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Hello Engineers So I'm having this 7 story building on a sloped land, the occupied levels will be from zero level (Street level) to +3 level , 4 residential stories. the bottom three -3,-2,-1 are being constructed on three levels in order to avoid drilling and any excavation work, considering that building is on hard rock (top of a mountain), and it will be very costly in order to do so. there are many problems that I have Encountered, and I truly need the help from you guys. -the first one is that the occupied stories's structural system is a load bearing walls, rested on Dual system of shear walls and moment resisting frames(the bottom three stories) and now I am Having soft stories , is it correct to model brick walls in the model, as they participate in their stiffness, and if modeled and still there is a soft story, what should I do? as you can see from the figures, the story geometry, specially -3,-2, is way less than that upper floors, and I can't go much deeper downwards in order to increase the number of vertical element. -in the 3 bottom levels+ zero level, Center of mass and center of rigidity are way far from each other, "way more than 5%L", which eventually causes Extreme torsional irregularity, More than 1.4 max drift to avg displacement values are obtained when checked to static load cases, I even Added the two shear walls at the top of the plan on order to pull center of rigidity closer to center of mass, But still, No point of that. I once heard from an Engineer, that Even if the building has torsional irregularity, when you design Piers and columns using Etabs, the program already takes care of that irregularity, as much as I want to believe that, But I think that torsional irregularity is a matter of a hole building geometry and behavior Plus it's a code requirement , and increasing the area of reinforcement won't help, what's right and what's wrong ? -is there any other checks that I should Do ? , is there any recommendations/Suggestions ? **I would truly Appreciate Your help. thank you.

Hello everyone!! I have tried to understood the every step of etabs analysis for simple two story irregular building by manual calculation. But i got stuck when the centre of rigdity and the amount of torsion does not match. How can we calculate these things manually? . As well as i want to know further about the distribution of this torsion to frame member. Thanks

i hv little query about the centre of rigidity... is centre of rigidity is independant of loading..?? if yes then how material non linearity or second degree analysis affects the centre of rigidity....