The number of blows observed in an SPT for different penetration depths is given in the table below.
| Penetration sampler (mm) | Number of blows |
|---|---|
| 0 - 150 | 7 |
| 150 - 300 | 18 |
| 300 - 450 | 21 |
The observed N value is
1
39
2
7
3
46
4
25
The number of blows observed in an SPT for different penetration depths is given in the table below.
| Penetration sampler (mm) | Number of blows |
|---|---|
| 0 - 150 | 7 |
| 150 - 300 | 18 |
| 300 - 450 | 21 |
The observed N value is