Question

For the use of vacuum method, the coefficient of permeability should be __________

(a) greater than 10^-3cm/s

(b) in the range 10^-3 to 10^-5cm/s

(c) less than 10^-5cm/s

(d) independent

The question was asked by my college professor while I was bunking the class.

My question is taken from Drainage and Dewatering in section Drainage and Dewatering of Geotechnical Engineering I

Answer 1

Correct choice is (b) in the range 10^-3 to 10^-5cm/s

To elaborate: For successful dewatering, the coefficient of permeability should be in the range 10^-3 to 10^-5cm/s where the vacuum method should be applicable. For coefficient of permeability greater than 10^-3cm/s, ditches and sumps are used.