Download FINAL APPENDIX A WITH PICTURES C REVISED

This table is used in the following manner. The user reviews the site conditions or
descriptors which are present at the bridge site under consideration, and selects the factor
in the table that best describes the crossing site under consideration. The engineer may
select a higher safety factor if it is considered necessary to reflect a high risk crossing
site.
Please note that the current scour evaluation procedure described in Chapter 11 of the
Manual directly calculates the potential effects of both channel migration and
degradation. This calculation serves to decrease the need for reliance on a safety factor to
account for lateral channel movement and degradation.
APRIL 2011
Page 69