, driven nails are allowed for temporary applications only. I am located in Japan and savings are significant in my experience. Sometimes we have installed them for permanent conditions to reinforce slopes because the SOW instructed us to do that. I would say that 95% of the cases when we used driven nails to permanently reinforce slopes, they worked out fine (we have not heard of further failures).