UESTION 13 1. A 40 cm well completely penetrates an unconfined aquifer of saturated depth 40 m. After a long period of pumping at a steady rate of 0.025 m³/s, the drawdown in two observation wells 20 m and 80 m from the pumping well were found to be 4.0 m and 2.0 m respectively. Determine the drawdown at the well. Round off to two (2) decimal places, in m

UESTION 13 1. A 40 cm well completely penetrates an unconfined aquifer of saturated depth 40 m. After a long period of pumping at a steady rate of 0.025 m³/s, the drawdown in two observation wells 20 m and 80 m from the pumping well were found to be 4.0 m and 2.0 m respectively. Determine the drawdown at the well. Round off to two (2) decimal places, in m

Principles of Geotechnical Engineering (MindTap Course List)

9th Edition

ISBN:9781305970939

Author:Braja M. Das, Khaled Sobhan

Publisher:Braja M. Das, Khaled Sobhan

Chapter7: Permeability

Section: Chapter Questions

Problem 7.22P: Refer to Figure 7.24. The following data were collected during the field permeability measurement of...

See similar textbooks

Similar questions

Refer to Figure 7.24. The following data were collected during the field permeability measurement of a confined aquifer using a pumping test. Determine the hydraulic conductivity of the permeable layer. Use Eq. (7.49). Thickness of the aquifer, H = 4.5 m Piezometric level and radial distance of the first observation well: h1 = 2.9 m; r1 = 17.8 m Piezometric level and radial distance of the second observation well: h2 = 1.8 m; r2 = 8.1 m Rate of discharge from pumping, q = 0.5 m3/min
A 1-m diameter well penetrates vertically through a confined aquifer 30m thick. When the well is pumped at 113 m^3/hr, the drawdown in a well 15m away is 1.8m, in another well 50m away, it is 0.50m. What is the approximate drawdown in the pumped well?
A well fully penetrates a 60m thick confined aquifer. After a long period of pumping at a constant rate of 0.1 m3 s-1, the drawdowns at distances of 50 and 150 m from the well were observed to be 5 and 2 m, respectively. What is the transmissivity of the well? Be sure to include a diagram with your written work submission.
b) A 30-cm well fully penetrates an unconfined aquifer of saturated depth 25 m. When a discharge of 2100 lpm was being pumped for a long time, observation wells at radial distances of 30 m and 90 m indicated drawdown of 5 and 4 m respectively. Estimate the coefficient of permeability and transmissibility of the aquifer. What is the drawdown at the pumping well?
The static level of water table in an unconfined aquifer was 30 m above the underlying impermeablestratum. A 150 mm diameter well, penetrating the aquifer to its full depth, was pumped at the rate of20 liters per second. After several weeks of pumping, the drawdown in observation wells 20 m and 50m from the well were 3.5 m and 2 m respectively, and the observed drawdowns were increasing veryslowly (B.Sc., DU, 2012).a) Assuming equilibrium conditions, estimate the hydraulic conductivity and transmissivity of theaquifer.b) Estimate the drawdown just outside the pumped well.c) What will be the yield of a 300 mm diameter well which will produce the same drawdowns justoutside the well and at the 50 m distance observation well in (2)? What would be the drawdown at anearer observation well?
A 2‐ft diameter well penetrates vertically through a confined aquifer 50 ft thick. When the well is pumped at 500 gpm, the drawdown in a well 50 ft away is 10 ft and in another well 100 ft away is 3 ft.(a) What is the approximate head in the pumped well for steady‐state conditions, and what is the approximate drawdown in the well?(b) Compute the transmissivity. Take the initial piezometric level as 100 ft above the datum.
A 30 cm well completely penetrates an unconfined aquifer of saturated depth 40 m. After a long period of pumping at a steady rate of 1500 lpm, the drawdown in two observation wells 25 and 75 m from the pumping well were found to be 3.5 m and 2.0 m respectively. a.) Determine the transmissivity (m^2/s) of the aquifer. b.) What is the drawdown (m) at the pumping well?
Q3. A 200 mm diameter well which fully penetrating a confined aquifer of thickness 25 m is pumped at a constant rate of 2000 m3/day. The steady state drawdown in the well is 8 m and the drawdown in a piezometer 100 m from the well is 1.4 m.(a) Ignoring well losses, calculate the transmissivity of the aquifer, the hydraulic conductivity of the aquifer material and the radius of influence of the well.(b) Repeat the calculation for an unconfined aquifer with saturated thickness 25 m
A 30 cm diameter well penetrates vertically through an aquifer to an impermeable stratum which is located 18.0m below the static water table. After a long period of pumping at rate of 1.0m^3/min, the drawdown in test holes 14m and 40m from the pumped well is found to be 2.62m and 1.50m respectively. What is the coefficient of permeability of the aquifer? Express in meters per day. What is its transmissibility? Express in cubic meters per day per meter. What is the drawdown in the pumped well?
A 30 cm well penetrates an unconfined aquifer of saturated depth of 25m. When a discharge of 2100 lpm was being pumped for a long time, observation wells at radial distances of 30m and 90m indicated drawdown of 5m and 4m, respectively. Estimate the coefficient of permeability and the drawdown at pumping well.
A well is constructed to pump water from a confined aquifer. Twoobservation wells, MW1 and MW2, are constructed at distancesof 100 m and 1000 m, respectively. Water is pumped from thepumping well at a rate of 0.2 m3 /min. At steady state, drawdowns is observed as 2 m in MW2 and 8 m in MW1. Note that drawdownis greater (8 m) for well MW1 located closest to the pumping well.Determine the hydraulic conductivity K and transmissivity T if theaquifer is 20 m thick
A confined aquifer has a thickness of 85 ft. An 86-in diameter well drilled to the bottom of the aquifer, as shown in fig 3-10, if the hydraulic conductivity of the aquifer is 10 ft / day, and if water is originally 170 ft deep in the well, calculate approximately the maximum rate of flow that can be pumped from the well without dewatering any part of the aquifer. Assume 1000 ft reasonable value for the radius of influence. What will be the average velocity ( Darcy velocity ) of flow in the aquifer at a distance 20 ft from the center of the well?