online_contraction_scour_clear_water:  Contraction scour under clear water conditions
using Laursen equation 1963
      
Laursen formula 1963

ys / yo = {[( Ku Q 2 ) / ( Dm0.667W 2)] 0.429 (1/yo)}  -  1

[ ys, yo, Q, Dm and W in any consistent units ]
[ Ku = 0.025 in SI units; Ku = 0.0077 in U.S. units ]

Reference:

Evaluating Scour at Bridges, FHWA Hydraulic Engineering Circular No. 18,
 Fifth Edition, 2012.

INPUT DATA:      [Description]     [Sample Input]

Select:      

Mean flow depth below the bridge, before scour yo :      

 

Discharge in the contracted section Q :      

 

Bottom width in the contracted section, excluding piers W :      

 

Median diameter of the bed material D50 :      

 

OUTPUT:

SI units (metric)

Contraction scour depth
under clear water conditions
ys :     

Press button to
or recalculate

  Your request was processed at  11:45:21 pm on August 19th, 2025   [ 250819  23:45:21 ].

Thank you for running   online_contraction_scour_clear_water   Please call again.   [180222 15:00]

Documents in Portable Document Format (PDF) require Adobe Acrobat Reader 5.0 or higher to view; download Adobe Acrobat Reader.