Micropiling of I-Section Piles - Too many refusals

[Simon_No_Idea]

Hello all,

We're having no luck ramming our ca. 150mm I-section piles into the ground.

As per the Geotech, the ground is very hard with lots of rocks of up to dia. 300mm.

What to do? We've tried pre-drilling with an auger but it seems this method won't achieve the desired results.

What else can we try?

Thanks in advance.

Regards,
Simon

 

[oldestguy]

Please say more about the job and loads to be carried and then maybe some help from here. Without anymore info I'd say look at conventional footing foundations.

 

[dik]

OG... with hard ground... seems like spread or strip footings...

Dik

 

[WARose]

I'm confused: you mention micropiles in the intro......but in your main post you talk of "ramming" I-sections into the ground?

Micropiles are made to go into bedrock. You drill right into it and bond to the sides. I've gone into very dense rock with them before and gotten hundreds of tons of capacity. No need to ram/drive anything.

You may want to contact a micropile contractor for a solution. Hayward Baker is a good one to talk to.

 

[BigHarvey]

You cannot drive 150 I beams in blocks 300mm diameter (you won't find that in a textbook, it's just common sense !). Your only option is to drill with an overburden (OD)technique like ODEX or Symmetrix, remove the DTH hammer drill string, drop you I beam Inside the casing (don't forget to use spacers) grout and then remove the casing.