Civil Engineering UPSC PYQ 2016

Discuss the principle of recuperation test of an open-well and derive equation for the specific capacity K_s per unit Well area.

Design the bottom diameter of a dug Well in fine sand region, to obtain 10 litres/second of yield, under depression head of 2.5 m. The value of K_s = specific capacity per unit area may be taken as 0.6/hour.

Three wells A, B and C, tap the same horizontal aquifer. The distances AB = 1200 m and BC = 1000 m. The Well B is exactly south of Well A and Well C lies to the west of Well B. Following are the ground surface elevation and depth of water below the ground surface in the three wells: [2016]

Well A: Surface Elevation = 200.00 m, Depth of water table = 11.00 m

Well B: Surface Elevation = 197.00 m, Depth of water table = 7.00 m

Well C: Surface Elevation = 202.00 m, Depth of water table = 14.00 m

Determine the direction of ground water flow in the aquifer in the area ABC of the wells.