Engineering is the professional art of applying science to the optimum conversion of the resources of nature to benefit man. The internship at Cochin Shipyard,DMRC and Vytilla helped in bridging the gap between theory and practice and provided practical,field based and real world experience.

1. INTERNSHIP

2. INTRODUCTION
• Engineering is the professional art of applying science to the optimum conversion of
the resources of nature to benefit man.
• The internship at Cochin Shipyard,DMRC and Vytilla helped in bridging the gap
between theory and practice and provided practical,field based and real world
experience.

3. C O C H I N
S H I P YA R D
L I M I T E D
( C S L )

4. COCHIN SHIPYARD
• Started on Dec 3 and ended on Dec 15
• On the first day of our internship there,an introduction video was showed which
highlighted the need and importance of safety at construction site.
• During these days we also got the opportunity to visit the construction site of INS
Vikrant(R11).It is the first aircraft carrier built in India.
• The remaining days were scheduled to visit the Infra Projects Department.There we
had an opportunity to visit the two main ongoing projects under the department.
 Dry Dock
ISRF

5. NEW DRY DOCK PROJECT
• At present CSL has two dry dock has two dry dock.One predominantly used
for ship building,of size 255m X 43m X 9m and capacity 1,10,000 DWT and
other for ship repair of size 270m X 45m X 12mand capacity 1,25,000 DWT
• This third dry dock of northern end of existing CSL yard with size of 310m X
75/60m X 13m will be the largest of dry dock in CSL to enhance capability
to take up construction maritime equipments such as rigs to be repaired
or constructed at the wider part of the dock.
• The new dry dock will be equipped with one gantry crane of capacity
600T,two LLTT cranes of capacity 75T and other allied facilities .

6. • The estimated cost of total dry dock project is Rs.1799 crores.
• The new dry dock project is in line with the “Make in INDIA ” programme of
govt. of India, which promotes creation of additional ship building and
repair facilities.
• Employer:CSL
• Engineer: Royal Haskoning DHV
• Contractor: L&T
• The duration of the work is 36 months and the tentative data of
completionis 31st May 2021.
• The main works taking place are
Piling
PVD
Cofferdam

7. PILING
• Construction Procedure
Bored pile with temporary casing using polymer system consists of three
main stages,which are :surveying,boring,reinforcing and casting.
Surveying works
 For the fixation of piles, standard reference points are used.Atleast two
reference points is required for coordinate system and atleast one
reference point is for standard level.
 Using precise survey instrument like total station,coordinates of pile is
fixed on ground with respect to standard coordinates.
 Before starting piling work coordinates are verified again to minimise
location error.

8. Reinforcement Cages
 Steel reinforcement cages will be prepared according to approved drawings and
materials.Bundle bars consisting of three steel bars are used for reinforcing.
 A lap length of 5d is adopted.Both welding and coupling is used for lapping the bars
.For providing coupler,bars undergoes cutting,forging and threading.Reducing couplers
are used to join bars of different diameter.Vizag steel of length 24m are used in the site.
Boring
 A temporary short steel casing of depth 9m is installed for guiding in boring of pile.It
also supports top loose soil and prevents collapse due to machine movement and
vibration.The diameter of casing is 2m.
 Piles were drilled using hydraulic hydraulic rotating rig.Borehole is filled with polymeric
slurry which is prepared and stored in special tanks.This slurry will maintain stability by
providing a thin film coatingin the borehole wall.
 Properties of polymer mix
Viscosity: >55sec
pH value: 9-12
Sand content : <3%
Density: 1-1.06 g/cc

9. Placing of reinforcement
 When founding level has been reached ,steel reinforcing cage will be
lowered into the borehole.Concrete spacers are used ensure that it is
located centrally.
Placing of Concrete
 The principle used here is that when the concrete of densith 2400kg/cm3
is poured into the borehole,the polymer with lower density gets displaced
from the bottom.After concreting the temporary casing is pulled out.
• The total number of piles is 5200.Out of which 1210piles were
completed.Around700 are anchor piles and remaining bearing piles.
• Bearing piles are provided to take up compressive load.
• Sheet piles are provided throughout,these are anchored into pile cap of
anchor piles using rods.These take up tension.

10. PVD
• The entire area is divided into six zones namely A,B,C,D,E &F and a granular
layer of 500mm is laid.
• PVD is installed with 1m c/c spacing in triangular pattern.A non-woven
geotextile is laid above that.as per design 4.5m thick surcharge was placed
over geotextile.
• The entire setup facilitate vertical as well as radial consolidation.The water
drained is collected in the drains at the sides..
• The zones A,B and C are placed in single stage(26 weeks).For the zones D &E
surcharge were placed in 3 stages (32 weeks)
• 4 vibrating wire piezometers were installed at each zones with one at the
center.6 settlement gauges were installed in each zone.
• PVDs are installed to reduce active pressure on the dock walls.

