Auto Seismic Analysis in STAAD PRO

Hi Sanjay,

No, it is not necessary to add Joint Weights in a seismic definition.  The joint weight option is provided for instances where it may be convenient to use.  One example that comes to mind is modeling the weight associated with connection material used in large gusset/bracing connections. 

Fortunately, the procedure for applying seismic loads is the same regardless of the material/construction type.

Note that a new build of STAAD.Pro is now available for downloading from the SELECT site.  It goes by the name STAAD.Pro V8i SELECT Series 1 and has the build number 20.07.06.23.

Cheers,

Chris

 

Dear Chris,

Thanks for your reply to my querry, I am attaching a STAAD file of seismic analysis done by me, please check, If I have done it correctly.

Thanks for your help,

regards,

Sanjay

Hi Chris, Thanks for your information. Could you update my STAAD Input file with P-Delta Analysis Parameter? 

thanks and best regards,

Sanjay 

 

Sanjay,

I made some modifications to the attached version of your model.  They include a PDELTA analysis command, converting your LOAD COMB statements to REPEAT LOADs, adding PERFORM ANALYSIS and CHANGE commands after your two seismic load cases, and inserting the SET NL command to specify the total number of primary load cases, now that this has become a "multiple analysis" model.

This should give you a good start on incorporating a technically correct PDELTA analysis.

Cheers,

Chris

Dear Chris,

Thanks for the update in input file. I ran the file, but its giving syntax error in floor weight, when I ran the analysis, it shows one error:

187. PDELTA 35 ANALYSIS SMALLDELTA

*** ERROR *** ABOVE LINE CONTAINS ERRONEOUS DATA.
 what could be the reason?

regards,

Sanjay

 

My pleasure Sanjay.  There are a couple of things to look for to diagnose the Error. 

First, be sure you are running the most current version, because no errors are reported in the most current version.  If your service agreement is current, you can download and install the latest version from the website.  If you are running a version earlier than 20.07.xx.yy, then it is probably not recognizing the SMALLDELTA portion of the PDELTA command.  Just try deleting that one word, save, and see if that will run.

Next, be aware that the FLOOR load command will always produce a Warning, whether or not there is a problem with your particular use of the command.  The Warning is there to remind us that the algorithm used to apply FLOOR loads can produce unexpected results if it is applied to an area that includes and inside corners.  It is always best to visually inspect the loads that are actually applied by the FLOOR load command to ensure that they are as expected.  If you ever have any trouble with it, the best thing to do is to break it into more commands that each apply to smaller areas within the model, and to make sure that each of the smaller areas is convex in shape.

Cheers,

Chris

Thanks Chris, I am using Staad Pro 2006, probably the commands are not supported in this version.. I will check with the latest updates. regards, Sanjay

Thanks Chris, I am using Staad Pro 2006, probably the commands are not supported in this version.. I will check with the latest updates. regards, Sanjay