In order to determine the group name, we refer to Figure 5.4.
So, the group name is poorly graded sand with clay.
Soil B
The grain-size distribution curve in Figure 5.7 shows that percent passing No. 200 sieve
is 61 (50%); hence, it is a fine-grained soil. Given: LL 26 and PI 26 20 6.
In Figure 5.3, the PI plots in the hatched area. So, from Table 5.2, the group symbol is
CL-ML.
For group name (assuming that the soil is inorganic), we go to Figure 5.5 and
obtain Plus No. 200 sieve 100 61 39 (which is greater than 30).
Percentage of gravel 0; percentage of sand 100 61 39
Thus, because the percentage of sand is greater than the percentage of gravel, the soil
is sandy silty clay. ■
P