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undrained shear strength of 99kPa. Determine the length of pile needed, if pile

has to carry a load of 370KN with factor of safety of 3 against shear failure. Take
adhesion factor as 0.5.

State the 1.5. guideline for minimum number of boreholes to be taken for a (10)
rectangular area. Determine the minimum number of bore holes needed for a
rectangular plot of size (1) 80mX100m and (11) 300mX80 m?

A 0.3mx0.3m precaste concrete pile, 10m long is driven into a ground. The total (10)
penetration for the last five blows is observed as 12mm. Determine the ultimate

load on pile (Qu) for the following data: weight of hammer=30kN; Height of fall

of hammer=90cm; efficiency of hammer=0.85; sum of the temporary elastic
compressions [in mm] of the dolly, packing, pile and ground=(0.005)Qy. where

Q, is in KN. Efficiency of blow may be assumed as 0.5.

Mention any five objectives of site investigation. Also point out any 5 (10)

information that can be collected during reconnaissance.
Results of load test on a pile [diameter=450mm] are given below: Estimate the (10)

safe load as per LS.

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Choose the correct answer from among the following: (10)

[1] The type of vibration isolation wherein the machine foundation is located
away from the adjoining structures is called :

[A] Passive isolation [B] Damping

[C] Amplification [D] Geometric isolation
[11] Which of the following parameter can be computed, if the values of
coefficient of elastic uniform compression, contact area of footing with soil and
mass of machine, foundation and mass of participating soil mass are known?

[A] Maximum amplitude [B] Damping factor

[C] Magnification factor [1] Natural frequency
[111] Dilatancy correction for N value is applied, only when

[A] soil is coarse sand below water table and N>15

[B] soil is clay below water table and N>15

[C] soil is fine sand below water table and N>15

[D] soil is fine sand above water table and N>15
[iv] Which of the following statement is NOT TRUE?

[A] N value (of SPT) depends upon the relative density of cohesionless soils.

[B] N value is underestimated at shallow depth.

[C] Soil samples collected in wash boring are not representative samples.

[D] Free vibrations occur under the influence of a continuous external force.
[v] As per LS., even if there is no change in soil strata, SPT shall be made at
intervals of :

[A] 1.0m [B] 1.5m [C] 2.0m [D] 3.0m