A single pumping well, with a flow rate of 250 gpm, fully penetrates a confined aquifer. The aquifer has a saturated thickness of 110 ft, hydraulic conductivity of 20 ft/d, and storage coefficient of 0.00050. Due to outcropping of the aquifer, a no-flow zone exists 200 ft east of the pumping well and extends as a straight line to both north and south. An observation well is located 100 ft south and 120 ft east of the pumping well. Drawdown in feet at the observation well at time t=1, 5, 10, 20, 30, 40, 60, 80, 100, 120, 240, 480, 600, 720, 840, 960, 1200, and 1440 min after the well is turned on. Plot the drawdown vs. log time. Change the boundary type to a constant head boundary and plot the drawdown vs. log time. Combine the two plots into a single graph (both boundary types - same graphic)

A single pumping well, with a flow rate of 250 gpm, fully penetrates a confined aquifer. The aquifer has a saturated thickness of 110 ft, hydraulic conductivity of 20 ft/d, and storage coefficient of 0.00050. Due to outcropping of the aquifer, a no-flow zone exists 200 ft east of the pumping well and extends as a straight line to both north and south. An observation well is located 100 ft south and 120 ft east of the pumping well. Drawdown in feet at the observation well at time t=1, 5, 10, 20, 30, 40, 60, 80, 100, 120, 240, 480, 600, 720, 840, 960, 1200, and 1440 min after the well is turned on. Plot the drawdown vs. log time. Change the boundary type to a constant head boundary and plot the drawdown vs. log time. Combine the two plots into a single graph (both boundary types - same graphic)

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 6.15P

See similar textbooks

Similar questions

A single pumping well, with a flow rate of 250 gpm, fully penetrates a confined aquifer. The aquifer has a saturated thickness of 110 ft, hydraulic conductivity of 20 ft/d, and storage coefficient of 0.00050. Due to outcropping of the aquifer, a no-flow zone exists 200 ft east of the pumping well and extends as a straight line to both north and south. An observation well is located 100 ft south and 120 ft east of the pumping well. Drawdown in feet at the observation well at time t=1, 5, 10, 20, 30, 40, 60, 80, 100, 120, 240, 480, 600, 720, 840, 960, 1200, and 1440 min after the well is turned on. Change the boundary type to a constant head boundary and plot the drawdown vs. log time.
Calculate the transmissivity of the confined aquifer if the flow is along the strata consist of a 3 layers. The upper layer consist of gravel of 400 cm having hydraulic conductivity of 2.0 cm/sec. The middle layer consists of the fine sand of thickness 300 cm, having hydraulic conductivity of 0.002 cm/sec. The bottom layer consists of coarse sand of thickness 400 cm, having hydraulic conductivity of 0.01 cm/sec.
An unconfined aquifer exists where a buried river channel cut into underlying impermeable bedrock. The figure below shows the orientation and pertinent dimensions. The flow rate at the pumping well is 250 gpm, and its radius of influence is 1000 ft. The hydraulic conductivity of the aquifer is 15 ft/d, and the initial saturated thickness is 120 ft. Find the drawdown at the observation well under equilibrium conditions.
An unconfined aquifer (L1=15m, k 1=1x10-3 cm/s) lies above a confined aquifer(L2=10m, k 2=5x10 -5 cm/s). The two aquifers are separated by a clay layer (Lc=0.5m). A well is placedinto the confined aquifer, and it is observed that the water rises to a height of h = 0.75m above the watersurface in the unconfined aquifer. The water table in the unconfined aquifer is located at the top of theunconfined aquifer. See the schematic below. Determine the following:1) the direction of vertical flow across the clay layer2) determine the hydraulic conductivity of the clay layer, k c, given the water velocity through the claylayer is 5x10-9 cm/s.
In fig 3-5, the aquifer thickness is 10 ft, the hydraulic conductivity of the aquifer is 0.06 m/day, and the river water surface is 7m above the bottom of the aquifer. If it is necessary to maintain a water level in the trench not more than 10 m deep, at what rate must water be pumped out of a 100 m long trench? The distance between the edge of the trench and the river is 300 m. Assume all water comes from the river.
For a typical sand and gravel aquifer, estimate the one-year travel distance for water when the hydraulic gradient is 0.0003 m/m.
A concrete dam is 30 m long from upstream side to downstream end. The dam is situated on a 15-m-thick stratum of soil that has a coefficient of permeability equal to 0.5 m per day. Firm, hard clay and rock underlies thedescribed soil stratum. The base of the dam is installed at a level 2 m below the natural soil surface. Draw the flow net for seepage occurring beneath the dam, and compute the seepage in cubic meters per day per meter ofdam width (perpendicular to the paper), for the condition where the reservoir water against the upstream face of the dam is 18 m above the soil surface and the water level at the downstream end is at the soil surface.
An aquifer has 20m thickness and the rate at which water transfer through a unit width is 0.12 sq.m per second and a void ratio of 0.91. Ground water is flowing through this aquifer with a hydraulic gradient of 0.0065. a. Compute the Seepage velocity.
An uncontined aquifer of(1000)m length having a(k) value of (0.7)m/d is subjected to two sources,the totle head of which are (60)m (at x=0)and (50)m at x=1000m Determine q per unit width of aquifer velocity of flow at x=500m and the heigth of the water table surface at x=500m
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.
An unconfined aquifer is known to be 32 m thick below the water table. A constant discharge of 2 cubic metres per minute is pumped out of the aquifer through a tubewell till the water level in the tubewell becomes steady. Two observation wells at distances of 15 m and 70 m from the tubewell show falls of 3 m and 0.7 m respectively from their static water levels. Find the permeability in mm/s of the aquifer. a.3.28 x 10^-1 b.4.68 x 10^-1 c.2.58 x 10^-1 d.1.18 x 10^-1
A confined aquifer has thickness of 33km and 7km wide. Two observation wells are located 1.2km apart in the direction flow. The head in well one is 97.5m and well two is 89m. i) What is the total daily flow through the aquifer? (Hydraulic conductivity of the aquifer is 1.2m/day) ii) What is the elevation of the potentiometric surface at a point located 0.3 from well one and 0.9 from well two?