SPT Test using a cone tip?

[jjesik]

Has anyone used this before? Is there an ASTM standard? What is the test called.

We used it at a site in South America. The same hammer, count the blows to penetrate the ground 15cm like the SPT but there was a solid cone at the tip instead of a SPT barrel.

 

[BigH]

I don't think this is an ASTM Standard - but it was pretty "standard" when I worked in Canada - called the 'pentest' - the cone was 51mm 60 apex angle. We usually counted the blows at 300mm not 15mm. It was well described in the first Canadian Geotechnical Engineering Manual.

 

[moe333]

There were some good side by side studies done between the pentest and SPT showing a pretty good correlation depending on material type. But I can't recall the name of the author/papers. The studies did show that at depth (maybe greater than 40 feet?) rod friction in the pentest became a big factor and the correlation diverged.

 

[Ron]

The dynamic cone penetrometer has been used for many years to characterize near surface soils. For downhole testing, the static cone penetrometer is usually used.

The DCP that I have used and has been used my many departments of transportation in the US, is a manual device using a 15 lb hammer instead of the 140 lb SPT hammer.

 

[moe333]

The one I used was in Canada and similar to that described by BigH; mounted on a track drill rig with 140 lb hammer and 30" drop, same as SPT. The advantage was continuous data and quick.