Stormwater pipe connection to existing junction pit

[cyuan7]

Hi, I have a new 600 diameter stormwater pipe to be connected to an existing junction pit as shown in the figure below. I was recommended to put 50mm gout around annulus and cast 150mm grout collar around the branch pipe as well. Can someone give me some advices about this connection design? Like whether the bandage reinforcement or any dowels to existing structure are required, something like that. Thank you so much.

 

[robyengIT]

concrete shrinkage will cause leakage. Why not adopting a solution similar to the one shown

 

[CarlB]

We like using flexible segmented seals, such as link-seal, for fuel pipes through vault walls.

https://www.gptindustries.com/en/products/link-seal

For retrofit, concrete would be cored. For new, an oversized pipe sleeve cast in the wall.
Grout on the outside optional.