Chapter 3 caisson

CONTENTS
Introduction
Types of Caisson
Geotechnical Investigation
Caisson Installation Sequence
Advantages Of Caisson
Uses of Caisson
Caisson Disease
Conclusion
2

INTRODUCTION
 Caisson is a water tight structure made of wood, steel, R.C.C
i.e. reinforced cement constructed in connection with
excavation for the foundation of bridges, piers in rivers,
dock structures etc.
 The term caisson has been derived from the French word
‘CAISSEE’, meaning BOX.
 It can be round or rectangle in plan.
 It is commonly used where foundation under water is done.
 It can sunk from surface of either land or water to the
desired depth.
3

DefinitionDefinition::
It’s defined as a structure which
is sunk through ground or water
to exclude water and semi-fluid
materials during the process of
excavation of foundations and
which subsequently becomes an
integral part of the sub-
structure.
4

USES OF CAISSON
 Caissons are more suitable for the deep foundation under water
where the foundation should be extended up to or below the river
bed so as to obtain the proper stability.
 Caissons as type of well foundation is constructed in rivers and lake,
bridges, break water dock structures for the point of view of shore
protection.
 When depth of water in river, lake, or sea etc. are more, then caisson
structure is used.
 It is also used for pump house which are subjected to huge vertical as
well as horizontal forces.
 It is also occasionally used for large and multi-storey building and
other structures.
6

7
 Transferring the load of structure to the hard strata.
 Used for foundation of bridges, piers, abutments in
river or lake.
 Used as impervious core wall of earth dams.
 To provide an access to a deep shaft or tunnel.

Construction Materials:Construction Materials:
Cast-ironCast-iron R.C.C.R.C.C. SteelSteel TimberTimber
•Mostly SuitableMostly Suitable
For Open-wellFor Open-well
Type.Type.
•New Segment OfNew Segment Of
C.I. Are Bolted AsC.I. Are Bolted As
The Caisson Sinks.The Caisson Sinks.
•Unsuitable ForUnsuitable For
PneumaticPneumatic
Caisson.Caisson.
•Risk Of FailureRisk Of Failure
Due To TensionDue To Tension
Developed By TheDeveloped By The
Compressed Air.Compressed Air.
•More CostlierMore Costlier
Than Steel OrThan Steel Or
•MostlyMostly
Suitable ForSuitable For
Caisson Shoes.Caisson Shoes.
•Due To HeavyDue To Heavy
Weight It’sWeight It’s
Difficult ForDifficult For
Handling AndHandling And
Floating TheFloating The
Caisson AtCaisson At
Early Stage OfEarly Stage Of
Construction.Construction.
•Costlier ThanCostlier Than
Steel Caisson.Steel Caisson.
•Most SuitableMost Suitable
For TheFor The
Construction OfConstruction Of
Caisson.Caisson.
•Usually In TheUsually In The
Form Of DoubleForm Of Double
Skin Of SteelSkin Of Steel
Plates.Plates.
•Hollow Space IsHollow Space Is
Filled WithFilled With
CementCement
Concrete.Concrete.
•Mostly Used InMostly Used In
The Early Age OfThe Early Age Of
CaissonCaisson
Construction.Construction.
•Use Of TimberUse Of Timber
Is Very LessIs Very Less
Nowadays.Nowadays.
•Timber Is NowTimber Is Now
Practically NotPractically Not
Adopted Due ToAdopted Due To
Its Bulk And RiskIts Bulk And Risk
Of Fire.Of Fire.
10

Shapes Of Caissons:Shapes Of Caissons:
1. Basic Shapes:1. Basic Shapes:
m
11

2.2. CombinationCombination Of Basic shapes:Of Basic shapes:
12

Types Of Caissons:Types Of Caissons:
Open CaissonsOpen Caissons Pneumatic CaissonsPneumatic Caissons
Well TypeWell Type
SingleSingle
Monoliths (Multiple)Monoliths (Multiple)
CylindersCylinders
13
Box CaissonBox Caisson
(Closed at top and open at bottom)
(Open at top and closed at bottom)
(Open at top and bottom)

