Foundation Design For Scour
Foundation Design For Scour
(OP)
I am trying to better understand the foundation design requirements for Scour.
According to the IDOT manual you would design your foundation based on Q100 flood and "check" the design based on Q500. By "check" they mean using a reduction factor = 1.0.
My questions are:
Is this correct? My example uses IDOT, but I would be glad to hear general comments.
If a flood level less than Q500 causes a water topping event, would you use this as your check? What limit states need to be checked in this event?
Thanks!
According to the IDOT manual you would design your foundation based on Q100 flood and "check" the design based on Q500. By "check" they mean using a reduction factor = 1.0.
My questions are:
Is this correct? My example uses IDOT, but I would be glad to hear general comments.
If a flood level less than Q500 causes a water topping event, would you use this as your check? What limit states need to be checked in this event?
Thanks!





RE: Foundation Design For Scour
You can read in section 2.6.4.4.2 about if you should use the overtopping flood versus the 100 year or 500 year event. For the design flood it is supposed to be the more severe of the 100 year or overtopping. The check flood can be the 500 year event or an overtopping event of lesser recurrence interval. My take on the check flood is you are trying to prevent the bridge from being washed away in a 500 year event.