Reference Load in STAAD Pro

(1) I define reference load in reference load definition like

LOAD R1 LOADTYPE Dead  TITLE R1 DL

SELFWEIGHT Y -1
MEMBER LOAD
145 146 149 153 156 158 TO 161 163 TO 165 169 TO 171 173 174 179 183 TO 185 -
204 205 208 212 215 217 TO 220 222 TO 224 228 TO 230 232 233 238 242 TO 243 -
244 UNI GY -15
147 148 152 166 167 172 175 TO 177 180 TO 182 186 206 207 211 225 226 231 -
234 TO 236 239 TO 241 245 UNI GY -7.5
263 264 267 TO 269 271 TO 278 280 TO 283 287 TO 289 291 296 301 303 UNI GY -5
279 292 297 298 302 UNI GY -11
150 154 155 157 162 178 209 213 214 216 221 237 UNI GY -2
ONEWAY LOAD
_ONEWAY ONE -3.175 GY
_ONEWAY ONE -1.8 GY
_STAIR ONE -4.5 GY TOWARDS 220
_STAIR ONE -2 GY TOWARDS 220
FLOOR LOAD
_TWOWAYROOF FLOAD -3.175 GY
_TWOWAYROOF FLOAD -1.8 GY
ONEWAY LOAD
_ONEWAYROOF ONE -3.175 GY
_ONEWAYROOF ONE -1.8 GY
_STAIRROOF ONE -3 GY TOWARDS 279
_STAIRROOF ONE -1.5 GY TOWARDS 279
_HEADROOM ONE -3.175 GY
_HEADROOM ONE -1.8 GY
MEMBER LOAD
73 TO 77 79 TO 81 84 86 TO 89 91 TO 95 97 TO 105 107 TO 114 UNI GY -3
FLOOR LOAD
_TWOWAY FLOAD -3.175 GY
_TWOWAY FLOAD -1.8 GY


LOAD R2 LOADTYPE Live TITLE R2 LL


ONEWAY LOAD
_ONEWAY ONE -2 GY
_STAIR ONE -3 GY TOWARDS 220
FLOOR LOAD
_TWOWAYROOF FLOAD -1.5 GY
ONEWAY LOAD
_ONEWAYROOF ONE -1.5 GY
_STAIRROOF ONE -2 GY TOWARDS 279
_HEADROOM ONE -1 GY
FLOOR LOAD
_TWOWAY FLOAD -2 GY

Now I want to add seismic weight in seismic definition using above reference loads R1 and R2

DEFINE 1893 LOAD
ZONE 0.1 RF 5 I 1 SS 2 ST 1 DM 0.05 GL 0.9
REFERENCE LOAD Y
R1 1.0 R2 0.25

Here I should provide R1 1.0 R2 0.25 (+ve sign) or Should Provide R1 -1.0 R2 -0.25 (-ve sign)? Because we provide reference load with -Y direction and in seismic weight we use +ve sign.

(2) When we define reference load LOADTYPE Live  what will be the effect when I select REDUCIBLE PER UBC/IBC or deselect it? If I select it then I have not to provide reduced factor with live load in seismic definition?

Parents
  • You need to provide R1 1.0 R2 0.25 when defining the seismic weight.

    The reducible option results in reduction in the applied live load under certain conditions as outlined in IBC/UBC. This is not related to the seismic load generation. The reduced live load that you want to consider for your seismic weight calculations, would have to be defined through the appropriate factor separately, just like you have used 0.25 for the R2. 



Reply
  • You need to provide R1 1.0 R2 0.25 when defining the seismic weight.

    The reducible option results in reduction in the applied live load under certain conditions as outlined in IBC/UBC. This is not related to the seismic load generation. The reduced live load that you want to consider for your seismic weight calculations, would have to be defined through the appropriate factor separately, just like you have used 0.25 for the R2. 



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