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Code Name National Building Code of Canada
Issued by Associate Committee of the National Building Code, National Research Council of Canada
Revision No change from the 1996 version
Horizontal Base Shear

Ve: Equivalent lateral force at the base of the structure  representing elastic response

R: Force modification factor that reflects the capacity of a structure to dissipate energy through inelastic behavior
(See Table 1)

U: Factor representing level of protection based on experience (0.6)

v: Zonal velocity ratio = the specified zonal horizontal ground velocity expressed as a ratio to 1 m/s

S: Seismic response factor, for unit value of zonal velocity ratio (See Table 2, Fig. 1)

I: Seismic importance factor of the structure

Seismic importance factor:
 The seismic importance factor I shall equal 1.5 for post-disaster buildings, 1.3 for schools and 1.0 for all other buildings.

F: Foundation factor (See Table 3)

W: Dead load plus 25% of the design snow load plus 60% of the storage load and the full contents of any tanks