Abutment Scour In HEC-RAS
Abutment Scour In HEC-RAS
(OP)
I'm working in HEC-RAS on a scour research project. My issue is that the values I am getting for abutment scour are artificially high. From what I understand, many DOT's ignore HEC-RAS's abutment scour outputs because in almost all cases HEC-RAS grossly overestimates how deep the scour will be. I have tried adjusting the deck in order to line the bottom of the channel to reduce the vertical scour, but HEC-RAS does not allow you to do that. Anyone who has more experience in HEC-RAS ever dealt with this before? If so, how did you solve the problems you ran into with overestimation and come to a reasonable solution?





RE: Abutment Scour In HEC-RAS
RE: Abutment Scour In HEC-RAS
RE: Abutment Scour In HEC-RAS
there are DOTs not allowing HEC-RAS/HEC-18 results since the result is always too off. An example is Louisiana LADOTD -check out LADOTD hydraulic manual of 2011 Page 11-8. Another one is TxDOT. In TxDOT geotech manual Page 5-15, it reads that "Do not calculate abutment scour because none of the equations to date yield acceptable results. Protect abutments against potential scour through use of a flexible revetment, where possible."
TxDOT even uses a reduction factor of 0.5 to HEC-18 pier scour calculation under cohesive materials condition since it is know that HEC-18 results are way too conservative especially for cohesive soil.