How to cut the model a half and keep the circle hole shape

Support Modeling
1

Hello,
I have a question to cut the mesh half but keeping the circle hole do we have any way to keep it?

the org

cut it half

Thanks

2

yea could do it like that


3

Select the middle edge loop and press ctrl+shift+R to create 2 surrounding edge loops, confirm and then delete the middle edge loop. After that you can just add supporting edge loops like JA12 showed.