Question

For purely rigid streams, the foundation of the bridge substructure is taken above the bed.

(a) True

(b) False

I got this question by my school teacher while I was bunking the class.

This intriguing question comes from Culverts Construction topic in chapter Culverts and Small Road Bridges Construction of Irrigation Engineering

Answer 1

Right option is (b) False

For explanation I would say: From theoretical considerations, there will be no scouring and the foundation of the bridge sub-structure will have to be taken below the bed by a nominal amount not by scour considerations. It is done so as to provide sufficient grip on them.