While designing a high-rise structure, I encountered an issue. The client requested the slabs to be designed as post-tensioned flat slabs. However, I am aware that flat slabs are not suitable for seismic-resistant design and should not be used in high seismic zones. Unfortunately, I couldn't find any direct clauses in the codes addressing this issue. If seniors can provide a reference from the code specifying not to design post-tensioned flat slabs in high seismic zones, it would be greatly appreciated.