11. PVD Installation

12. ISRF
• Cochin Port Trust has a small dry dock and marine workshop at the
southern end of Willington Island,facing Mattancherry channel.It is for
reparing and maintenance of small vessels.
• ISRF is a brownfield project since ship repair activities are presently
progressing in dry dock and marine workshop.As a part of modernization
CSL is presently in the process of setting up a shiplift and transfer system of
6000T lifting capacity.
• The project cost is estimated to be 970 crores .Repairs of around 85 vessels
per are expected once the facility becomes fully operational.

13. • Location : Willington Island
• Engineer : Marine work - Inros-lackner (German based)
• : Land work - Tata Consultancy Engineers Ltd.
• Contractor : Simplex Constructions
• Commencement : 17 November 2017
• Duration : 24 months
• Estimated cost : 970 crore Rupees

14. GEOTECHNICAL INVESTIGATION
• A geotechnical investigation was conducted at the marine boreholes.It was
proposed take 14 boreholes.
• Soil investigation was entrusted to M/S Engineer’s Diagnostic Centre(Pvt)
Limited,Cochin.This pact deals with ground investigation works to find out
an ideal foundation for the proposed project.
• The works included site reconnaissance, drilling and sampling of boreholes,
conducting field and lab tests and the report preparation.
• The primary purpose of these activities was to collect subsurface
information at site for design of foundations for the proposed work.

15. FIELD EXPLORATION AND TESTING
• Boring was done in accordance with the provisions of IS 1892-1979,using
rotary calyx rig technique which is mechanically operated.While drilling
through the top soil layers sodium bentonite slurry was circulated in order
to prevent the sides from collapsing.
• SPT were taken at various depths using standard split spoon sampler as
per IS 2131-1981.The number of blows required to penetrate first 15cm is
for seating and is not considered for assessing strength characteristics.
• Results are recorded in borelog.Soil sample is collected in plastic bags for
visual inspection and classification of strata.

16. • Samples obtained from samplers are tested for :strength and properties
to classify strata.
• Moisture content(IS 2720 Part II-1973)
Water content is an important index for establishing relation between
soil properties and behaviour. Consistency of fine grained soil
depends upon its water content. It is used in expressing phase
relations.
• Grain Size Distribution(IS 2720 Part IV-1985)
Both sieve analysis and hydrometer analysis were conducted on
different samples and findings are tabulated.Particle diameter span
many orders of magnitude for natural sediments so base to log scale
was used to represent grain size information for sediment
distribution.
• Specific Gravity(IS 2720 Part III 1980)
It was determined using pycnometer or density bottle.

17. • The total area of site is 42 acres out of which 14 acres is covered by water.
Marine and land piling works are now progressing. Total piles are 1688 in
number. In this there are 722 marine piles and 966 land piles. Following
super structures are also under construction:
1. Security cabin
2. Main electrical substation
3. Paint store
4. Mains receiving station
5. Compressor shed
6. Toilet block
7. Acetylene station

18. • In addition to this a 1.3 km long compound wall is under construction.
• Plum concrete is used in the compound wall and foundation of
superstructure.
• Basically, plum means large sized aggregates (boulders) that are rubbles of
180-210mm size.
• These are adopted if large sized top aggregates are not available. Strength
will be same as rubble masonry.
• Here alternate layers are made with PCC and rubbles of mentioned size. Out
of total 100%, 60% will be concrete and rest 40% aggregate.
• Concrete of this type is called plum concrete. Here M15 grade concrete is
used as PCC.

19. PILING
• For both land and marine piling casing used are permanent and they are
made at the site by rolling metallic sheets of 8mm thickness and welding
them together.
• Casing is provided only up to 20m depth. Instead of using
polymer,bentonite slurry is used which helps in flushing the bore hole
and also supports the unlined soil with the formation of thin film.
• Piles of 1m, 1.2m and 1.5m diameters are used at different areas and
depth of pile in both marine and land areas vary from 46 to 61m. For
M30 and M40 grade concrete, an admixture is used.
• It is Auramix 400 by Forsoc. Auramix 400 is an advanced low viscosity,
high performance super plasticizer, based on polycarboxylic technology.

20. • The properties are:
Appearance: Light yellow coloured liquid
 pH: Minimum 6.0
 Chloride content: Nil to IS: 456
 Alkali content: Typically, less than 1.5g Na2O equivalent/litre of
admixture
 Normal dosage range: Between 0.5 to 3.0 litres/100kg of cementitious
mate

21. D E L H I M E T R O
R A I L
C O R P O R AT I O N
( D M R C )

22. • The Delhi Metro Rail Corporation (DMRC) is a state-owned company that
operates the Delhi Metro in the National Capital Region of India.
• DMRC undertakes the planning and implementation of metro rail, mono rail
and high-speed rail projects in India.
• In Kerala the DMRC undertakes the construction of Kochi Metro.
• Geometrical design norms are based on international practices adopted for
similar metro systems
• assumption maximum permissible speed on the section = 80 km.
• Tracks will be carried on U-shaped elevated decking supported by single
circular piers generally spaced at 28 m centres
• Track centre on the elevated section will be 3.7 m on portions of tracks which
are straight or having curvature up to radius of 150 m.
• Track centre will be increased to 4 m on curves with radius sharper than 150 m.

