Rajiv Gandhi Proudyogiki Vishwavidyalaya 2009 B.E Civil Engineering Geotechnical engineering - Question Paper

(i)    The safe depth of the cut, taking a factor of safety of 2 0.

(ii)    The safe depth if S_n 0-217.

7.    (a) Explain the following :    10

(i)    Arching in soil.

(ii)    Earth pressure and its types. Give example.

(b) Derive an expression for active earth pressure when the ground surface is inclined.    10

8.    Write short notes on any four of the following : 5 each

(i)    Formation of soils

(ii)    Quick condition

(iii)    Liquefaction

(iv)    Stability of earth dam

(v)    Reinforced earth retaining walls

CE-704

[ 2 ] ,    CE-704

30 minutes, the corrected hydrometer reading was 12 and the corresponding effective depth 10*5 cm. The specific gravity of the solids was 2-70. Assuming the viscosity and unit weight of water at the temperature of the test as 0-001 N-s/m² and 9*8kN/m³ respectively, determine the weight of solids mixed in suspension, the effective diameter corresponding to the 30 minute reading and the percentage of particles finer than this size.    -,    10

3.    (a) If k_h k₂, &3 are the permeabilities of layers /z₂, h3

thick, what is its equivalent permeability in the horizontal and vertical directions ? Derive the formula used.    10

(b) How coefficient of consolidation is determined with square root of time fitting method ?    10

4.    (a) What is contact pr. ? How does it depend on the type

of structure and type of soil ?    10

(b) A 4 m thick soil stratum has coefficient of permeability of 3 x 10~⁷ m/sec. A separate test gave porosity 40% and bulk unit weight 21 kN/m³ at a moisture content of 30%.

Determine the head at which upward seepage will cause quick sand condition. What is the flow required to maintain critical condition ?    10

5.    (a) Explain the following :    10

(i)    Newmans Influence Chart

(ii)    Pressure Bulb

(b) Discuss in detail Mohrs. Coulombs theory of shear failure of soil.    10

Total'No. of Questions : 8 ] ["Total No. of Printed Pages : 3

roh no.

CE-704 ,

B. E. (Seventh Semester) EXAMIN ATI ON, Dec., 2009 (Civil Engg. Branch)

GEO-TECHNICAL ENGINEERING-I (CE-704)

Time : Three Hours Maximum Marks : 100

i

Minimum Pass Marks : 35

Note : (i) Attempt any five questions.

(ii) Assume any missing/misprint data suitably if required.

1.    (a) Define the following :    10

(i)    Porosity

(ii)    Density Index

(iii)    Plasticity Index

(iv)    Percentage air voids

(v)    Liquidity Index

(b) Discuss the characteristics and construction of Kaolinite, Montmoiillpnite and Illite mineral groups.    10

2.    (a) What is consistency ? Describe different consistency

limits.    10

(b) In a hydrometer analysis, the corrected hydrometer

reading in a 1000 ml. uniform soil suspension at the

start of sedimentation was 28. After a lapse of

P. T. Q