From analysis (typical for 3×2 box with 0.25m thickness):
Design of concrete structures, covering strength and serviceability limits. box culvert design calculations eurocode 2021
Before starting calculations, several input parameters must be established to ensure the structure meets both hydraulic and structural needs. From analysis (typical for 3×2 box with 0
$$M_Ed \leq M_Rd = f_cd \cdot b \cdot x \cdot (d - 0.4x)$$ box culvert design calculations eurocode 2021