**B.E. (Civil) ADVANCED FOUNDATION ENGG. (Sem. – II) (2008 Course) (Elective – III)**

Time :3 Hours] [Max. Marks :100

Instructions to the candidates:-

** 1) **Answer 3 questions from Section I and 3 questions from Section II.

** 2) **Answers to the two sections should be written in separate books.

** 3) **Neat diagrams must be drawn wherever necessary.

** 4) **Your answer will be valued as a whole.

** 5) **Use of electronic pocket calculator is allowed.

** 6) **Assume suitable data, if necessary.

SECTION – I

QI) a) Explain ‘significant depth’ and discuss Is code provisions for subsoil exploration for construction of foundations of important structures. [9]

b) Discuss IRC, provisions for explorations, with special reference to number of boring along the centreline of road. [8]

OR

Q2) a) Discuss the different guidelines for construction of important structures, for the depth of exploration. [9]

b) Discuss in brief the different case studies for failures of foundation. [8]

Q3) a) Explain the following : [8]

i) Conventional method for Raft foundation Design.

ii) Soil line method, for Raft foundation Design.

b) A square footing I.2m x I.2m rests at a depth of lm in a saturated clay layer 4m deep. The clay is NC with qu = 40 kN/m^{2}, LL = 30%, Y_{sat} = 17.8 kN/m^{3}, w = 28% 8 g = 2.68. Determine the safe load, which the footing can carry with a FOS = 03 against shear. Also determine the settlement if the footing is loaded with this safe load. Use, Nc = 5.7, Nq = 1 8 Nr = 0. [9]

OR

Q4) a) Discuss the steps for Hansen’s method, for design of shallow foundations subjected to inclined loads. [9]

b) Discuss the various softwares used for geotechnical design 8 explain the use of software ‘Geo-slope’. [8]

Q5) a) Discuss various types of piles based upon the function 8 materials used. [8]

b) How the allowable load for the pile, under test is determined in a cyclic pile load test? Explain with graph. [8]

OR

Q6) a) What do you mean by ‘laterally loaded piles’? How modulus of subgrade reaction 8 relative stiffness factor is determined for LLP? [8]

b) Explain the steps for ‘Reese 8 Matlock’ method. [8]

SECTION – II

Q7) a) How will you determine the load carrying capacity of underseamed pile in the following conditions, [8]

i) Clayey soils.

ii) Sandy soils

b) A clay layer, 5 m thick, is to be consolidated with the help of sanddrains of dia. 30 cm 8 spaced at 2.7 mc/c. Determine the influence of the wells on the Av. degree of consolidation at the time when the degree of consolidation in the clay without sand drains would be equal to 20%. For following conditions. [9]

i) Kr = kz ii) Kr = 5kz.

Assume, square pattern for sand drains for Uz = 20%, Tv = 0.03l. Ur = 0.34, Tr = 0.081, for Tr = 0.407, Ur = 0.87.

OR

Q8) a) Explain double seamed under seam pile construction. [8]

b) Explain the design steps for construction of vertical sand drains. [9]

Explain the design provisions for, [8]

i)

Well curb.

ii) Cutting edge.

iii) Steining thickness.

iv) Bottom plug.

Explain the design of ‘grip length’ 8 ‘normal scour depth’ suggested by ‘Lacey’. Also discuss. method for scour level, according to IRC. [9]

OR

Discuss the various provisions made as per IRC for well foundation design. [8]

Explain the ‘Banerjee 8 Gargopadhyay Analysis’ for design of well foundation. [9]

Differentiate clearly bet^{n} Rockfill cofferdam 8 cellular cofferdam. [8] Explain the steps for design of ‘Anchored sheet pile’ using ‘Free earth support’ method. [8]

OR

Discuss the common types of cofferdam construction. [8]

Compute the embedment depth 8 pull in the anchor rod, for a sheet pile cofferdam of 6m high, retaining soil as a backfill 8 below dredge line, the same soil, with following properties, ^ = 30° C = 0, Y_{sat} = 20 kN/m^{3}, r = 18 kN/m^{3}, Anchor rod = 1 m below the top.

GWT = 3 m above dredge line.Use free earth support method. [8]

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