Hall Ticket No Question Paper Code: ACE006
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
B.Tech IV Semester End Examinations (Supplementary) July, 2018
Regulation: IARE R16
GEOTECHNICAL ENGINEERING
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. What are the corrections to be applied in hydrometer analysis? Explain.
A saturated sample of undisturbed clay has a volume of 19.2cm3 and weighs 32.5g. After oven
drying, the weight reduces to 20.2g. Determine the following
(i)Water content Specific gravity Void ratio Saturated density of clay sample.
2. Explain in brief about Montmorillonite and Illite mineral.
What are the different types of soil structures? Explain them with neat sketch.
UNIT II
3. Write short notes on quick sand condition.
Determine the average coefficient of permeability in the horizontal and vertical directions for
a deposit consisting of three layer of thickness 5m, 1m and 2.5m and having the coefficient of
permeability of 3 mm/sec, 3 mm/sec and 4 mm/sec respectively. Assume
the layers are isotropic.
4. A sample in a variable head permeameter is 8 cm in diameter and 10 cm high.The permeability
of the sample is estimated to be 10 × 10-4 cm/s. If it is desired that the head in the stand pipe
should fall from 24 cm to 12 cm in 3 min., determine the size of the stand pipe which should be
used.
What are the various parameters that affect the permeability of soil in the field? Critically
discuss.
UNIT III
5. Describe the assumptions to be taken in Bousinesq's theory and write the equation of stress for
a concentrated point load.
The maximum dry density of a sample by the light compaction test is 1.78 gm/cc at an optimum
water content of 15%. Find the air voids and degree of saturation. Specific gravity G=2.67.
What would be the corresponding value of dry density on the zero air void line at OMC?
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6. What are various effects of compaction on properties of soil? Explain them in detail.
Explain the following:
i. Isobar
ii. Geostatic stress
iii. Assumptions used in Westergard's theory
iv. Formula for vertical stress under circular area
UNIT IV
7. Discuss the assumptions in Terzaghi's theory of consolidation.
A clay layer 4m thick is subjected to a pressure of 55kN/m2. If a layer has double drainage
and undergoes 50% consolidation in one year, determine the coefficient of consolidation. Take
Tv=0.196, if the coefficient of permeability is 0.020m/yr. Determine the settlement in one year
and rate of flow of water per unit area in one year?
8. Define and explain initial consolidation, primary and secondary consolidation.
The laboratory consolidation data for an undisturbed clay sample are as follows. e1=1.00,
e2= 0.80, 2=465kN/m2. Determine the void ratio for a pressure of 600kN/m2.

UNIT V
9. Draw the neat sketch of triaxial compression test apparatus. Explain its components and working
principle.
A sample of dry cohesionless soil was tested in a triaxial machine. If the angle of shearing
resistance was 360 and confining pressure 100kN/m2, determine the deviator stress at which the
sample failed.
10. What type of field tests is necessary for determining the shear strength parameters of sensitive
clays? Derive the relationships that are useful for analyzing the observations of this test.
A shear vane of 7.5cm diameter and 11cm length was used to measure the shear strength of the
soft clay. If a torque of 600 N-m was required to shear the soil, Calculate the shear strength.