Ayesha

Also, see this:

Normally the connection between brick wall and slab will need to be detailed. It can be a shear connection with an angle transferring shear from slab to brick wall and you can model this arrangement as pinned or your can provide rebar. See attached.

The building framing is complex. If L2 is basements, irregularities need to be calculated for level above basement. If you keep the framing as is, from L2 to L8 should be single story, for global structure check and for each individual tower I would do local check between each story as well. This is based on my engineering judgement. I don't have any references detailing this.

Normally there isn't a hard requirement to mesh frame elements if they are not supporting area elements. I believe there is a setting on number of internal sections that matters more for frame sections as it reports the number of points along length were results are calculated. You can always look at deformed shape to see if there is something wrong with the model.

The building is really irregular. I would suggest isolating different sections of building if it is possible considering building envelope and architectural plans. For concrete buildings, the normal rule of thumb that I have seen out of handbooks in 180 feet. You can also refer to ACI 224.3R to further details. Hope that helps.

In my opinion the section applies to all type of buildings. You can read ASCE and see applicability from there as well.

I think you forgot to attach the report or provide a link for it.

what is your question?

There could be number of reasons for this. The first step in my opinion will be to ensure if the file from ETABS has been correctly exported to SAFE. Please follow the following link and ensure that step is done correctly and try again. https://wiki.csiamerica.com/display/safe/Import+ETABS+into+SAFE+FAQ

There is some additional information on Mass Irregularity in Appendix F and Strong Column/ Weak Beam discussing in Appendix G of the document.

Welcome to the forum. You have an interesting background. Sure, if you can provide details and plans then other people can provide some suggestions.

Point spring I assume you are referring to single spring. Single spring represents single pile.

i am not sure if there is an option in ETABS to do it. I would suggest to export reactions to excel and check the reactions against max tensile and compressive capacity of pile.

This is an interesting situation. I also agree with @Ebeid that releasing beams wouldn't be a wise thing to do as it will also effect lateral force resisting system. The frist thing that I would suggest would be to sharpen the pencil and see if the loads have any contingency and remove that contingency from loads and checking if the provided reinforcement in the column works. If that doesn't work, you can add more columns per bay to make things work but it would require new foundations.

There are different way depending upon the risk category of the structure. Pile capacity of concrete is one things and geotechnical capacity is another. The best way would be to do a pile load test on this pile group. Geotechnical consultants normally do such test and it helps verify capacity of existing piles both structurally and geotechnically. For concrete strength, like you said core testing is one way. I am not familiar with GPR for strength testing of concrete piles. I have seen a lot of results of GPR surverys to find buried lines but nothing to determine strength. Hope this helps.