Check for punching shear in chamber walls

[symmetrical]

Due to water hammer load in pipe /flanged spigot pipe with central puddle flange/ should I check punching shear in walls?
If so, what should I consider as mean effective depth of the wall:
1) d = (wall thick. - flange thick.)/2– Concrete cover
or
2)d = (dy + dz)/2
dy,dz is the effective depths in the y and z directions of the control section;

Also, as the pipe body and its connections is rigid, will this force be resisted by one wall only/pipe clashes with two walls/?

THX