How to intrepretate the penetrograph of soil penetration resistance
How to intrepretate the penetrograph of soil penetration resistance
(OP)
In our project we are adopting penetration resistance using base surface cone for measuring in situ compaction of soil. During the test instrument records the resistance of soil in a graph. Can any one help me about how to intrepretate the results of penetrograph to arrive the in situ compaction of the soil.





RE: How to intrepretate the penetrograph of soil penetration resistance
I am not sure I have ever heard of a penetrograph. Is it like a Dynamic Cone Penetrometer (DCP) or a McIntosh Probe?
In Perth, Western Australia, compaction testing for large sand fill projects is usually done with a DCP. Reference penetration values are usually established with nuclear densometer and compaction testing at the start of the job. The correlations are usually very reasonable.
In my experience DCP testing in clays is usually too variable to be of use.
Hope this helps.
KV
RE: How to intrepretate the penetrograph of soil penetration resistance
Why not a nuke gauge or a sand cone? They are much more direct indications of density, and are easy to interpret. I don't like to use test methods that I don't understand.
RE: How to intrepretate the penetrograph of soil penetration resistance
AS (Australian Standard) 3798 - Guidelines on Earthworks for Commercial and Residential Developments - Section 7.2, allows for indirect in situ testing methods to assess in place dry density.
In direct methods include penetrometer testing as specified in AS 1289.6.3.2 and require some calibration with a direct in situ testing method (sand replacement, nuke testing, etc..)
In general practice the penetrometer testing is performed in association with moisture content testing to infer a in place field density in sand soils.
Aside from dry collapse issues, sand is a much more forgiving material than clay and silts and penetrometer testing is usually considered acceptable by design engineers for residential and light commercial sand fill projects in Perth.
And it's not a surprise its not common practice in the US. You guys are usually behind ;P.
KV
RE: How to intrepretate the penetrograph of soil penetration resistance
Are you working the night shift in Oz
RE: How to intrepretate the penetrograph of soil penetration resistance
The fill is usually placed in accordance with a method specification which is determined at the start of the job by trial runs and nuke testing. The DCP is used for production quality control during the filling works.
These projects are relatively large and usually involve several metres of fill. The sand materials in the Perth region of Western Australia are typically fairly clean.
For clays and other materials nuke testing is usually the method of choice for assessing field densities.
gadderrao, I hope this helps. There is precendent for using penetrometer testing for compaction control, but I would only recommend it for fairly clean and uniform sand fills. Anything else stick to densometers.
Dgillette, born and raised in Oz now I live and work in Canada. Just like home only wetter, colder and completely different.
RE: How to intrepretate the penetrograph of soil penetration resistance
RE: How to intrepretate the penetrograph of soil penetration resistance