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Section 5
5-307
Soil Type parameter is used to define the subsoil conditions
based on which the response spectra will be generated. Based on
the subsoil conditions the soil types may be of three kinds
Type A : for Rock or stiff deposits of sand
Type B :- for deep deposits of medium dense sand,gravel or
medium stiff clays.
Type C:- Loose cohesionless soil deposits or deposits with soft to
medium stiff cohesive soil.
Please refer section 3.2 of Eurocode 8 for detailed guidelines
regarding the choice of soil type.
ALPHA f7 :- Alpha is defined to be design ground acceleration
expressed in terms of acceleration due to gravity(g).For most of
the application of Eurocode 8 the hazard is described in terms of a
single parameter, i.e., the value of effective peak ground
acceleration in rock or firm soil ; this acceleration is termed as the
design ground acceleration.
Q f8 :- Q is the behavior factor used to reduce the elastic response
spectra to the design response spectra. The behavior factor is an
approximation of the ratio of the seismic forces, that the structure
would experience, if its response was completely elastic with 5%
viscous damping, to the minimum seismic forces that may be used
in design- with a conventional linear model still ensuring a
satisfactory response of the structure.
Modal Combination Description
based on which the response spectra will be generated. Based on
the subsoil conditions the soil types may be of three kinds
Type A : for Rock or stiff deposits of sand
Type B :- for deep deposits of medium dense sand,gravel or
medium stiff clays.
Type C:- Loose cohesionless soil deposits or deposits with soft to
medium stiff cohesive soil.
Please refer section 3.2 of Eurocode 8 for detailed guidelines
regarding the choice of soil type.
ALPHA f7 :- Alpha is defined to be design ground acceleration
expressed in terms of acceleration due to gravity(g).For most of
the application of Eurocode 8 the hazard is described in terms of a
single parameter, i.e., the value of effective peak ground
acceleration in rock or firm soil ; this acceleration is termed as the
design ground acceleration.
Q f8 :- Q is the behavior factor used to reduce the elastic response
spectra to the design response spectra. The behavior factor is an
approximation of the ratio of the seismic forces, that the structure
would experience, if its response was completely elastic with 5%
viscous damping, to the minimum seismic forces that may be used
in design- with a conventional linear model still ensuring a
satisfactory response of the structure.
Modal Combination Description
SRSS Square Root of Summation of Squares method.
CQC
CQC
Complete Quadratic Combination method. Default.
ASCE ASCE4-98 method.
ABS
ABS
Absolute sum. (Very conservative worst case)
TEN
Ten Percent Method of combining closely spaced modes.
NRC Reg. Guide 1.92 (1976).