Table 3
Spectrum Characteristic Periods (TA, TB )
|
Local Site Class According to Table 12.2 |
TA (s) |
TB (s) |
|
Z1 |
0.10 |
0.30 |
|
Z2 |
0.15 |
0.40 |
|
Z3 |
0.15 |
0.60 |
|
Z4 |
0.20 |
0.90 |
Table 12-1
Soil Groups A-D
|
Soil |
Description |
Standard Penetration |
Density Relative |
Unconf. Strength |
Shear Wave Veloc.(m/s) |
|
(A) |
1.Massive
volcanic rocks, |
>1000 | >1000 | ||
|
2.Very
dense sand and |
>50 |
85-100 | >700 | ||
|
3.Hard clay, silty clay |
>32 |
>400 | >700 | ||
| (B) |
1.Soft volcanic rocks such as tuff and agglomerate, wealthered cemented sedimentary rocks with planes of discontinuity |
500-1000 | 700-1000 | ||
| 2.Dense sand and gravel | 30-50 | 65-85 | 400-700 | ||
| 3.Very stiff clay, silty clay | 16-32 | 200-400 | 300-700 | ||
| (C) |
1.Highly weathrered soft metamorphic rocks and cemented sedimentary rocks with planes of discontinuity |
<500 | 400-700 | ||
|
2.Medium dense sand and grovel |
10-30 | 35-65 | 200-400 | ||
| 3.Stiff clay, silty clay | 8-16 | 100-200 | 200-300 | ||
|
(D) |
1.Soft, deep alluvial layers with high water table |
<200 | |||
| 2.Loose sand | 0-10 | <35 | <200 | ||
|
3.Soft clay, silty clay |
<8 | <100 | <200 |
Table 12-2
Local Site Classes
|
Local Site Class |
Soil Group and Top Layer Thickness |
|
Z1 |
Group (A) soils |
|
Z2 |
Group (B) soils with h1 > 15m |
|
Z3 |
Group (C) soils with 15m < h1 ≤ 50m |
|
Z4 |
Group (C) soils with h1 > 50m |