24. PILE CONSTRUCTION
• Deep foundation
• Piles of diameter 1 & 1.2m are used in this project.
• The maxim m height of the pile is 42 m.
• M40 grade concrete is used for the construction of piles.

25. BORED CAST IN SITU PILE
• Digging a hole in the ground by rotary method with the use of temporary casing
• Total Station is used to set out pile position
• Drive steel casing to a minimum a depth of 1 m below the ground level to take
lateral loads and movements at site
• Soil samples from each intermediate soil strata at different depths are taken for
soil tests.
• reinforcement cage is lowered into to the borehole vertically, without disturbing
the sides of the hole.

26. • cover blocks are provided all around the cage
• Stirrups, stiffeners and laps are then welded to prevent
breakage.
• tremie method of piling is adopted -to bring the
concrete through a pipe to the interior of the concrete
being poured, thus preventing contact with the
surrounding water.
• Concrete is continuously fed to the tremie pipe-
through a hopper and the pipe is lifted as the concrete
level rises.
• Concrete is added continuously until the pouring is
completed.

27. PILE CAP CONSTRUCTION:
Pile Cap: A reinforced concrete slab or block which interconnects a group of
piles and acts as a medium to transmit the load from wall or column to the
Piles
• 4 pile cap and 6 pile cap reinforcement works were in progress
• designed like a footing on soil but instead of uniform reaction from the
soil, the reactions in this case are concentrated either point loads or
distributed.

28. UNDER REAMED
PILE
CONSTRUCTION
SITE

29. DETAILS ABOUT THE PROJECT
• The site was at Vytilla and the proposed work was the construction of a 3 storey
building. The pile depth was 12 m at the site. A sum total of 63 piles are required
in this project and among these 11 piles were completed before our site visit.
• The pile diameter adopted was 50 cm and the bulb diameter was 60 cm. The
concrete used for the pile was M50 and the reinforcement of 12 mm diameter
along with 8 mm diameter rings were provided.
• The piles were either single under reamed or double under reamed, which
depended on the sand content and the depth at which clay layer occurred.
• Auger boring is done on the site up to the depth of 12 m and bulb is given at a
distance of 50 cm from the bottom of the pile (Bottom bulb). If double under
reamed pile was installed the next bulb was given near clay layer.

30. UNDER REAMED PILE
• Under reamed piles are bored cast-in-situ concrete piles having one or more
number of bulbs formed by enlarging the pile stem.
• These piles are best suited in soils where considerable ground movements
occur due to seasonal variations, filled up grounds or in soft soil strata.
• Provision of under reamed bulbs has the advantage of increasing the bearing
and uplift capacities.
• It also provides better anchorage at greater depths.

31. • These piles are efficiently used in machine foundations, over bridges, electrical
transmission tower foundation sand water tanks.
• Indian Standard IS 2911 (Part III) - 1980 covers the design and construction of
under reamed piles having one or more bulbs.
• According to the code the diameter of under reamed bulbs may vary from 2 to 3
times the stem diameter depending upon the feasibility of construction and design
requirements.
• The code suggests a spacing of 1.25 to 1.5 times the bulb diameter for the bulbs. An
angle of 450 with horizontal is recommended for all under reamed bulbs.
• The code also gives mathematical expressions for calculating the bearing and uplift
capacities.

32. CONSTRUCTION OF UNDER REAMED
PILE
• Under reamed piles are bored cast-in-situ concrete piles having one or more
number of bulbs formed by enlarging the pile stem.
• These piles are best suited in soils where considerable ground movements occur
due to seasonal variations, filled up grounds or in soft soil strata.
• Provision of under reamed bulbs has the advantage of increasing the bearing
and uplift capacities.
• It also provides better anchorage at greater depths.

33. • The process consists of various stages involving: boring by augers, under reaming by under-reamer,
placing reinforcement cage in position, concreting of pile, concreting of pile caps, plinth beams and
curtain walls.
Stages in Construction of Under Reamed Pile

34. • The equipment required for construction of pile are
Auger boring guide
Spiral auger with extension rods
Under reamer with soil bucket
Concreting funnel
• The use of boring guide is necessary to keep bore holes vertical and also in
position.
• After setting the guide assembly in position, the spiral auger is introduced into the
circular collar of the by opening out two sets flaps of the guide assembly.
• The auger is pressed down and rotated manually until the spirals are half full of
earth. The auger is then taken out and earth removed.
• The boring process is repeated till the required depth is reached.

35. • Under reaming or enlarging the stem of bore hole at required depth is achieved by
means of the under reamer consisting of a set of two collapsible blades assembly
fixed around the central shaft and a detachable bucket for receiving cut soil.
• The equipment is attached to extension rods and lowered down the hole which has
been bored to the required depth, until the bucket rests at the bottom of the bore
hole.
• The guide flaps are then closed. The tool is pressed down constantly and rotated
slowly.
• The cutting blades of the tool widen out and start cutting sides of hole. The loose
earth is collected in a bucket at the bottom.
• When bucket is full, the assembly is pulled out and bucket is emptied. The depth of
the of bore hole is checked each time before insertion of under reamer so that any
loose earth spilled from the bucket is removed.

36. Under Reamer

37. THANK YOU