Question

The relation between the scour depth (R) and Regime scour depth (Re) for an alluvial river having regime width (W) and contracted width (B) is given by ______

(a) R = Re (W/B)^0.61

(b) R = Re (B/W)^0.61

(c) R = Re (W/B)^0.33

(d) R = Re (W/B)^0.33

I had been asked this question in a job interview.

I want to ask this question from Culverts Construction topic in section Culverts and Small Road Bridges Construction of Irrigation Engineering

Answer 1

Correct answer is (a) R = Re (W/B)^0.61

For explanation: For purely alluvial streams, the Lacey’s scour depth (R) is given by R = 1.35 (q^2/f)^1/3 where q is the discharge intensity per unit width of the stream at the bridge site.

The value of Lacey’s regime scour depth (Re) is given by R = Re (W/B)^0.61.