Unit 5 - Week4:Soil Permeability

24/07/2018 Geology and Soil Mechanics - - Unit 5 - Week4:Soil Permeability

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Course outline Assignment 4 The due date for submitting this assignment has passed. Due on 2016-02-26, 23:55 IST. How to access the portal Submitted assignment

Week Tick True or False against the following statements 1:Engineering geology of soils and Index 1) Soil permeability coefficient is directly proportional to void ratio of soil medium. 1 point properties of soils True False Week 2:Classification No, the answer is incorrect. of soils, soil Score: 0 structure and Accepted Answers: clay mineralogy False

Week 3:Soil 2) Soil permeability is mostly dependent on Darcy’s Law. 1 point Compaction True Week4:Soil False Permeability No, the answer is incorrect. Module 16 - Score: 0 Permeability Accepted Answers: Module 17 - True Permeability 3) Turbulent flow can occur when water flows through soil pores. 1 point Module 18 - Permeability True Module 19 - False Permeability & Seepage No, the answer is incorrect.

Module 20 - Score: 0 Seepage Accepted Answers:

Quiz : True Assignment 4 4) Soil permeability coefficient is directly related to viscosity coefficient of the medium 1 point Solution For Assignment 4 True False Week5:Seepage and In-situ No, the answer is incorrect. stresses Score: 0 Accepted Answers: Week6:In situ stresses and False Consolidation 5) Falling head test is for sandy type of soil 1 point https://onlinecourses.nptel.ac.in/noc16_ce01/unit?unit=32&assessment=34 1/6 24/07/2018 Geology and Soil Mechanics - - Unit 5 - Week4:Soil Permeability

Week True 7:Consolidation False

No, the answer is incorrect. Week 8:Consolidation Score: 0 and Shear Accepted Answers: Strength False

Week 9:Shear 6) The horizontal and vertical coefficients of permeability for a soil are almost same. 1 point Strength of soils True Week 10:Shear False Strength of soils No, the answer is incorrect. Week 11 : Score: 0 Tutorial Lessons Accepted Answers: and Earth pressure False theories - Part 1 7) A compacted soil is going to have lower permeability compared to a non compacted soil. 1 point

Week 12 : True Tutorial Lessons and Earth False Pressure No, the answer is incorrect. theories - Part 2 Score: 0 Tutorials -2 Accepted Answers: True

8) Only falling head tests can be conducted in field. 1 point

True False

No, the answer is incorrect. Score: 0 Accepted Answers: False

9) The velocity of water through soil is same as the discharge velocity. 1 point

True False

No, the answer is incorrect. Score: 0 Accepted Answers: False

10)Permeability of soils with lower degree of saturation is more compared to fully saturated 1 point soils.

True False

No, the answer is incorrect. Score: 0 Accepted Answers: False

Read the following paragraphs and answer the following questions

A) A soil sample is prepared in a hollow cylindrical mould of diameter 50 mm and height 100 mm having a weight of 245 gm. The soil mixture was prepared by mixing 50 https://onlinecourses.nptel.ac.in/noc16_ce01/unit?unit=32&assessment=34 2/6 24/07/2018 Geology and Soil Mechanics - - Unit 5 - Week4:Soil Permeability gm of water with 350 gm of dry soil mass and was compacted in 5 layers in the cylindrical mould. The specific gravity of the soil solids was found out to be 2.65. The soil mixture filled up to the brim after compaction. The sample was placed vertically and a flow of water at a constant rate was applied from the top of the sample at a height of 150 mm from the base of the sample. Afterwards, a high pressure was applied to compact the sample from both sides. A decrease in height of 10 mm for the sample from bottom side only was observed.

11What) is the permeability of soil before high pressure application if 500 cc of 1 point water gets collected in 30 minutes from the base of the sample?

1E-04 cm/sec 2.34 E-04 cm/sec 9.43E-03 cm/sec 5 E-02 cm/sec

No, the answer is incorrect. Score: 0 Accepted Answers: 9.43E-03 cm/sec

12What) is the void ratio of the sample before high pressure application? 1 point

0.65 0.49 0.78 0.30

No, the answer is incorrect. Score: 0 Accepted Answers: 0.49

13What) is the permeability of soil after high pressure application if 300 cc of 1 point water gets collected in 30 minutes from the base of the sample?