Types Of CaissonsTypes Of Caissons
14

Box Caisson:-Box Caisson:-
It is strong water tight vessel
open at top and closed at bottom
and made of timber, steel or RCC.
 It is build on land , cured and
then float or launched to pier site
where it is placed in position.
 Mainly it is used for shallow
depth and for light weight.
The depth of water is about 6 to
8 m. 16

Methods of founding Box CaissonMethods of founding Box Caisson
19

Open caissons or wellsOpen caissons or wells
A well caisson is open at top
as well as bottom.
It’s provided with a cutting
edge at the bottom to facilitate
sinking.
It is made up of timber,
reinforced concrete, steel or
masonry.
It is used for building and
bridge foundation.
It is also known as well
foundations. 20

OPEN OR WELL CAISSON
 Common shapes of caisson
21
The shape of well is generally decided by the requirements of the
superstructure, forces on the well, cost of sinking, base of the pier,
chances of tilting, etc.

Well Components
Cutting edge
Curb
Steining
Bottom plug
Well cap
Top plug
Sand filling 23

WELL COMPONENT FUNCTION
24
 Cutting edge : provides sharp edge to cut the soil below
during sinking operation.
 Curb : during sinking it acts as extension of cutting edge and
provide support the well. It is made of RCC.
 Steining : it is main body of the well. Made of RCC or
masonry with minimum thickness of 45 cm.
 Bottom plug : made of concrete and designed for an
upward load equal to the soil pressure minus self weight of
the bottom plug and sand filling.

WELL COMPONENT FUNCTION
25
 Top plug : It supports the well cap.
 Well cap : It transfers the load from pier to the well.
 Sand filling : It transfers a portion of load from well
cap to the bottom plug.

Laying of Curbs
In dry ground excavate up to 15 cm in river bed and place the cutting
edge at the required position. If the curb is to be laid under
water and depth of water is greater than 5 m, prepare Sand
Island and lay the curb. If depth of water exceeds 5 m built
curb in dry ground and float it to the site.
Procedure for Sinking of Well
foundations

Construction of Well Steining
The steining should be built in short height of 1.5 m initially and 3
m after a 6 m grip length is achieved. The verticality should be
maintained. The aim of the well sinking is to sink the well vertically and
at the correct position.
Precautions – The following precautions should be taken during well
sinking.
•Outer surface should be regular and smooth.
•Radius of the curb should be 2 to 4 cm larger than the radius of the
steining.
•Cutting edge should be of uniform thickness and sharpness.
Sinking Operation
•Up to a depth of 1 m, excavation underwater can be made manually.
When the depth of water exceeds 1 m excavate by Jhams or grabs.

•When well goes on sinking skin friction increases and weight of
well decreased due to buoyancy.
•When the well does not sink, sunk by applying kentledge. If this
operation is not sufficient jet outside the well or grease the outside.
A typical loading on steining by kentledge is shown in Fig 2.
•Go on adding sections of steining (2 to 5 m in length) up to the
required founding strata.

2)2) Multiple Wells(Monoliths):Multiple Wells(Monoliths):
Monoliths are multiple wells
which are sunk together.
Each individual well has got the
separate cutting edge and
dredging in each of the well can
be done separately.
The monoliths are bigger
dimensions, they can not be built
on the site in the water.
29

Construction Of MonolithsConstruction Of Monoliths
 A suitable site is selected on
the upstream side of the river
and dry dock is constructed.
 The dimensions of dry dock
should be kept bigger than
those of the monoliths and it
should be provided with a
door of sufficient width to
take it out.
 The monolith is constructed
up to such height that some
portion of it will remain above
water level when it is sunk. 30

Construction Of MonolithsConstruction Of Monoliths
 The gate of dry dock is opened. The monolith is
then floated and located in its correct position.
 The dredging operation is done in a sequence as
shown in fig. The four dredging units are used
simultaneously and the middle row is touched last.
 After dredging to the required depth, the whole
monolith is gradually sunk uniformly up to the
required level.
 The bottom is provided with a concrete seal, the
wells are filled-with the concrete and cap is
provided at the top to finish up the construction of
monolith.
31

32
• An open cylinder can be conveniently used of the foundation of
bridge piers.
• The cylinder is a light shell which invariably becomes the part of
the permanent structure.
• Cylinders are used as a foundation when depth of water is more
than 12 m or when it becomes essential to go deep to avoid
exposure of foundations due to scouring action of flowing water.
Cylinders:-

