Load (\( Wc = C_d \cdot w \cdot B_d^2 \)):

Where:

• \( Wc \) is the total load on the conduit per unit length, in force per length (F/L).
• \( C_d \) is the load coefficient for ditch conduits.
• \( w \) is the unit weight of fill material, in force per cubic length (F/L³).
• \( B_d \) is the width of the ditch at the top of the conduit, in length (L).