09A50104 Geotechnical Engineering-I B.Tech Question Paper : sphoorthyengg.com
Name of the College : Sphoorthy Engineering College
University : JNTUH
Department : CIVIL ENGINEERING
Subject Code/Name : 09A50104/GEOTECHNICAL ENGINEERING-I
Degree : B.Tech
Year/Sem : III/I
Website : sphoorthyengg.com
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/sphoorthyengg.com/4855-09A50104%20-%20GEOTECHNICAL%20ENGINEERING-I.pdf
Geotechnical Engineering-I Question Paper :
B. Tech III Year I Semester Examinations, December-2011
(CIVIL ENGINEERING)
Time: 3 hours
Related : Sphoorthy Engineering College 09A50106 Waste Management B.Tech Question Paper : www.pdfquestion.in/4854.html
Max. Marks: 75
Answer any five questions :
All questions carry equal marks :
1.a) Derive from fundamentals: es = Gw, where ‘s’ represents degree of saturation, ‘e’ represents void ratio, ‘w’ represents water content, and ‘G’ represents grain specific gravity.
b) The dry unit weight of a sand sample in the loosest state is 13.34 kN/m3 and in the densest state, it is 21.19 kN/m3. Determine the density index of this sand when it has a porosity of 33%. Assume the grain specific gravity as 2.68. [7+8]
2. a) Define and distinguish the following in terms of their use in soil engineering:
i) Consistency Index and Liquidity Index
ii) Flow Index and Toughness Index
b) A soil sample has a liquid limit of 20% and plastic limit of 12%. The following data are also available from sieve analysis
Classify the soil approximately according to Indian Standard Classification. [7+8]
3. a) Define and distinguish the following:
i) adsorbed & absorbed water ii) Discharge velocity & Seepage velocity.
b) A bed of sand consists of three horizontal layers of equal thickness. The magnitude of the coefficient of permeability for both the upper and lower layer is 7 x 10-5 mm/s and for the middle layer is 3 x 10-3 mm/s. What is the ratio of the average permeability of the bed in the horizontal direction to that in the vertical direction? [7+8]
4. a) Demonstrate the quick sand condition with a neat sketch and derive the expression for critical hydraulic gradient.
b) An earth dam of 80 m wide is built on an impervious foundation with a horizontal filter at the base near the toe. The permeability of the soil in the horizontal and vertical directions is 8 x 10-3 mm/s and 2 x 10-3 mm/s respectively.
The full reservoir level is 40 m above the filter. A flow net constructed for the transformed section of the dam, consists of four flow channels and 12 head drops. Estimate the seepage loss for the entire length of dam. [7+8] 1
5. a) Discuss the construction of Newmark’s influence chart for vertical stress estimation.
b) A light house is constructed on a circular ring type foundation. The intensity of loading on the foundation is 200 kPa.
The outer diameter of the ring foundation is 16m and the internal diameter is 12m. Determine the vertical pressure directly below the centre of the foundation at depths of 4m and 6m. [7+8]
6. a) Write brief notes on ‘compaction’ and ‘consolidation’ of soils and differentiate the two.
b) Discuss how quality control of compacted earth mass is ensured in the in-situ. [7+8]
7. a) Define the following:
i) Under consolidated soil
ii) Normally consolidated soil and
iii) Over consolidated soil. Also discuss the reasons for over consolidation of soil.
b) There is a bed of compressible clay of 4 m thickness with previous sand on top and impervious rock at the bottom.
Consolidation test conducted on an undisturbed specimen of clay of 20 mm thick obtained from the same deposit showed that 90% settlement has reached in 4 hours. Estimate the time in years for the building founded over this deposit to reach 90% of its final settlement. [7+8]
8. a) What are the drained and undrained shear tests? Under what conditions should the drained shear strength or the undrained shear strength parameters are used? Explain.
b) The following results were obtained at failure in series of triaxial compression tests, on specimens of clay. Determine the values of shear strength parameters c and f either by drawing the Mohr circles or analytically. [7+8] Confining Pressure (s3), kPa