Applied Soil Mechanics M.Tech Model Question Paper : mgu.ac.in
Name of the University : Mahatma Gandhi University
Department : Civil Engineering
Degree : M.Tech
Subject Code/Name : MCEGS 205. 3/Applied Soil Mechanics
Sem : II
Website : mgu.ac.in
Document Type : Model Question Paper
Download Model/Sample Question Paper :
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II : https://www.pdfquestion.in/uploads/mgu.ac.in/5261-2-MCEGS%20205_3%20Applied%20Soil%20Mechanics%20-set%202.doc
Applied Soil Mechanics Question Paper :
M.TECH. Degree Examination :
Model Question Paper – I :
Second Semester :
Branch: Civil Engineering
Related / Similar Question Paper : MGU M.Tech Dynamics of Soil Question Paper
Specialization: Geomechanics and Structures
MCEGS 205. 3 Applied Soil Mechanics (Elective III)
(Regular – 2011 Admission onwards)
Time: 3 Hrs
Max Marks: 100 Marks
Answer all questions :
1. (a) Differentiate Rankine’s and Coulomb’s earth pressure theories. ( 8 marks)
(b) A 6m high vertical wall supports a saturated cohesive backfill (ø = 0) with horizontal surface. For 2m of the backfill, the bulk unit weight and apparent cohesion are 18kN/m3 and 18 kN/m2 respectively and for the next 3m below they are 20kN/m3 and 24 kN/m2.
What is the likely depth of tension cracks behind the wall? If tension cracks develop, what will be the active earth pressure? Draw the pressure distribution diagram and determine the point of application of the resultant pressure. (12 marks)
(c) Explain what is meant by plastic state of equilibrium ( 5 marks)
OR
2. (a) What is active, passive and at rest condition in earth pressure. Give examples for each. What is the effect of wall movement in development of lateral earth pressure. ( 9 marks)
(b) A dry granular level backfill of a 6.3 m high retaining wall weighs 16.2 kN/m3. The active thrust on the wall was 75 kN/m length of the wall. It is intended to increase the height of the wall and at the same time, to keep the force on the wall within permissible limits.
The backfill to a depth of 2.8m from the top is removed and replaced by cinder with ?=8.5kN/m3. If the additional height also to be filled with cinder, estimate the additional height, without changing the initial active thrust. Neglect wall friction and take equal ø value for both soils. ( 16 marks)
3. (a) How is soil selected in reinforced earth applications? What are the popular reinforcing materials? ( 9 marks)
(b) Design a 8m high vertical reinforced earth wall, reinforced with geogrid reinforcement. Uniaxial strength of geogrid is 50 kN/m. The density of wall fill and backfill soil is 16 kN/m and for both angle of internal friction is 30o, C=0.Coefficient of base friction is 0.5.Allowable soil pressure is 250kN/ m2. ( 16 marks)
OR
4. (a) Explain tension crack and critical depth of a vertical cut. ( 6 marks)
(b) A cut 3m wide, 6m deep is proposed in moist sand with =380. Sketch the suitable scheme of sheeting, bracing and also determine the maximum sheet load. Assume density of soil is 18 kN/m3. ( 10 marks)
(c) Explain briefly the principles of design of reinforced earth retaining walls. ( 9 marks)
5. (a) What are the different types of anchorages? ( 8 marks)
(b) An anchored bulkhead retains sand upto a height of 5m.The anchor rod is at a depth of 1m below the top.
The depth of embedment is 2.5m.The angle of shearing resistance of sand is 320.The sand is dry and its dry unit weight is 18 kN/m3.Determine the factor of safety against failure. Use the free earth support method. ( 17 marks)
OR
6. (a) Sketch an anchored bulkhead and mark the pressure distribution for its design, assuming fixed earth support .What are the parameters of soil required for design . ( 10 marks)
(b) An anchored bulk head of total height 12m is constructed in a cohesionless soil. The ground surface on the back of the bulkhead is horizontal and is in level with top of the bulkhead. The dredge line is at 8.4m below the top.
The free water level is at a height of 6m above the dredge line on either side of the bulkhead. Horizontal anchor rods are provided at a depth of 1m below the top. The total unit weight of the soil above the free water level is 17 kN/m3and the submerged unit weight is 11 kN/m3.
The angle of internal friction of the cohesionless soil is 350.Assuming free earth support, determine the factor of safety with respect to the ultimate passive resistance of soil for the depth of penetration. What is the pull in the anchor rod per unit length of the bulkhead? (15marks)
7. (a) An embankment of 12 m height with side slopes 1:1 is to be built of a saturated clay, whose properties are are c = 20kN/ m2, ø = 20, unit weight = 20kN/ m3. The slope is presently completely submerged, but it is anticipated that a sudden drawdown may occur in future and the water table may reach below the toe of the slope. Determine
a) The factor of safety with respect to height corresponding to the submerged and sudden draw down cases, and
b) The factor of safety with respect to shear strength corresponding to the submerged and sudden drawdown cases (25marks)
OR
8. Discuss the method of slope stabilization by the method of ‘drainage’. Explain the various methods.