March 3, 2011
|
Seismic,
RISA-3D,
Loads,
New
RISA-3D
now
has
the
ability
to
define
the
seismic
parameters
Rho,
Omega
and
SDS
directly
into
load
combinations.
If
you
open
the
Basic
Load
Cases
spreadsheet
and
click
into
the
BLC
column,
the
dialog
offers
the
ability
to
add
these
values
in
to
factor
the
load.
Here
we
will
see
that
Rho
and
Omega
can
only
be
used
if
the
Load
Category
Code
is
set
to
a
seismic
option.
Sds
can
only
be
used
if
Dead
Load
is
selected.
Once
you
apply
this
factor
it
is
automatically
taken
into
account
without
the
use
of
the
Factor
column
in
the
Load
Combinations
spreadsheet.
The
actual
values
for
these
factors
are
defined
in
the
Seismic
tab
of
Global
Parameters.
Rho
is
specified
in
section
12.3.4
of
the
ASCE
7-16.
Omega
is
specified
in
Table
12.2-1.
SDS
is
used
for
the
vertical
portion
of
seismic
load
and
is
typically
multiplied
by
0.2*DL
in
Section
12.4
combinations…
