How to perform in laboratory static compaction same as proctor compaction(dynamic compaction)?

[bobjam]

Hi to All

I want to perform static compaction on remolded soil samples and compare the subsequent results( optimum moisture and dry density) with proctor compaction resaults using an unconfined compression test apparatus , My question is how to unify corresponding loads  applied on each samples from static compaction to proctor falling hammer loads to achieve somehow same loading

I mean if the energy from proctor test for example on upper surface area of the soil is 50000 lb.ft/ft3, How much force  I should put on the sample in unconfined compression test? ( probably a constant rate)

I would be grateful if you could introduce me to some of works  related to my question

 

[oldestguy]

Why? It's not ASTM and may result in legal problems.

 

[bobjam]

As you may know , in fieldو compaction normally is done by static rollers , and studies show There are numerous inconsistency between proctor results and reality , therefore an inventive approach which by the way is already under investigation by researchers would be an interesting idea.

 

[Ron]

bobjam....your quest is the holy grail of compaction. You're not the first to pursue this concept and won't be the last.

When properly done in the lab and properly used in the field, a Proctor is a valuable tool and works quite well. It's not perfect; however, it can be done with relatively inexpensive equipment and results are repeatable.

Many have chased the relative density route as being better. Major problems....expensive equipment, finicky test, labs won't invest in the equipment for the level of work it develops.

 

[bobjam]

Thanks man, You are right, Unfortunately labs don't support the idea, to be honest the real deal for me is that I want to do direct shear test on soil samples and to do so I am preparing my samples with optimum moisture driven by Proctor standard test ,and I apply for example 30kpa load on shear box to overconsolidate my samples before curing them for a certain period of time
Put that aside, at the same time I want to prepare samples for Unconfined Compression test and If I add optimum moisture to the mixture , a question arises for me as to whether or not I compact them( it probably is required because my soil is clayey sand) and if so how in this case I could compact soil samples to reach same density as or maybe a little less than proctor, and how I could measure relative density
Do you or The Oldestguy happen to know about that?
Again Thanks a lot to you and The Oldestguy

 

[fattdad]

the answer is not clear. . .

There is a line of optimums for the Standard Proctor, the Modified Proctor, the sheepsfoot compactor, the vibratory compactor, the static compactor, the rubber tire, etc. In the lab, we find an optimum water content to attain 100 percent of the maximum dry density. Tradition claims that this is the optimum water content for 95 percent compaction also - it's not!

All we can do is our best and inform our approach using known conventions. You compact dry of, "Optimum" and you'll get better strength. Compact wet of, "Optimum" and you'll get lower permeability.

Crazy study of engineering we are into, eh?

f-d

ípapß gordo ainÆt no madre flaca!

 

[oldestguy]

Again why? Explain the job and why the current way won't work or other reason. If the client agrees to some experimenting, maybe, but other factors down the road may comer up to bite you. Why is shear strength needed? Many times it is compression or settlement that needs improvement and soil rupture is not a factor..

 

[bobjam]

The last line was awesome, pretty crazy
in the above mentioned post I asked a question about Unconfined Compression and direct shear test could you suggest me some solutions or maybe a paper regarding that.

 

[oldestguy]

For compression, the test would be run in a consolidometer, even if it is a sandy sample. If you can find papers by B.K.Hough, such as his "Compressibility as the basis for soil bearing value" #2135 in SM Journal of ASCE August 1959. He developed a method that has shown to be fairly accurate. His second edition of his text "Basic Soils Engineering" Ronald Press has info on it also.

Also he ties in N value from the SPT data of borings.

 

[aeoliantexan]

I may be misunderstanding your question, but I remember when I was in college (many years ago) clay samples were compacted for triaxial tests by placing a measured amount of soil in a steel cylinder, inserting a steel piston just a little smaller, and pushing the piston down with a universal testing machine to a mark on the piston that would produce a known volume. I always wondered how uniform the density was within the sample, but the practice seemed to be common, and I assumed there was a standard for it.