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6-Contributor
April 15, 2022
Solved

Need help with geotechnical engineering calculations

  • April 15, 2022
  • 1 reply
  • 2379 views

Hi,

 

This is probably my 2nd week of using mathcad and I've stumbled into a few difficulties.

 

1) Originally, I wanted to try to distinguish between granular and cohesive soils. For Fines content of less than 50%, this should be classified as granular while greater or equal to 50% must be classified as cohesive soils. I wasn't able to do this so I ended up getting the overburden and effective stresses by interpolating the unit weights. Can someone help write a code that can get the final effective stress by distinguishing whether it is granular or cohesive material?

2) In the tab N60 Correction for Overburden Stress, the answers are wrong - I tried this using excel but I don't know why the results from the excel file are not similar to the mathcad file.

 

Hope someone can help!

Best answer by terryhendicott

Hi

Part 2 the errors.

Excel is unitless so handles the empirical formulas as it only has numeric values.

Prime has units so it is necessary un-unit them to get a correct value in the empirical formulas

Capture2.JPG

Cheers

Terry

1 reply

21-Topaz II
April 15, 2022

Hi,

Need to create a table of ones (true) and zeros (false) to represent if soil is granular or cohesive.

Capture.JPG

You can use these masks to calculate the soil values

Capture2.JPG

Cheers

Terry

21-Topaz II
April 15, 2022

Hi

Part 2 the errors.

Excel is unitless so handles the empirical formulas as it only has numeric values.

Prime has units so it is necessary un-unit them to get a correct value in the empirical formulas

Capture2.JPG

Cheers

Terry

6-Contributor
April 16, 2022

Hi Terry! This worked, thanks so much for the help!