Sohaib Iqbal

dfetermine the soil pressure on the raft at wall side. consider it in calculations along with the retained soil pressure on the wall and check stability of wall against overturning and sliding.

apologies for late reply. i hope u all are doing well. basically i modelled a symmetric G+3 structure and performed linear dynamic analysis. after that i m trying to model with base isolators and then again will perform response spectrum analysis after considering 30 % damping. basically i have to observe reduction in base shear and change in time period bcz of rubber isolators.

respected engineers. i m working on base isolated structures. can anyone provide me the literature and examples for this?

Respected members! how outcomes differ when we do auto and manual mesh? which is most accurate and preferable?

if i assign a column of 5 ft wide it will take as solid mass. how to consider it hollow (as in case of inside stairs) in etabs?

can we model it on etabs like column?

dear waqas. can we assign strips L/4 at column?

Respected engineers. can anyone tell me that what is difference between 1st and 2nd order analysis? specially related to steel structures also.

because it is a easier way to get maximum deflections, moments and shear on the beam having pick up column.

can we consider loads on pick up column given by etabs then apply it as point load to design beam which is supporting pick up col?

i did. etabs designing it as a column but not designing the lower beam for this pick up column load.

on different steel percentages ultimate design section takes 30 to 80 % more load as compared to ASD design sections.

yes this is true. u can verify it by solving beam using these two methods. ASD method give large sections as compared to ultimate. but it is good in achieving servicibility criteria.i will try to give u an example solving by these two methods and thier comparison.

Respected engineers! can anyone elaborate the procedure to assign pick up column in etabs

sir Rana! will u please elaborate the procedure of checking torrosional irregularity and procedure to deal it. as u mentioned in ur post. Thanks