Review of a Consolidation Test Report 1

[learning2geotech]

When reviewing a consolidation test report, what do you guys look for?

How do you tell if the sample was heavily disturbed?

Have you ever disregarded a consolidated test because it didn't make sense? What didn't make sense?

 

[oldestguy]

This question:
How do you tell if the sample was heavily disturbed?

If there is significantly rounding of the curve (two sections joining) as it hits the sloping section, I blame that on disturbance.

 

[EireChch]

Many geotech discuss the issue of sample disturbance. There are menthods to even assess the amount of sample disturbance.

You should read the literature, give you own thoughts and then wait for responses.

The best way to get a response is to say something that is incorrect!

 

[fattdad]

I look to see to what extent they have proper index properties.
I look to see if the weight-volume relations make sense - also whether they back calculated Gs from an S=100 assumption.
I look to see whether the time readings were extended long enough to capture C-sub-alpha.
I look to see if they used the Cassagrande construction of Pp, as my program requires it and it's an element of the ASTM Standard.
I look to see if the computer made the plot using straight lines between the data points. My program doesn't allow it as you can't ascertain the point of maximum curvature from straight lines.
I also look at the boring logs to see if the undisturbed sample came from the meaningful stratum and from the interval most likely to be compressible. Water contents can help with that!
I look at the load interval Cv values to see which value means something to me.

Not sure your end game.

f-d

ípapß gordo ainÆt no madre flaca!

 

[geotechguy1]

Considering the volume of the sample tested in a consolidation test vs the size of the soil that will be loaded in the field, and the amount of lateral and vertical variation in material properties, and the inability of a consolidation test to properly assess the bulk effects / performance of a soil deposit...I wouldn't worry to much about it as long as the test was performed according to the ASTM standard and they didn't toss the shelby tube off a building after sampling. As for disregarding them, I always take them with a grain of salt the size of a small city

 

[Okiryu]

See attached for checking the effect of sample disturbance in the e-log p curve. I would also check typical values for Cc and Cr from the literature and the preconsolidation pressure based on your site geology.

 

[GeoEnvGuy]

I look at the slope of the compression curve then the recompression curve.