Bulletin 1486, U. S. Dept. of Agriculture 
Plate 1 
Examples of Damage to Bridge Structure by Erosion 
A.— Failure of wing wall due to improper design and location 
B. — Undermined wing wall, primarily the result of poor location 
Examples of Different Foundation Conditions 
C— Railroad bridge over the Columbia River at Celilo, Oreg. This is a good example 
of site selection based on foundation conditions. Every pier is on exposed solid 
rock, a condition not encountered at any other crossing within the zone of selection 
D.— Double wall puddle dam construction on Oregon City bridge. This type of con- 
struction was made necessary by solid rock foundation without overburden and 
at too great a depth to permit the use of a simple sack dam 
