4.7
Stewart et al. (2003)
1) Reference
J. P. Stewart, A. H. Liu and Y. Choi, 2003, Amplification factors for Spectral Acceleration in Tectonically active Regions, Bull. Seism. Soc. Am., Vol. 93, No. 1, 332-352.
2) Used
strong motion data
- Area: World wide
- Period: 1940 – 1999 years
- Number of events: 51
- Number of records: 1032
- Magnitude: 4.9 – 7.4
- Epicentral distance: 0 – 118 km
3) Formula
The acceleration response spectrum at base rock was estimated at many sites using empirical formula based on the strong motion records, ground classes and surface shear-wave velocity. The relation between the ground class and the spectral amplification factor, which was derived from the spectrum at surface and base rock, was proposed as follows;
The following classification based on the age + depositional environment / material texture geologic scheme performed.
Following NEHRP classification was adopted as the classification based on the average shear-wave velocity over 30 m from ground surface.
Following classes were used as geotechnical classification.
Table
4.7.1 Coefficients for amplification estimation
|
|
PHA |
|
0.3 sec |
|
1.0 sec |
|
3.0 sec |
||||||||||||
|
Category |
a |
b |
s |
Rej C. |
|
a |
b |
s |
Rej C. |
|
a |
b |
s |
Rej C. |
|
a |
b |
s |
Rej C. |
|
Hlm |
-0.59 |
-0.39 |
0.47 |
100 |
|
-0.39 |
-0.25 |
0.44 |
100 |
|
0.02 |
-0.22 |
0.45 |
100 |
|
0.29 |
-0.19 |
0.48 |
98 |
|
Qa |
-0.15 |
-0.13 |
0.52 |
100 |
|
-0.10 |
-0.11 |
0.51 |
100 |
|
0.20 |
-0.06 |
0.58 |
89 |
|
0.14 |
-0.14 |
0.65 |
99 |
|
Hc |
-0.11 |
-0.10 |
0.52 |
96 |
|
-0.08 |
-0.08 |
0.53 |
90 |
|
0.13 |
-0.06 |
0.57 |
71 |
|
0.00 |
-0.17 |
0.64 |
97 |
|
Hm |
-0.50 |
-0.33 |
0.51 |
100 |
|
-0.33 |
-0.24 |
0.46 |
100 |
|
0.10 |
-0.14 |
0.56 |
98 |
|
0.38 |
-0.09 |
0.55 |
80 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
NEHRP B |
0.09 |
0.05 |
0.48 |
21 |
|
-0.16 |
0.08 |
0.44 |
33 |
|
-0.71 |
-0.13 |
0.78 |
32 |
|
-1.57 |
-0.54 |
0.36 |
99 |
|
NEHRP C |
-0.06 |
-0.05 |
0.55 |
65 |
|
-0.22 |
-0.09 |
0.64 |
89 |
|
0.07 |
-0.03 |
0.74 |
36 |
|
-0.01 |
0.00 |
0.90 |
2 |
|
NEHRP D |
0.08 |
-0.07 |
0.57 |
89 |
|
0.11 |
-0.04 |
0.54 |
68 |
|
0.38 |
-0.02 |
0.48 |
32 |
|
0.44 |
-0.01 |
0.55 |
16 |
|
NEHRP E |
-0.60 |
-0.50 |
0.46 |
100 |
|
-0.49 |
-0.43 |
0.54 |
99 |
|
-0.24 |
-0.46 |
0.48 |
100 |
|
0.47 |
-0.18 |
0.46 |
77 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Geot. B |
0.07 |
0.07 |
0.55 |
51 |
|
-0.02 |
0.15 |
0.66 |
78 |
|
0.24 |
0.25 |
0.73 |
91 |
|
-0.41 |
-0.06 |
0.77 |
27 |
|
Geot. C |
0.11 |
-0.04 |
0.60 |
51 |
|
-0.10 |
-0.12 |
0.62 |
97 |
|
0.04 |
-0.08 |
0.72 |
73 |
|
0.01 |
-0.03 |
0.83 |
28 |
|
Geot. D |
-0.02 |
-0.08 |
0.56 |
94 |
|
0.08 |
-0.04 |
0.51 |
67 |
|
0.41 |
-0.01 |
0.49 |
21 |
|
0.42 |
-0.03 |
0.59 |
45 |
|
Geot. E |
-0.82 |
-0.63 |
0.40 |
100 |
|
-0.89 |
-0.60 |
0.36 |
100 |
|
-0.27 |
-0.49 |
0.45 |
100 |
|
0.54 |
-0.13 |
0.48 |
64 |