online_contraction_scour_live_bed:  Contraction scour under live bed conditions using modified Laursen 1960 equation Modified Laursen formula ys / y1 = ( Q2 / Q1 ) 0.86 (W1 / [W2) k1  -  ( yo / y1 ) [ yo, y1, Q and W in any consistent set of units ] [ S1 in m/m or ft/ft ] [ T in °C or °F ] [ D50 in mm or ft ] Reference: Evaluating Scour at Bridges, FHWA Hydraulic Engineering Circular No. 18, Fifth Edition, 2012. INPUT DATA:      [Description]     [Sample Input] Select:       SI units (metric) U.S. Customary units Mean flow depth below the bridge, before scour yo :         Warning: Undefined variable $depthunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 398 Mean flow depth upstream of the bridge y1 :         Warning: Undefined variable $depthunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 404 Discharge upstream of the bridge (only in the main channel) Q1 :         Warning: Undefined variable $dischargeunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 410 Discharge in the contracted section Q2 :         Warning: Undefined variable $dischargeunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 416 Bottom width in the section upstream of the bridge W1 :         Warning: Undefined variable $widthunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 422 Bottom width in the contracted section, excluding piers W2 :         Warning: Undefined variable $widthunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 428 Energy slope in the main channel upstream S1 :         Warning: Undefined variable $slopeunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 434 Median diameter of the bed material D50 :         Warning: Undefined variable $dfiftyunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 443 Select water temperature T :       0°C  /  32°F 20°C  /  68°F 40°C  /  104°F OUTPUT: Warning: Undefined variable $unitsystems in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 483 SI units (metric) Warning: Undefined variable $temperature in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 487 Water temperature T: 0°C Contraction scour depth under live bed conditions ys :    Warning: Undefined variable $scourdepth in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 529 Deprecated: substr(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 529   Warning: Undefined variable $depthunits in /var/www/html/ponce/onlinecontractionscourlivebed.php on line 529 Press button to or recalculate   Your request was processed at  10:55:06 pm on April 3rd, 2025   [ 250403  22:55:06 ]. Thank you for running   online_contraction_scour_live_bed   Please call again.   [180222]