34
Disadvantages :-
(1)As the diameter of cylinder is small, it’s load carrying capacity is
less.
(2)There are more chances of lifting of the cylinders.
(3)They require additional for sinking as their self weight is less.
(4)The thickness is less and hence, they are not suitable for the high
bridges.
(5)When water is flowing with high velocity of flow, it is difficult to
sink the cylinders.
Advantages :-
(1)The construction is simple.
(2) The cost is low.
(3)As the diameter of cylinder is small, the obstruction the water
flow is less.
(4)The quantity of excavation is less.
(5)They do not require expensive and complicated lifting devices.

Pneumatic Caissons:Pneumatic Caissons:
 This type of caisson is open at the bottom
and close at the top. Pneumatic caisson is
specially used at the place where it is not
possible to construct the well.
It is suitable for the depth of water more
than 12 m and maximum depth of water up to
35 m.
In the construction of pneumatic caisson,
the compressed air is used to remove water
from the working chamber and the
foundation work Is carried out in dry
condition.
This type of caisson can be made of timber,
concrete or steel. Normally, the tolerable air
pressure under which a man can work is
limited to 0.35 N/mm.
35

37
The construction of the pneumatic caisson is similar to the types
described above, except that, the working chamber and shaft are
made air-tight. In order that the workmen may carry out excavation
work underneath the caisson and the water may not find its way
inside from below, the pressure of the compressed air in the shaft is
kept just higher than that of the water at that depth.
Each caisson has two air locks. Through one air lock workmen go
down for working while through the other excavated material is
taken out.
An air lock essentially consists of a steel chamber having two air-
tight doors. One door of this chamber serves as an entry for men
and material from outside into the steel chamber and the other
door leads to the air shaft.
Construction procedure of pneumatic caissons

38
When a workman enters the airlock from outside, the pressure
inside the airlock is the same as that of outside atmosphere.
Thereafter the outside door is closed and the pressure inside the
airlock is raised slowly. When the pressure inside the airlock
becomes equal to the pressure in the caisson, the door of the
airlock which leads to the air shaft is opened and the workman
goes down the air-shaft with the help of a ladder installed therein.
Exactly reverse procedure is followed when the workman comes
out of the caisson. Air-shaft provides means of access for the
worker from airlock down to the working chamber.

40
Advantages of Pneumatic Caissons- The advantages of pneumatic
caissons are that all work can be done in dry and there is control
over work. The foundation is prepared better and plumbness of
caissons is easier to control. The concrete placed in dry condition
will have good and reliable quality. The obstruction from boulders
and logs can readily be removed and excavation by blasting may
be done if necessary.
Disadvantages of Pneumatic Caissons- Pneumatic caissons have
high cost of construction. They cannot be sunk to depths greater
than 35 m because the higher pressure below this depth cannot
be resisted by human body.

Pneumatic caisson sickness
1) When workers working under compressed air inside the
working chamber, they suffer certain type of disease when
they return to the atmospheric pressure. This disease is
known as “caisson sickness” or “caisson disease”.
 The main symptoms of the diseases are:
1) Dizziness
2) Double vision
3) Headache
4) Trouble to speaking
41

(Precautions)
1) No person should work for more than one shift in a day.
2) Shift should not exceed 12 hours.
3) Temperature of the working chamber should be maintain 25 degree
centigrade.
4) The main locks should be well ventilated.
5) Persons with strong heart, low blood pressure and good circulation
should be employed on the work.
6) Use of alcoholic drinks should be prohibited.
7) Medical facility or chamber should be provided nearer to the work.
42

(Precautions)
8) The workers should take enough meal before the shift starts.
9) All the passages, shafts etc. of the caisson should be well
ventilated and properly lighted.
10) The worker use man locks for entry, interval and exit.
43

Loads On Caissons:Loads On Caissons:
Dead Loads: Dead Loads: The Weight Of The Superstructure And The The Weight Of The Superstructure And The
Self Weight Of The Well Foundation Constitute The Dead Self Weight Of The Well Foundation Constitute The Dead
Loads.Loads.
•Live LoadsLive Loads
•Longitudinal ForceLongitudinal Force
•Earth PressureEarth Pressure
•Centrifugal ForcesCentrifugal Forces
•Temperature StressesTemperature Stresses
44

