online_scour_melville:   Pier and abutment scour using the Melville equation (1997)



ds = KyW KI Kd Ks Kθ KG

For abutment: KyW = KyL

For pier: KyW = Kyb


DESCRIPTION      [Example Problem]     [Examples from the Reference]     [Main Page]    

The calculator is set up to determine the depth of scour for a bridge featuring two (2) abutments, left and right, and one (1) pier. For the case of only one (1) abutment (either left or right), the user must repeat the data from Section 3 in Section 4. [Do not leave any blank data in either Sections 3 or 4]. For cases involving more than one (1) pier, the user must run the calculator for each pier, changing only the data of Section 7.

To run the calculator, the following information is required:

Abutments (Left and/or Right)

  • Length L, in m,

  • Shape,

  • Angle of alignment θ, and

  • Location (main or flood channel). For abutments that extend to the main channel, the width of flood the channel L*, in m, is required.


  • Length b, in m,

  • Width l, in m,

  • Shape,

  • Angle of alignment θ,

  • Location (main or flood channel);

  • Shape of cross-section (uniform or nonuniform). For nonuniform piers, the height z, in m, and the diameters D and D*, in m, are required.

  • Debris contamination occurrence. For piers subject to debris contamination, the debris thickness Td, in m, and diameter Dd, in m, are required.


  • Depth in the main channel y, in m,

  • Depth in the flood channel y*, in m,

  • Velocity in the main channel V, in m/s,

  • Velocity in the flood channel V*, in m/s,

  • Manning in the main channel n, and

  • Manning in the flood channel n*.


  • Median particle size d50, in m,

  • Geometric standard deviation of particle size distribution σg. If σg is greater than 1.3, the sediment is nonuniform and the maximum particle size dmax, in m, is required.