Computer generated Proctor curve 2

[BioBloke]

Hi,
I am currently undertaking remaking the company's workbook for calculating and reporting Nuclear density tests and MDD (Proctor curve) tests. Currently the program does not incorporate the Zero Air Voids chart and the curve is made by plotting the 4 points (Moisture Content & Dry Density) and in excel computer generating a curve on a graph.
I am interested to incorporate the Zero Air Voids line in with the wet side of the proctor curve - is there any way to do this in an excel spreadsheet?

 

[fattdad]

For any given dry density, there is a moisture content that represents complete saturation. This is dependent on the specific gravity of the soil grains. If you have a dry density of 100 pcf and a specific gravity of 2.67, there is 40 percent void space (i.e., 1-(100/(62.4*2.67)). If water were to fill all that void space the weight of that water would be 0.4*62.4 or 25 pounds. That would equate to a moisture content of 25 percent (i.e., the weight of the water divided by the weight of the solids).

Hope this helps.

f-d

¡papá gordo ain’t no madre flaca!

 

[oldestguy]

My "guide book" indicates you can "cut and paste" data from one document to another.

In that case one file would have only the zero air voids curve for your specific gravity, from which you transfer to your production curve file.

Never tried it, but if it works, you would not have to re-invent the zero air voids curve every time.

 

[BigH]

Can you not put a permanent line on your graph portion using drawing - of course, you would need a different graph for each specific gravity (e.g., 2.6, 2.65, 2.7). This would be "permanent" and you wouldn' have to plot it each time.

 

[msucog]

yes can be done similar to that indicated in previous responses. for Proctor curve itself, you will have to play with how to generate a "good" looking curve from the few data points...but it can be done. it works pretty well actually once you get it down.

 

[BioBloke]

i'm posting my excel file for MDD OMC calculating.

i have incorporated the air voids line.

I would like the wet side to mimmick the airvoids line - but don't know how.

I would also like to get the MDD & OMC values to be automatically added to some cells - but do not know if possibe - anyone have any ideas????

Any input into the page would be apprecited.

 

[iandig]

Using excel to plot air void lines is very straight forward, and can be done for any selection of air voids, although in general in UK we tend to only plot the 0%, 5% and 10% air voids.
When I do this, I will set up four colums in excel. the first [A] will be the moisture content, the second will be the 0%, with a header of 0, column C is for 5%, headed 5 and finally column D will be for 10%, and again header 10.
The first row of the spreadsheet contains the particle density, and typically this will be in cell C1.
Therefore the following cells contain the following information.
Cell A1 - worksheet title
Cell C1 - Selected Particle Density
Cell A2 - Title of 'Moisture Content'
Cell B2 - 0 [AS A NUMBER]
CELL C2 - 5
CELL D2 - 10
Cell A3 to An - moisture content in 0.5% incriments, i.e. 0, 0.5, 1.0, 1.5 etc...
Cell B3 to Bn - the following equation "=((1-(B$2/100))/((1/$C$1)+($A3/100)))"
Cell C3 to Cn - the following equation "=((1-(C$2/100))/((1/$C$1)+($A3/100)))"
Cell D3 to Dn - the following equation "=((1-(D$2/100))/((1/$C$1)+($A3/100)))"
Once you have written the first line for cell B3 just copy them down and it will always read the moisture from the left hand column. You only need to type this into the first cell, B3, and copy it to the left, then down for any number of moisture contents.
By setting it up like this, you can play around with different particle densities, air void contents etc... for as many moisture content range you may want. Can even add in the upper and lower MC, plus the interval required and you will only end up plotting the data specific to your sample.
Hope this helps

 

[bb29510]

most people just buy the software that does it for you

 

[msucog]

i'd prefer to build my own spreadsheets for such an application (or most other applications now that i think of it unless i know the source code)

 

[davep043]

I'll admit I'm a relatively older guy at 53, but I read these types of posts and wonder whether its even appropriate to have a computer perform all these functions. Unlike structural engineers, we geotechs work with a material in which every bucketful is at least slightly different from every other bucketful. Even at its most consistent, it is NEVER homogeneous nor isotropic. For us, ta critical part of our performance is experience and judgement in understanding and dealing with the variables in that material. But how many of us ever question the result that a computer program spits out? And if we never question them, how much of that experience and judgement are we reauly using?