Loads On Caissons:Loads On Caissons:
Sinking Loads: These Loads Include The Force To Which A Caisson Is Subjected
During Sinking Operations.
These Chief Sinking Forces Are As Follows :
45
Sinking Loads: These Chief Sinking Forces Are As Follows :
Buoyancy Forces: When The Well Is Founded On Course Sand, Full Buoyancy
Equal To The Weight Of The Displaced Volume Of Water Is Considered. For Semi
Previous Foundation, Appropriate Reduction May Be Made Based On The Location
Of Water Table.
Friction: This Force Will Depend On The Sink Friction Of The Type Of Soil And It
Should Be Limited To Such An Extent That The Caisson Sinks Of Its Own Weight
When Earth Is Removed From Within The Caisson.
Internal Air Pressure: This Forces To Be Taken Into Account In Case Of
Pneumatic Caissons Only.
Hogging And Sagging Stresses: These Forces Are Developed In Early Stages
Of Sinking Large Rectangular Caissons. The Excavations Within The Caisson Should
Be Carried Out Carefully To Minimize The Intensity Of These Stresses.

Floating Of Caissons:Floating Of Caissons:
Sometimes, Sometimes, A Part Of The Bottom Portion Of The Caisson Including A Part Of The Bottom Portion Of The Caisson Including
Cutting Edge Is Constructed On The Shore And It Is Then Floated And Cutting Edge Is Constructed On The Shore And It Is Then Floated And
Placed In Position, This Process Is Called Placed In Position, This Process Is Called Floating Of CaissonFloating Of Caisson..
46

Methods Of Floating Of Caissons:Methods Of Floating Of Caissons:
1) 1) Construction Of Dry RockConstruction Of Dry Rock
A Dry Dock Is Constructed On The A Dry Dock Is Constructed On The
Upstream Side Of The Flow. The Upstream Side Of The Flow. The
Required Portion Of The Caisson Is Required Portion Of The Caisson Is
Built In The Dry Dock.Built In The Dry Dock.
The Dry Dock Is Then Flooded To The Dry Dock Is Then Flooded To
Float Out The Prepared Portion Of The Float Out The Prepared Portion Of The
Caisson. The Caisson Should Be Caisson. The Caisson Should Be
Properly Anchored When It Is Floating Properly Anchored When It Is Floating
And Loading.And Loading.
This Is Some Time Is Done By This Is Some Time Is Done By
Providing R.C.C. Pre-cast Block Near Providing R.C.C. Pre-cast Block Near
The Final Position Of The Caisson. The The Final Position Of The Caisson. The
Blocks Are Dumped Into The River And Blocks Are Dumped Into The River And
Wrapped By Cables Or Wire By Divers.Wrapped By Cables Or Wire By Divers. 47

2) 2) Floating From BankFloating From Bank
The Caisson Can Be The Caisson Can Be
Floating From The River Floating From The River
Bank. In Case Of River Bank. In Case Of River
Bank With Steep Slope , Bank With Steep Slope ,
Girders Projection Inside Girders Projection Inside
The River Are Supported The River Are Supported
On Piles.On Piles.
The Caisson Is Prepared The Caisson Is Prepared
On The Shore, Rolled To On The Shore, Rolled To
Other End And Then Other End And Then
Lowered Into The River By Lowered Into The River By
Suitable. In Case Of River Suitable. In Case Of River
Bank With A Gentle Slope, Bank With A Gentle Slope,
The Slipway Is Prepared.The Slipway Is Prepared. 48

2) 2) Floating From BankFloating From Bank
The Caisson Is Built On The Caisson Is Built On
The Shore And Rolled On The Shore And Rolled On
Slipway. When It Reaches Slipway. When It Reaches
The Other End Of Slipway, The Other End Of Slipway,
It Starts Floating In It Starts Floating In
Water.Water.
The Caisson In Both The The Caisson In Both The
Case Is Then Suitably Case Is Then Suitably
Carried And Placed In Carried And Placed In
Final Position.Final Position.
49

