Question
What is consideration in selecting an orientation of wing walls in designing of bridge abutments?
Answer
There are three familiar arrangements of wing walls in bridge abutments based on Dr. Edmund C Hambly in1979-
(i) Wing walls parallel to abutments -
This is simplest and shortest time to make but is not most economical design. This design has plus points that it has least disturbance to active slope embankment.
(ii) Wing walls at an angle to abutments -
This is most economical designing among three options in terms of material rate.
(iii) Wing walls perpendicular to abutments -
Though it is not most economical design, wing walls provide a continuous alignment with bridge decks that provide supports to parapets. However, they reason disturbances to adjoining structures and value services during construction. Moreover, if bridge is curved, wing walls could hinder the road curvature.
One other hand, when wing walls are structurally connected to an abutment, after that structural gain is able to be taken by steadiness of box structure.