The soil profile below a lake with water level at elevation = 0 m and lake bottom at elevation = -10 m is shown in the figure, where k is the permeability coefficient. A piezometer (stand pipe) installed in the sand layer shows a reading of +10 m elevation. Assume that the piezometric head is uniform in the sand layer. The quantity of water (in m³/s) flowing into the lake from the sand layer through the silt layer per unit area of the lake bed is: +10 Elevation (m) E-10 -30 -40 Stand pipe Lake Silt (k = 10-6 m/s) ▼ Sand parek(under artesian pressure) Rock Lake bottom

The soil profile below a lake with water level at elevation = 0 m and lake bottom at elevation = -10 m is shown in the figure, where k is the permeability coefficient. A piezometer (stand pipe) installed in the sand layer shows a reading of +10 m elevation. Assume that the piezometric head is uniform in the sand layer. The quantity of water (in m³/s) flowing into the lake from the sand layer through the silt layer per unit area of the lake bed is: +10 Elevation (m) E-10 -30 -40 Stand pipe Lake Silt (k = 10-6 m/s) ▼ Sand parek(under artesian pressure) Rock Lake bottom

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 7.14P

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1. (30 pts) The soil profile shown below consists of 10 meters of sandy silt overlying gravel. The pore water pressure at the top surface of the silty sand is zero and can be assumed to remain zero. a) Calculate the level to which water would rise in a piezometer tube inserted into the top of the gravel if the silty sand is just stable? Use submerged unit weights and seepage forces to arrive at your answer (do not calculate total stresses and pore water pressures). Express your answer as an elevation, e.g. "Elev. 130". (Note: Elevations are in meters) (10 pts) b) Using the piezometric elevation calculated in part (a), calculate the pore water pressure at the bottom of the silty sand if the silty sand is just stable (10 pts). c) Calculate the total stress at the base of the silty sand and show that it is equal to the pore water pressure calculated in part (b) (10 pts) Elev. 120 m. Elev. 110 m. Sandy Silt (saturated) Void ratio, e = 0.68 G = 2.65 Gravel
For a falling-head permeability test, the following values are given: Length of specimen = 200 mm %3D Area of soil specimen = 1000 mm^2 %3D Area of standpipe = 40 mm^2 Head difference at time t = 0 = 500 mm Head difference at timt t 180 seconds = 350 mm %D %3D Determine the hydraulic conductivity of the soil in x10 4 cm sec
HYDRAULIC CONDUCTIVITY PROBLEM 1: The results of a constant head permeability test for a fine sand and sample having a diameter of 150 mm and a length of 150 mm are as follows: Constant head difference = 40 cm Time of collection of water = 83 sec Weight of water collected = 392 g Find the hydraulic conductivity a. 0.094 cm/sec b. 0.01 cm/sec C. c. 0.005 cm/sec d. 0.86 cm/sec
The data from a falling-head test on a silty clay are: Cross sectional area of soil = 1000 mm^2 Length of soil sample = 200 mm Area of stand pipe = 40 mm^2 Head difference at time t = 0 is 500 mm Head difference at time t = 3 min is 300 mm a) Determine the hydraulic conductivity of the soil in cm/sec. b) What is the head difference at time t = 100 sec in mm
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Question 40 The results of a constant head permeability test for a fine sand are as follows: Diameter of the sample = 25 cm Length of sample = 80 cm Constant head difference = 77 cm Time of collection = 388 secs Weight of water collected = 340 grams Find the seepage velocity in cm/min. if the void ratio is 0.49. Round off to four decimal places.
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