Question

In a syphon aqueduct provided with a pucca bottom floor, the uplift will occur on __________

(a) the roof slab

(b) the bottom floor

(c) both the roof slab as well as the bottom floor

(d) nowhere since the flow is free in the canal as well as in the drainage channel

This question was addressed to me in unit test.

This interesting question is from Types of Cross Drainage Work in section Cross Drainage Work of Irrigation Engineering

Answer 1

Right answer is (b) the bottom floor

To explain: The uplift pressure on the floor of the aqueduct is caused due to seepage of water from the canal to the drainage and the sub-soil water table in the drainage bed. The drain bed of the aqueduct is generally depressed and provided with the pucca floor.