Page 144 - Pressure Vessel Design Manual

Design of Vessel Supports 123

Table 3-9a Table 3-9b
Seismic Coefficient Ca* Seismic Coefficient Cv*
Soil Profile I Seismic Zone Factor, Z Soil Profile Seismic Zone Factor, 2

Type Z=0.075 Z=0.15 Z=0.2 Z=0.3 Z=Q.4 Type 2=0.075 Z=0.15 Z=0.2 Z=0.3 Z=0.4
0.06 0.12 0.16 0.24 0.32Na
0.08 0.15 0.20 0.30 0.40Na
0.09 0.18 0.24 0.33 0.40Na 0.25 0.32 0.45 0.56Nv
0.12 0.22 0.28 0.36 0.44Na 0.18 0.32 0.40 0.54 0.64Nv
0.19 0.30 0.34 0.36 0.36Na S€ 0.26 0.50 0.64 0.84 0.96Nv
See Footnote 1 SF See Footnote 1
’Sitespecific geotechnical investigation and dynamic site response analysis shall ’Sitespecific geotechnical investigation and dynamic site response analysis shall
be performed to determine seismic coefficients for Soil Profile Type SF. be performed to determine seismic coefficients for Soil Profile Type SF.

Table 3-9c
Soil Profile Types‘
~
Average Soil Properties for Top 100 Feet (30,480 mm) of Soil Profile I
TvDe I Description feeusecond (ds) cohesionless soil layers] (blowdfoot) Strength, so psf (kPa)
Soil Profile Soil Proflle Name/Generic Shear Wave Velocity, V, Standard Penetration Test, N [or NcH for Undrained Shear

>5,000 (1,500)
- -
2,500 to 5,000
(760 to 1,500)
Very Dense Soil and Soft 1,200 to 2,500 5 50 > 2,000
Rock (360 to 760) (100)
Stiff Soil Profile 600 to 1,200 15 to 50 1,000 to 2,000
(1 80 to 360) (50 to 100)
I (50)
Soft Soil Profile c600 (1 80) ~ 15 I < 1,000 I

I
Soil Requiring Site-specific Evaluation. See Section 1629.3.1.
I

Table 3-9e
Table 3-9d Seismic Source Type’’
Near-Source Factor NP, N,
Seismic Source Deflnitlon2
Closest Distance to Maximum
Known Seismic Sourcezg3 Seismic Seismic Source Moment Sllp Rate,
Source
TY Pe Description Magnitude, M SR (mmlyear)
Seismic Source Type 52 km 5 km 10 km 215 km
A Faults that are capable of M ? 7.0 SRz5
Nv Na Nv Na Nv Na Nv Na producing large
magnitude events and that
A 2.0 1.5 1.6 1.2 1.2 1.0 1.0 1.0 have a high
6 1.6 1.3 1.2 1.0 1.0 1.0 1.0 1.0 rate of seismic activity
C 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0 All faults other than M ? 7.0 SR<5
Types A and C M < 7.0 SR>2
‘The Near-Source Factor may be based on the linear interpolation of values for M 26.5 SR<2
distances other than those shown in the table.
’The location and type of seismic sources to be used for design shall be estab- C Faults that are not capable of M < 6.5 SRs2
lished based on approved geotechnical data (e.g., most recent mapping of active producing large
faults by the United States Geological Survey or the California Division of Mines magnitude earthquakes and
and Geology. that have a relatively low rate
?he closest distance to seismic source shall be taken as the minimum distance of seismic activity
between the site and the area described by the vertical projection of the source on
the surface (i.e,, surface projection of fault plane). The surface projection need not Subduction sources shall be evaluated on a site-specific basis.
include portions of the source at depths of 10 krn or greater. The largest value of ’Both maximum moment magnitude and slip rate conditions must be satisfied
the Near-Source Factor considering all sources shall be used for design. concurrently when determining the seismic source type.
‘Reproduced from the 1997 edition of the “Uniform Building Code,” copyright 1997, with permission from publisher, the International Conference of Building Officials.