9.03E-03 cm/sec 5.46E-03 cm/sec 3.45E-05 cm/sec 5.09E-03 cm/sec

No, the answer is incorrect. Score: 0 Accepted Answers: 5.46E-03 cm/sec

14What) is the void ratio of the sample after high pressure application? 1 point

0.34 0.59 0.62 0.17 https://onlinecourses.nptel.ac.in/noc16_ce01/unit?unit=32&assessment=34 3/6 24/07/2018 Geology and Soil Mechanics - - Unit 5 - Week4:Soil Permeability No, the answer is incorrect. Score: 0 Accepted Answers: 0.34

15Assuming) the relative density in field is 40% corresponding to the maximum 1 point and minimum void ratio before and after application of pressure, what is the permeability of the soil in field?

3.42 E-03 cm/sec 2.78 E-03 cm/sec 4.45 E-03 cm/sec Can’t say from the given data

No, the answer is incorrect. Score: 0 Accepted Answers: Can’t say from the given data

B) A falling head test is to be conducted in a soil sample of mould 150 mm in diameter and 300 mm in height. The stand pipe discharges an amount of 0.5 cc for a height of 2 mm. The height of water in the stand pipe at time t=0, t=10, t=20, t=30, t=40, t=50, t=80, t=110 seconds are 90, 86, 83, 81, 80, 79.5, 79.3 and 79.1 mm respectively. The base of the standpipe is connected to the top of the sample. The outlet is attached to the base of the sample.

16What) is the permeability of the sample? 1 point

1.09E-04 cm/sec 2.20E-04 cm/sec 4.22E-06 cm/sec 7.46E-06 cm/sec

No, the answer is incorrect. Score: 0 Accepted Answers: 7.46E-06 cm/sec

17Suddenly) instead of water motor oil starts to flow through the sample due to 1 point some malfunction in the system. What should be the permeability of the oil given that the viscosity of water and oil are 8.94E-04 and 0.065 Pa.s respectively?

1.50E-06 cm/sec 3.03E-06 cm/sec 1.03E-07 cm/sec Can’t say from the given data

No, the answer is incorrect. Score: 0 https://onlinecourses.nptel.ac.in/noc16_ce01/unit?unit=32&assessment=34 4/6 24/07/2018 Geology and Soil Mechanics - - Unit 5 - Week4:Soil Permeability Accepted Answers: 1.03E-07 cm/sec

18Assuming) the same test to be conducted in a field for the same soil having 1 point observation wells of height 30 cm and 45 cm respectively and at a distance of 50 and 70 cm from the well, what should be the expected discharge?

0.078 cc/sec 1.144 cc/sec 2. 31 cc/sec 0.091 cc/sec

No, the answer is incorrect. Score: 0 Accepted Answers: 0.078 cc/sec

19If) in field 20 number of layers of equal thickness (10 cm) are present in a 1 point stratified soil deposit with the bottom layer of the above mentioned soil, and the vertical permeability for each layer increases by 5 times of the layer below it, what is the equivalent vertical hydraulic conductivity of the deposit?

Can’t say from the given data 2.73E-03 cm/sec 1.87E-04 cm/sec 1.28E-04 cm/sec

No, the answer is incorrect. Score: 0 Accepted Answers: 1.28E-04 cm/sec

20If) in field 20 number of layers of equal thickness (5 cm) are present in a 1 point stratified soil deposit with the bottom layer of the above mentioned soil, and the horizontal permeability for each layer increases by 2 times of the layer below it, what is the equivalent horizontal hydraulic conductivity of the deposit? Assume the horizontal permeability of the given soil to be 5 times the vertical permeability

Can’t say from the given data 4.85 cm/sec 1.96 cm/sec 28.57 cm/sec

No, the answer is incorrect. Score: 0 Accepted Answers: 4.85 cm/sec

https://onlinecourses.nptel.ac.in/noc16_ce01/unit?unit=32&assessment=34 5/6 24/07/2018 Geology and Soil Mechanics - - Unit 5 - Week4:Soil Permeability

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