since the ramp in my case are inclined to specified degree , i want to ask that is it possible to design the building for EQ forces ? i am designing as per is 1893-2002 and i have tried by member weight option it mean that i have transferred the slab forces on the adjacent beams . But analysing it is showing some error. what should i do ?
Please Upload your file here. As far as this kind of model is concern one can define the Eq. Weights on the Structure and it works fine to generate the Seismic Forces..
I feel that for this type of structure all loads including self weight have to be converted into Joint Weght and applied to the joints to generate seismic load in the lateral direction. The usual format for loading may not work for inclined floor for generating EQ load in lateral direction.
Don’t know why Mr.Sharma thinks that STAAD cannot generate earthquake forces on an inclined surface.
If the beam or slab is split up into several segments, the gravity load + the external weight acting on those segments or elements can be applied using the member load or element pressure load options, depending on the entity they are modeled as. Those loads will get converted internally during the analysis to lumped weights at the nodes of those entities. At each node where a weight gets lumped, a lateral load will be generated. You do not need floors in a structure in order for lateral loads to be generated.
Thank you Mr. Lose for your valuable contribution and clarifying my doubts.
One more thing that I observe from the file posted by Mr. Chavada that he has not applied Live load or Dead Load on the inclined ramp. I suppose this has been inadvertently left. Please look into the file from your view and post your comments.
I agree that selfweight has been omitted from the model he has attached. That and any other loads that have been omitted need to be included in the model.
this is the final model. verify it and say whether it is right or not.
Mr. sklose i have tried the said option of member load but it showed the error in generating the EQ forces. then i tried the plate load with plate load specification then the staad was able to generate the EQ forces.
Himmatlal Chavda,
To the best of my knowledge, the MEMBER WEIGHT feature works quite well. When you provide the seismic weights under "DEFINE 1893 LOAD", you should use the syntax MEMBER WEIGHT, not MEMBER LOAD. If you typed the data using the editor, a mistake could have crept in unbeknownst to you. If you assign it using the graphical tools, the program generally does it without any errors.
In any case, attached is a model which shows the usage of that command.
If you are convinced that there is an error in the program, you ought to upload the model that reveals the error, or send it to the STAAD support people at Bentley.