QUESTION 12 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 hydraulic conductivity of the aquifer. Round off to two (2) decimal places, Fill in the blank_x 105 m/s

QUESTION 12 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 hydraulic conductivity of the aquifer. Round off to two (2) decimal places, Fill in the blank_x 105 m/s

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

B- A 20cm diameter well penetrates fully a confined aquifer of thickness 25m .when the well is pumped at a rate of 200 liters/ minute the drawdown in two observaƟons wells located at 10m and 100m distance from center of well are found to be 3.5m and 0.05 m respectively .calculate the hydraulic conductivity of the aquifer and the radius of influence and the drawdown in the well.?
In an artesian aquifer of 8m thickness , a 10cm diameter well is pumped at a constant rate of 100 liter/minute . The steady state drawdown observed in two wells located at 10m and 50m distances from the center of the well are 3m and 0.05m respectively , compute the (Kb) and hydraulic conductivity of the aquifer ?
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?
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?
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?
A well with a 0.25-m diameter fully penetrates an unconfined aquifer that is 20 m thick. The well has a discharge of 0.015 m ・ s−1 and a drawdown of 8 m. If the flow is steady and the hydraulic conductivity is 1.5 × 10−4 m ・ s−1, what is the height of the piezometric surface above the confining layer at a site 80 inches from the well?
Hydrology engineering Q.5. In an artesian aquifer of 8m thickness , a 10cm diameter well is pumped at a constant rate of 100 liter/minute . The steady state drawdown observed in two wells located at 10m and 50m distances from the center of the well are 3m and 0.05m respectively , compute the (Kb) and hydraulic conductivity of the aquifer ?
A pump well is dug through a confined aquifer having a thickness of 32 meters. The piezometric surface of the aquifer is 18 meters measured from the top impermeable layer. The first observation well is 75 feet directly west of the pump well and the second observation well is 75 feet directly north of the first observation well. Determine the hydraulic conductivity of the aquifer if it supplies a discharge of 10 liters per second and the drawdown of the observation wells are 13 feet and 23 feet.
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?
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 confined aquifer has a source of recharge as shown in the figure. The hydraulic conductivity of theaquifer is 40m per day and its porosity is 0.25. The piezo metric head in the two wells with 13.25 mapart are 65m and 60m respectively from a common data. The average thickness of the aquifer is25m and the average width is 4km.a. Compute the rate of flow through the aquifer in cu.m per day.b. Compute the seepage velocityc. Compute the time of travel from the head of the aquifer to a point 4 km downstream in days.
A well of 0.3m radius in a confined aquifer was pumped at a steady rate of 30 li/s from a fully penetrating well. when the well level remained constant at 85.5m above datum, the observation well (borehole) constructed at a distance of 10m recorded a water level of 86.5 m. The aquifer thickness is estimated at 20 m. Determine the hydraulic conductivity of the aquifer around the well (in m/day). What is the transmissivity of the aquifer in m2/day?