I am engineer from Myanmar, Name is Ko Ko Lwin.

[Ko Ko Lwin]

Let me know Precast drain structural calculation and which type of material is more
economy?

 

[Dnyan Deshmukh]

Hello, Ko Ko Lwin, good to see you at forum.

welcome to civil engineers community.

you can ask for answers by posting a thread in ask question section, someone from same field will help you on the same.