Site Soil Characteristics

Coefficient,
S

Type

Description

S₁




S₂


S₃


S₄

A soil profile with either :
a)  A rock-like material characterized by a shear-wave velocity greater than
     762 m/s or by other suitable means of classification, or
b)  Stiff or dense soil condition where the soil depth is less than 61 metres

A soil profile with dense or stiff soil conditions, where the soil depth exceeds
61 metres

A soil profile 21 metres or more in depth and containing more than 6 metres of
soft to medium stiff clay but not more than 12 metres of soft clay

A soil profile containing more than 12 metres of soft clay characterized by a
shear wave velocity less than 152 m/s

1.0



1.2


1.5


2.0

Note : (1)     The site coefficient shall be established from properly substantiated geotechnical data. In locations
                    where the soil properties are not known in sufficient detail to determine the soil profile type, soil
                    profile S₃ shall be used. Soil profile S₄ need not be assumed unless the building official determines
                    that soil profile S₄ may be present at the site, or in the event that soil profile S₄ is established by
                    geotechnical data.