Section 5
5-153
5.27.3 Automatic Spring Support Generator for
Foundations
STAAD has a facility for automatic generation of spring supports
to model footings and foundation mats. This command is specified
under the SUPPORT command.
General Format:
SUP
PORT
⎧X ⎫
⎧joint-list ELASTIC FOOting f1 (f2) ⎫ ⎪XOnly ⎪
⎨joint-list ELASTIC MAT ⎬ DIR ⎨Y ⎬ SUBgrade f
3
⎩plate-list PLATE MAT ⎭ ⎪YOnly ⎪
⎪Z ⎪
⎩ZOnly ⎭
⎧ ⎫
(PRI
NT) ( ⎨ COMP ⎬ )
⎩ MULTI ⎭
plate-list PLATE
MAT DIR ALL SUBgrade f3 (f4 f5)
⎧
⎫
(PRI
NT) ( ⎨ COMP ⎬ )
⎩ MULTI ⎭
where
f1, f2 = Length and width of the footing. If f2 is not given, the
footing is assumed to be a square with sides f1
X,Y,Z = Global direction in which soil springs are to be
generated
f
3
= Soil sub-grade modulus in force/area/length units.
ALL option
f3, f4, f5 = Soil sub-grade modulus in force/area/length units in Y,
X, Z directions respectively. f4, f5 default to f3 if
omitted.
