Introduction
The purpose of this lab was to determine the particle size distribution of a particular soil sample by carrying out sieve analysis and hydrometer analysis tests. For the sieve analysis test, a graph for percent finer versus the grain size was plotted from the data collected. The graph was used to determine whether the soil sample was fine-grained or course-grained. Calculations for uniformity and gradation were then done to determine whether the soil was well graded, poorly graded or gap graded.
For the hydrometer analysis test, the soil sample was dispersed in water so that the particles settled at different velocities with time. The percentage of soil suspended at specific time intervals were measured …show more content…
Also it prevents pavement failures in roads. Through grain size analysis Engineers are able to know the major clay type in a particular soil sample. Calculate D10, D30, and D60.
D60=0.32mm
D10=0.016mm
D30=0.12mm
To determine the mean grain size (D50)
The mean grain size, D50 is 0.25mm
To determine the uniformity Coefficient (Cu) and the Coefficient of Gradation (Cc). What do these two coefficients tell you about the soil?
Cu=D60/D10=0.32/0.016=20
Cc=D230/(D60*D10) =0.122/ (0.32*0.016) =2.8125
The soil is well graded since its Cu is 20 hence greater than 6 and the Cc is 2.81 hence between 1 and 3. Classification of the soil according to USCS.
Cu is greater or equal to 4 and Cc is between 1 and 3. The group name of is well graded soil and the group symbol is GW. Classify according to AASHTO.
More than 35% of the granular materials pass through the 0.075mm sieve hence it is classified as A-1
The soil grading