15. A confined aquifer underlies an unconfined aquifer as shown in the figure. Given the following: D₁-59 m, D₂=41 m, H₁-45 m, H₂=33 m, K₁=35 m/day, K₂=27 m/day, L= 2 km. D₁ H₂ H₂ K₁ K₂ D₂ a. Calculate the equivalent coefficient of permeability in horizontal direction. b. Calculate the hydraulic gradient.

15. A confined aquifer underlies an unconfined aquifer as shown in the figure. Given the following: D₁-59 m, D₂=41 m, H₁-45 m, H₂=33 m, K₁=35 m/day, K₂=27 m/day, L= 2 km. D₁ H₂ H₂ K₁ K₂ D₂ a. Calculate the equivalent coefficient of permeability in horizontal direction. b. Calculate the hydraulic gradient.

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

Given: velocity of flow = 0.0375 m/s coefficient =0.05 m/s porosity p =48% slope S = 3/4 Given the coefficient =0.05 m/s and porosity p =48%, find the transmissibility (T) in m/s per unit m, if the aquifer width is 1.2 m.
Given: r1 = 30 m h = 13.6 m r2 = 10 m h1 = 17.6 m H = 20 m h2 = 16.3 m t = 15 m d = 0.6 m ø Q = 13 L/s a.)Find the permeability of the aquifer in m/s. b.)Compute for the transmissivity of the impermeable layer in m2/s.
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
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
From the figure shows an unconfined non homogeneous aquifer between two water bodies at depth of 50 m and 45 m. respectively. Compute the average coefficient of permeability of the aquifer and the rate of flow.
L = 370 mm A = 145 cm^2 h = 340 mm Water collected in 3 min Q = 580 cm^3 Void ratio of sand e= 0.66 Determine the Hydraulic conductivity and seepage velocity.
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.
Refer to Problem 8.4. Using the flow net drawn, calculate the hydraulic uplift force at the base of the hydraulic structure per meter length (measured along the axis of the structure).8.24 For the hydraulic structure shown in Figure 8.24, draw a flow net for flow through the permeable layer and calculate the seepage loss in m3/day/m.
Given the coefficient k =0.05 m/s and porosity p = 48%, find thetransmissibility (T) in m/s per unit m, if the aquifer width is 1.2 m.Formula: - It is the flow rate per day thru a unit areaunder a unit hydraulic gradient For an aquifer with thickness, Band width, X:T = K*B and Ag = BXThus: Q = (T*X*S)
From the figure shown, H1 = 0.60, H2 = 0.90 m. and h = 0.45 m. The sad has a saturated unit weight of 18.65 kN/m3 . Hydraulic conductivity of sand K = 0.12 cm/sec. If the cross sectional area of tank = 0.46 m2 , determine the following: 1. Total stress and Effective stress at C. 2. Pore water pressure at C. 3. Rate of upward seepage of water in liters/sec.
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 meters per minute is pumped out of the aquifer through a tube well till the water level in the tube well becomes steady. Two observation wells at distances of 15 m and 70 m from the tube well show falls of 3 m and 0.7 m respectively from their static water levels. Find the permeability of the aquifer (mm/s).