I am designing a 1m thick raft slab and the drainage guys have thrown in 100mm diameter cast in pipes all over the raft. See Attached images 1 & 2. Wondering how this will affect the shear in the raft and how i can go about calculating required shear reinforcement for a) the column and b) the pipes. I have read the presence of the pipes can be ignored however this doesn't seem right to me especially when columns are surrounded by pipes. Any feedback or pointers to get me in the right direction would be greatly appreciated. the Raft has an H20-150 Basic Matt throughout T&B.