3) 3) Turning Of CaissonsTurning Of Caissons
This Method Is Adopted This Method Is Adopted
When When Depth Of Water Is Depth Of Water Is
High.High. The Caisson Is The Caisson Is
Launched Upside Down Launched Upside Down I.E.I.E.
Cutting Edge Is Upward And Cutting Edge Is Upward And
The Top Is At Bottom.The Top Is At Bottom.
The Potion On Side Is Kept The Potion On Side Is Kept
Side Higher Than The Side Higher Than The
Remaining One. The Sand Is Remaining One. The Sand Is
Used To Maintain Symmetry Used To Maintain Symmetry
During Launching. During Launching.
The Stone Ballast And Water Are Then Added To Cause Tilting Of The Stone Ballast And Water Are Then Added To Cause Tilting Of
Caisson. When Complete Turning Occurs, The Caisson Starts Floating Caisson. When Complete Turning Occurs, The Caisson Starts Floating
In The Water And Stone Ballast Falls Out Of The Caisson.In The Water And Stone Ballast Falls Out Of The Caisson.
50

Cutting Edges Of Caissons:Cutting Edges Of Caissons:
The The lowermost portion of a caisson is provided with a cutting edge lowermost portion of a caisson is provided with a cutting edge
so as to facilitate the sinking of caisson. so as to facilitate the sinking of caisson.
Properties Of A Cutting Edge:Properties Of A Cutting Edge:
It should be strong enough to resist the stresses likely to develop It should be strong enough to resist the stresses likely to develop
during the sinking operations of the caisson.during the sinking operations of the caisson.
It should be capable of preventing sudden sinking of the caisson It should be capable of preventing sudden sinking of the caisson
when a soft stratum is met with.when a soft stratum is met with.
In case of pneumatic caissons, it should be air tight i.e. capable of In case of pneumatic caissons, it should be air tight i.e. capable of
preventing escape of air.preventing escape of air.
The edge should be wall protected by the steel point to avoid any The edge should be wall protected by the steel point to avoid any
damage to the edge.damage to the edge.
The outer edge should be vertical.The outer edge should be vertical.
The inside angle of inclination depends on the type of the soil. For The inside angle of inclination depends on the type of the soil. For
hard soil ,it should be small.hard soil ,it should be small.
The reinforcing bars should be provided between the cutting edge The reinforcing bars should be provided between the cutting edge
and the wall to have proper bond to avoid reparation between them. and the wall to have proper bond to avoid reparation between them. 51

Types Of Cutting Edges:Types Of Cutting Edges:
1)1)Cutting Edges With Sharp Ends:Cutting Edges With Sharp Ends:
This type of cutting edge has a sharp edge. It is used for the open This type of cutting edge has a sharp edge. It is used for the open
steel cylinders.steel cylinders.
52

Types Of Cutting Edges:Types Of Cutting Edges:
2)2)Cutting Edges With Blunt Ends:Cutting Edges With Blunt Ends:
It is suitable when a caisson is to be sunk through a rock and land It is suitable when a caisson is to be sunk through a rock and land
surface.surface.
53

Sinking Of Caissons:Sinking Of Caissons:
The Various Methods Adopted To Facilitate The Sinking Of Caissons Are:The Various Methods Adopted To Facilitate The Sinking Of Caissons Are:
A) Air And Water Jets:A) Air And Water Jets:
In This Method, Jets Are Provided Near The Cutting Edge Level To In This Method, Jets Are Provided Near The Cutting Edge Level To
Reduce The Skin Friction.Reduce The Skin Friction.
The Jet May Be Embodied In The Body Of The Caissons Or They The Jet May Be Embodied In The Body Of The Caissons Or They
May Be Operated Independently By Drivers Or Other Workmen.May Be Operated Independently By Drivers Or Other Workmen.
Air Or Water Is Forced Through The Jets Which Ultimately Air Or Water Is Forced Through The Jets Which Ultimately
Facilitates The Sinking Of Caisson.Facilitates The Sinking Of Caisson.
54

