About grain distribution lab
Among the oldest of the soil tests, grain size distribution is widely used in engineering classification. The standard grain-size analysis test determines the percentages of different grain sizes as they are distributed. This is accomplished with the use of sieves. When particles are too fine to be separated using sieves the hydrometer analysis test is completed. The hydrometer method is based on Stokes’ Law, which says that the larger the grain size, the greater its’ settling velocity in a fluid. When a soil sample contains both large and small particles, both test can be performed. This did not prove to be the case for our peat soil.
Conclusions
After performing both the sieve analysis test and the hydrometer analysis test, it was determined the only test that would be useful for this type of soil would be the sieve analysis test. From the sieve analysis test it Cc and Cu were calculated to .6720 and 3.87 respectively. On another note, our hydrometer analysis could not be completed as our specific gravity is not ideal for this test. When looking at table 3, one can see that our specific gravity of .944 is not even listed in the determination of K. Without K, one cannot find the particle diameter or the percent finer which are both needed to complete the hydrometer analysis test. The hydrometer is also used ideally for finer soil samples, which is definitely not the case. Our overall USCS classification is that the sample is Peat and it is based mostly on visual inspection.