Question

The formula for discharge for three wells forming an equilateral triangle at distance B on side is given by ____________

(a) \(q_1=q_2=q_3= \frac{2πkb(H-h)}{log_e  \frac{R^2}{rB}} \)

(b) \(q_1=q_2=q_3= \frac{2πkb(H-h)}{log_e  \frac{R^3}{rB^2}}\)

(c) \(q_1=q_2=q_3= \frac{2πkb(H-h)}{log_e  \frac{RB}{r}}\)

(d) \(q_1=q_2=q_3= \frac{kb(H-h)}{log_e  \frac{R}{rB}}\)

This question was posed to me in an interview for internship.

This interesting question is from Well Hydraulics topic in portion Well Hydraulics of Geotechnical Engineering I

Answer 1

Right answer is (b) \(q_1=q_2=q_3= \frac{2πkb(H-h)}{log_e  \frac{R^3}{rB^2}}\)

To explain: The formula for discharge for three wells forming an equilateral triangle at distance B on side is given by,

\(q_1=q_2=q_3= \frac{2πkb(H-h)}{log_e  \frac{R^3}{rB^2}},\)

where, q1=q2=q3=discharge in wells 1 and 2 respectively

k=coefficient of permeability

b=aquifer thickness

R=radius of influence

r=radius of tube well

(H-h)=drawdown.