I have some a challenges to select the suitable structural system for administration building with large spans.
Could someone help me to suggest a suitable structural system since we have in the ground floor a hall room (12 m width variable , about 25 m length variable)( please , take a look to the attached captures) and its RC slab extended from all hall sides ( about 2m each side and one side about 4 m) while as in the first and second floor there is also hall (16 m width , 20m length also variable) which means the external column of the first and the second floor are supported on the cantilever of ground floor slab .
Knowing that the architect doesn’t want any internal columns inside the halls. it means that the span length of ground floor slab will be (12m short direction with the cantilever extension from both sides which are supported the column of upper floors .
My first attempt is to use RC frames (beams & columns) in ground floor then the external columns of upper floors will be supported on the cantilever beams of ground floor.
Which one do you think the best chose or do you have any other suggestions?
Knowing that the prestressed system is undesirable in this project. Only RC Structural systems.
Any advice or hint will be highly appreciated.