Recent content by AussieGeoEng

By rebound, I am assuming you are referring to unloading? For a saturated soil this is analogous to consolidation, however mv will be different and affect the calculated cv.

I find it strange that the onus is on the tester to prevent the sample from cracking. You should be able to complete this test in a standard triaxial (noting a confining pressure of 100 kPa). Just check the capacity of the load cell. A 5kN load cell is good for up to 2500kPa axial stress.

I assumed you figured this out - but it sounds like you have a leak.

Check out the paper below, where a method is proposed for determining wP based on the fall cone. Feng, T. W. (2000). Fall-cone penetration and water content relationship of clays. Geotechnique, 50, 181-187. I don't think this has really been picked up in practice, but in a discussion by Prof...

I disagree with dBasement... if the soil swells or shrinks then your dry density will change. For example, if you have an expansive clay and it was placed dry of optimum and there was a wet period, then chances are that you dry density will have reduced (swelling), on the other hand if you have...

If you are changing the relative humidity of the pore space, then using Kelvin's law (see Fredlund & Rahardjo,1993) you are altering the suction. So if the relative humidity is decreasing, then suction is increasing resulting in the compression you are observing.

You can calculate it from the phase relationship w(Gs)=e(Sr)... If you know density/void ratio (e) and specific gravity (Gs), adopt Sr=1.0 and calculate w.

You first need to check that the failure envelope will extend into the clay. Bowles (1995) has some guidance on this. Bearing capacity is sum of the bearing capacity of the clay plus a contribution due to shearing of the sand - roughly worked out based on the perimeter of the foundation...

When referring to a passive wedge it is typically the wedge of soil in front of a retaining wall.

f-d & BigH, Thanks for the last two posts. f-d do you have any references to the work you talked about? I will have some more reading to do.

f-d, I realise that the optimum varies for each compaction level. I like to think of the SP OMC as a good reference. I have heard of other moistures - even machine optimum. Which would be the optimum moisture for achieving compaction with a certain type of machine and compaction procedure...

If they don't provide money for testing you may as well pluck numbers from thin air. Give them plenty of scatter so no one can make sense of them. :-)

I would tend to disagree - moisture content is important. If the test was completed on different samples, then that is another story. A relative compaction of 99% can be achieved dry of optimum - it would however require significantly more effort. I.e similar to the shift in the compaction...

Is the compaction static or dynamic (e.g. Proctor)? If it is static then you can measure the load. With dynamic it depends on the amount of energy exerted - I would usually esitmate around 200kPa. Therefore no, I would not call the sample dynamically compacted NC. With the oedometer you can...

There are two procedures to produce specimens in the laboratory. Compaction or reconstition. You mention both so a little confusing? Reconstitution is preparing a sample at a moisture (well) content inexcess of the liquid limit. Then consolidating (note the difference between compaction -...