Refer to Problem 3.5. Using Eq. (3.28), determine the average relative density of the sand. Assume it is a fine sand. Use Eq. (3.13) to obtain (N₁)₆₀.

Problem 3.5

Following is the variation of the field standard penetration number (N₆₀) in a sand deposit:

Depth (m) .............. N₆₀
1.5 ............................. 6
3 ................................ 8
4.5 ............................. 9
6 ................................ 8
7.9 ........................... 13
9 .............................. 14

The groundwater table is located at a depth of 6 m. Given: the dry unit weight of sand from 0 to a depth of 6 m is 18 kN/m³, and the saturated unit weight of sand for depth 6 to 12 m is 20.2 kN/m³. Use the relationship given in Eq. (3.13) to calculate the corrected penetration numbers.

Eq. (3.13)

Eq. (3.28)

1 0.5 CN Pa ||