In: Civil Engineering

Describe the following: i. Dewatering behind retaining walls ii. Determination of N-value during a standard Penetration Test (SPT) iii. Compaction of deep beds of loose sands

*i)Dewatering behind retaining wall

this method is usually adopted in offshore structure. so avoid water from creating problem for laying foundation or construction of a strucutre, in this case the water need to be diverted or dewatering need to be done. so, retainin walls are constructed in the form of sheet pile walls or other concrete structure to reatain water its behind. Once presence of water is minimized the constrction process becomes easy. water behind retaining wall can further diverted or in case if its a stangant water it can be removed by pumping or other dewatering techniques.

*ii) Determination of N value

standarard penetration test is done to know the resistance of the soil. this method is usually fallowed in soil to determine the resistance and shear strength parameters. the resistance is determined by the N value and later using this N value the bearing capacity of the soil is determined.

Here N value is the the number of blows given by droping the hammer of 65kg to the sampler through the connecting rods upto penetration of 300mm. Initialy sampler is driver 150mm and then for interval of 150mm penetration the N value is recored and its done for total penetration of 300mm. the number blows obtained for last 300mm are considered as the N value. As per indian standard code on SPT is carried upto 300mm penetration or upto 50 blows whichever is earlier. Because excess of blows would lead to daming the sampler.

higher N value represent the harder the soil strata. the SPT s conducted for every 1.5 or 3m interval.

for the obtained values the correction are applied based on the necessity, such corrections are

DILATANCY CORRECTION, OVER BURDEN PRESSURE CORRECTION.

*iii)Compaction of deep beds of loose sand.

comapction is usually done to densify the sand so that settlement after post construction reduced and the structure built are safe.

for densifying the sand most commonly prefered methods are vibrocompaction, stone cloumns,vibroreplacement etc.

Incase of vibrocompaction comapction upto depth of 65-70m has been achieved. in this method a probe is penetrated into sand beds and its made to vibrate, so due to vibration tha sand bed surrounding the probe gets compacted. this process is repeated to the whole area. this method is prefered if the area to be compacted is large and if whole area is used for construction.

In stone columns method the underground columns consist of gravel or crushed rock rock. the method of installtion is same as that use in vibrocomapction.

(b) (i) Describe standard of living and one dimension of
standard of living.
(ii) Describe productivity.
(iii) Explain how productivity related to the country’s standard
of living.
(iv) Identify the factors that determine labour
productivity.

For each of the following difference equations
(i) y[n + 1] + 1.5y[n] = x[n]
(ii) y[n + 1] + 0.8y[n] = x[n]
(iii) y[n + 1] - 0.8y[n] = x[n]
For the difference equations given in Problem 2.16:
(a) Find a closed-form solution for y[n] when x[ n] = 0 for all
n and y[0] 2.
(b) Find a closed-form solution for y[n] when x[n] = u[n] and y[
0] = 0.
(c) Find a closed-form solution for y[n]...

Explain the following concepts:
i.
Mergers, types of mergers and examples
ii.
Acquisitions
Explain the following concepts:
i. What is synergy and
synergistic benefits derived from M&A
ii.
Types of synergies
iii.
How to realize synergies

If X~N (8, σ2),
find:
i. P (8-2σ < X < 8 +3σ)
ii. The value of σ, if P (X ≤ 10) = 0.0778

a. I) describe how microorganisms transform nitrogen during
wastewater treatment ii? give examples of the
microorganism(species, functional groups) involved in nitrogen
transformation reaction

Describe each of the following: (i) Ionic Bonding, (ii)
Electronegativity of an element (iii) MSDS

Consider the following statements: (I) A continuous functions is
always differentiable. (II) The absolute value function is
differentiable everywhere. (III) If f(x) is differentiable
everywhere, with f(−1) < 0, and f(2) > 0, then the equation
f(x) = 0 must have a solution in the open interval (−1, 2). Which
of the following is true?
(a) Only (II) is always true.
(b) Only (I) and (III) are always true.
(c) Only (II) and (III) are always true.
(d) Only (III)...

a) Define the following terms:
i) Calorific Value
ii) Volumetric Percentage with respect to air composition
iii) Gravimetric percentage with respect to air composition
iv) Stoichiometric Ratio
b) In combustion chemistry, state why the usage of excess oxygen
is often desirable.
c) Consider the combustion of pentane. Determine:
i) The stoichiometric air to fuel ratio
ii) The excess air supplied, if 8% CO2 (by vol) is found in the
dry product. ( Take air to be 21% Oxygen,and 79% Nitrogen)

Briefly describe how the following is handled in wind
load analysis:
i) Loading and cladding
ii) Fixity of cladding to a structural member
iii) Design of a structural member carrying cladding.

Give short answers to the following questions: (16)
i. Who is an accountant?
ii. Describe various roles and activities that accountants
perform.
iii. What type of duties does a controller perform?
iv. What is a double entry system? Outline the steps involved in
Double entry system.
v. What is the meaning of ‘Debit’ and ‘Credit’ in accounting?
vi. What is meant by ‘Hybrid basis’ accounting? How the entries are
recorded using this method?
vii. What is the difference between ‘Real...

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