Well...we need to think about structural behaviour (see my attached) at first stage and the concern is about underground box which we were working for. I think this should not be any problem for future building on top using rigid foundation as usual in analysis (high rise will be done by future development party).
The structural behaviour will be much different doing as your suggestion method. At second stage, the underground structure box has already been deformed and the moments have been transferred from the wall to the roof before we build the building on top of the underground wall. If you connect the underground wall to the high rise wall, moment from underground wall (majority from soil pressures) will be transferred to the high rise which is completely wrong in structural behaviour.
This issue had been resolved using an alternative software to check the effects.
I'm happy with this communities found very useful to share ideas/knowledge.
The structural behaviour will be much different doing as your suggestion method. At second stage, the underground structure box has already been deformed and the moments have been transferred from the wall to the roof before we build the building on top of the underground wall. If you connect the underground wall to the high rise wall, moment from underground wall (majority from soil pressures) will be transferred to the high rise which is completely wrong in structural behaviour.
This issue had been resolved using an alternative software to check the effects.
I'm happy with this communities found very useful to share ideas/knowledge.