scour 1

[dsheth]

For geotechnical purposes, is there a procedure to "estimate" the scour depth for a certain stream or branch? The reason for this question is that there is requirement for geotechnical reports to determine the depth of scour. However, a scour analysis has not been performed and will not be performed.

 

[PECPESC]

Typically scour occurs at bridges or other structures.
The Federal Highway Administration Hydraulic Engineering Circular No. 18 (HEC-18) is titled "Evaluating Scour at Bridges". The program HY-9 performs calculations based on HEC-18.
They also have Hydraulic Engineering Circular No. 20 (HEC-20)titled "Stream Stability at Highway Structures"

Web site:

http://www.fhwa.dot.gov/

Software may be available from McTrans, Univ. of Fla.

http://mctrans.ce.ufl.edu/

Hope this helps.

 

[koodi]

Take care, scour is the most common cause of failure!

 

[LHA]

HECRAS has an analysis based on HEC 18. It depends largely on aggregate size, which you will have to state (and then stand by when the reviewer thinks the D50 is a few mm different than your interpretation). Other than that, it only requires input about culvert alignment and construction and sectional topography, which should be available from the plans and profiles.

 

[gbam]

Without conducting a full scour analysis one can calculate the equilibrium slope of the channel to estimate longterm degradation. This will allow you to determine the condition of the stream, either agrading or degrading. Then as posted above HEC18 is a quick way to estimate scour at structures.

Good Luck