OTHER GEOTECHNICAL EARTHQUAKE ENGINEERING ANALYSES - Geotechnical Earthquake Engineering - page 365

TABLE 11.4 Seismic Source Type

Seismic source definition

Seismic source Seismic source Maximum moment

type description magnitude M w Slip rate, mm/yr

A Faults that are capable of producing M w 7 SR 5

large-magnitude events and that

have a high rate of seismic activity

B All faults other than types A and C M w 7 SR 5

M w 7 SR 2

M w 6.5 SR 2

C Faults that are not capable of M w 6.5 SR 2

producing large-magnitude

earthquakes and that have

a relatively low rate of seismic

activity

Notes: Data obtained from the Uniform Building Code (1997). Seismic source type is only needed if the seis-
mic zone 4 (see Table 11.2). Subduction sources shall be evaluated on a site-specific basis. For the seismic source
definition, both the maximum moment magnitude M w and slip rate (SR) conditions must be satisfied concurrently
when determining the seismic source type.

TABLE 11.5 Seismic Coefficient C v

Seismic zone (see Fig. 5.17)

Soil profile type Zone 1 Zone 2A Zone 2B Zone 3 Zone 4

A 0.06 0.12 0.16 0.24 0.32 N v

B 0.08 0.15 0.20 0.30 0.40 N v

C 0.13 0.25 0.32 0.45 0.56 N v

D 0.18 0.32 0.40 0.54 0.64 N v

E 0.26 0.50 0.64 0.84 0.96 N v

F Soil requiring a site-specific evaluation (see Sec. 11.5.2)

Data obtained from the Uniform Building Code (1997). Obtain N v from Table 11.6.

surface projection of the fault plane). If there are several sources of seismic activity, then
the closest one to the site should be considered to be the governing case.
b. Seismic source type: The data in Table 11.4 can be used to determine the seismic
source type (A, B, or C).
c. Near-source factor N a : Given the seismic source type and the closest distance to a
known seismic source, the near-source factor N a can be determined from Table 11.3.
4. Seismic coefficient C v : Given the seismic zone and the soil profile type, the seismic
coefficient C v can be obtained from Table 11.5. If the seismic zone is equal to 4, then the
near-source factor N v must be known. To calculate the near-source factor N v , the following
steps are performed:
a. Closest distance to known seismic source: As outlined in step 3 a, the closest distance
to the known seismic source must be determined.