The initial piezometric head in a confined aquifer, which has a thickness of 11.6 m, is 85.7 m above sea level. A well with a radius of 0.5 m pumps at a constant rater 3 of 1,240 m3 /day. After the cone of depression has achieved equilibrium (i.e., steady state), the piezometric heads at two observation wells 40 m (well 2) and 95 m (well 1) from the pumping well are measured as 78.9 m and 83.4 m above sea level, respectively. - determine the total well losses in and around the pumping well if the observed head in the pumping well during equilibrium is 46.6 m. - A tracer was injected into well 1. We find it takes 50 days for the injected dye to travel to the well 2. Estimate the aquifer porosity (n).

The initial piezometric head in a confined aquifer, which has a thickness of 11.6 m, is 85.7 m above sea level. A well with a radius of 0.5 m pumps at a constant rater 3 of 1,240 m3 /day. After the cone of depression has achieved equilibrium (i.e., steady state), the piezometric heads at two observation wells 40 m (well 2) and 95 m (well 1) from the pumping well are measured as 78.9 m and 83.4 m above sea level, respectively. - determine the total well losses in and around the pumping well if the observed head in the pumping well during equilibrium is 46.6 m. - A tracer was injected into well 1. We find it takes 50 days for the injected dye to travel to the well 2. Estimate the aquifer porosity (n).

Fundamentals of Geotechnical Engineering (MindTap Course List)

5th Edition

ISBN:9781305635180

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter6: Hydraulic Conductivity

Section: Chapter Questions

Problem 6.9P

See similar textbooks

Similar questions

An artesian aquifer 5 m thick with a piezometric surface 65 m above the bottom confining layer is being pumped by a fully penetrating well. The aquifer is a mixture of sand and gravel. A steady-state drawdown of 7 m ・ s−1 is observed at a nonpumping well located 10 m away. If the pumping rate is 0.020 m3 ・ s−1, how far away is a second nonpumping well that has an observed drawdown of 2 m?
A well is fully penetrated into a 27 m thick layer of sand which is underlain by a rock layer below the static water table. After 24 hours of pumping at 50 liters per second, the water level in an observation well at a distance of 0.10 km from the test well is lowered 50 cm. At another test well located 5000 cm from the test well, the water level dropped by 1000 mm. 1. Evaluate the coefficient of permeability (K) in cm per day? 2. If K 1.15 cm/sec, what should be the rate of discharge (q) in ( lit/sec)?
An experiment was conducted to determine the hydraulic conductivity of an artesian (i.e., pressured confined aquifer). The piezometric heads at two points 150 m apart were found to be 60 m and 56 m above a datum (reference level). A tracer injected into the first piezometer was observed after 20 hours in the second well. A test on porosity of a sample of the aquifer shows that α = 24%. a) What are the Darcy velocity (q) and seepage velocity (v) of groundwater flow. b) What is the conductivity of the aquifer?
A 1.15 m diameter pumping well penetrates vertically through a confined aquifer which is 42 m thick. While pumping at a rate of 2880 m3/day, the drawdown in an observation well 20 m away is 2.0 m. In another observation well, that is located 60m away, the drawdown is 0.45m. Initial piezometric level is 52m above the datum. Determine: The approximate head in the pumping well for steady state condition?The approximate drawdown in the pumping well ? The transmissivity of the aquifer ? The radius of influence of the pumping well?
Q-26: A 0.5 m diameter well fully penetrates an unconfined aquifer whose bottom is 150 m below the undisturbed groundwater table. The water is pumped out from the well at a constant rate of 0.1 m³/s. After equilibrium is reached, the drawdown observed in two observation wells at radial distances of 10 m and 50m are respectively 10 m and 5 m. Determine (i) The coefficient of permeability (in m/s) (ii) The drawdown in the well (in m)
A 1.15 m diameter pumping well penetrates vertically through a confined aquifer which is 42 m thick. While pumping at a rate of 2880 m3/day, the drawdown in an observation well 20 m away is 2.0 m. In another observation well, that is located 60m away, the drawdown is 0.45m. Initial piezometric level is 52m above the datum. Determine: A.The approximate head in the pumping well for steady state condition B.The approximate drawdown in the pumping well C.The transmissivity of the aquifer D.The radius of influence of the pumping well
Question 2 * A well with a diameter of 0.6 m is constructed in a confined aquifer. The sand aquifer has a uniform thickness of 15 m, overlain by an impermeable layer with a depth of 35 m. A pumping test was conducted to determine the coefficient of permeability of the aquifer. The initial piezometric surface was 15 m. below the ground surface datum of the test well and observation wells. After water was pumped at a rated of 13 liters/sec for several days, water levels in the wells stabilized with the following drawdowns, 6.4 m in the test well, 3.7 m in the observation well 10 m from the test well, and 2.4 m in the second observation well at a distance of 30 m. From these data: o Find the depth of the water in the test well Calculate the permeability of the aquífer.
An artesian well is pumping water from a confined aquifer (thickness = 12 m) at a flow rate of 0.024 m3/s. The piezometric surface is 50 m above the bottom of the confining layer. In two monitoring wells (no pumping) located 15 m and 150 m away from the pumping well, steady-state drawdowns of 4 m and 1 m are observed, respectively. What is the intrinsic permeability of the aquifer (assuming the groundwater temperature is 15 ).
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.
The thickness of a horizontal, confined, homogeneous, isotropic aquifer of infinite areal extent is 30m. A well fully penetrating the aquifer was continuously pumped at a constant rate of 0.1 m³/s for a period of 1 day. The drawdowns given in the table below were observed in a fully penetrating well 90 m from the pumping well. Compute the transmissivity and the storativity by using: a) the Theis method of log-log matching. b) the Cooper-Jacob method of semi-log plotting. [For Part a), you have to first use attached Table to plot the values of W(u) versus 1/u on a log-log graph in the range of 10-9
A confined aquifer of 15 m constant thickness is sandwiched between two aquicludes as shown in the figure. (not drawn to scale) Piezometer P 55.2m Piezometric Surface m Aquiclude Aquifer Aquiclude L = 2500m Piezometer Q TTTTTR 34.1m The heads indicated by two piezometers P and Q are 55.2 m and 34.1 m, respectively. The aquifer has a hydraulic conductivity of 80 m/ day and its effective porosity is 0.25. If the distance between the piezometers is 2500 m, the time taken by the water to travel through the aquifer from piezometer location P to Q (in days, round off to 1 decimal place) is
A 1.15 m diameter pumping well penetrates vertically through a confined aquifer which is 42 m thick. While pumping at a rate of 2880 m3/day, the drawdown in an observation well 20 m away is 2.0 m. In another observation well, that is located 60m away, the drawdown is 0.45m. Initial piezometric level is 52m above the datum. Determine: The radius of influence of the pumping well?