B) Blasting:B) Blasting:
In This Method, Explosives Are Used To Remove Any ObstructionIn This Method, Explosives Are Used To Remove Any Obstruction
Such As Rock, Boulder, Etc. And There By To Facilitate Sinking OfSuch As Rock, Boulder, Etc. And There By To Facilitate Sinking Of
Caisson.Caisson.
The Blasting Also Helps In Reducing Skin Friction Of Hard Soils.The Blasting Also Helps In Reducing Skin Friction Of Hard Soils.
The Cutting Edge Is Cleared And Suitable Charge Of Explosive IsThe Cutting Edge Is Cleared And Suitable Charge Of Explosive Is
Provided At A Depth Of About One To Two Metres Below The CurbProvided At A Depth Of About One To Two Metres Below The Curb
Level.Level.
The Usual Explosive Used In Blasting Gelatine.The Usual Explosive Used In Blasting Gelatine.
It Is Powerful Under Water And Convenient To Use. The QuantityIt Is Powerful Under Water And Convenient To Use. The Quantity
To Be Used Per Blast Is About 0.10 To 0.50kg.To Be Used Per Blast Is About 0.10 To 0.50kg.
It Is Necessary To Take Extreme Care To See That The Cutting EdgeIt Is Necessary To Take Extreme Care To See That The Cutting Edge
Of Caisson Is Not Damaged The Blasting Operations.Of Caisson Is Not Damaged The Blasting Operations.
55

C) Loading:C) Loading:
While Sinking Of Caisson, When A HardWhile Sinking Of Caisson, When A Hard
Surface Is Met With, The Weight Of TheSurface Is Met With, The Weight Of The
Steining Proves To Be Insufficient For TheSteining Proves To Be Insufficient For The
Further Sinking Of The Well.Further Sinking Of The Well.
In Such Cases, Loading Of The Well IsIn Such Cases, Loading Of The Well Is
Carried Out. The Old Rails Are Put Up AtCarried Out. The Old Rails Are Put Up At
The Top. These Rails Provide Good AndThe Top. These Rails Provide Good And
Smooth Large Bearing Surface On TheSmooth Large Bearing Surface On The
Masonry And Can Take Up Heavy Loads.Masonry And Can Take Up Heavy Loads.
Wooden Or Steel Joists Are Then Placed On There Rails And 50mmWooden Or Steel Joists Are Then Placed On There Rails And 50mm
To 60mm Thick Planks Are Placed Over The Joists To Complete TheTo 60mm Thick Planks Are Placed Over The Joists To Complete The
Loading Platform.Loading Platform.
On This Platform, Bags Filled With Same Are Placed To ImpartOn This Platform, Bags Filled With Same Are Placed To Impart
Additional Weight To The Well. This Facilitates Sinking Of The Well.Additional Weight To The Well. This Facilitates Sinking Of The Well.56

57
Tilting and Shifting of cassionsTilting and Shifting of cassions
When a well sinks more on one side than the other, then it is known o
have tilted. The tilting is mainly due to unequal dredging and non
uniform bearing power of soil.
Regulations Of Excavation
Eccentric loading
Water JettingWater Jetting
Pulling The WellPulling The Well
Strutting The WellStrutting The Well
Pushing The Well With JacksPushing The Well With Jacks

Tilting and Shifting of cassionsTilting and Shifting of cassions
Regulations Of Excavation: The
Higher Side Is Grabbed More Be Regulating
The Dredging. In The Initial Stages This May
Be All Right. Otherwise, The Well May Be
Dewatered If Possible, And Open Excavation
May Be Carried Out On The Higher Side.
Eccentric loading: Eccentric Placing Of
The Kentledge May Be Reported To Provide
Greater Sinking Effort On The Higher Side. A
Platform With Greater Projection On The
Higher Side May Be Constructed And Used
For This Purpose. As The Depth Of Sinking
Increases, Heavier Kentledge With Greater
Eccentric it Would Be Required To Rectify
Tilt. 58

Water Jetting: If Water Jets Are Applied
On The Outer Face Of The Well On The
Higher Side, The Friction Is Reduced On That
Side, And The Tilt May Get Rectified.
Pulling The Well: In The Early Stages Of
Sinking, Pulling The Well To The Higher Side
By Placing One Or More Steel Ropes Round
The Well, With Vertical Sleepers Packed In
Between To Distribute Pressure Over Larger
Areas Of Well Steining, Is Effective.
59

Strutting The Well: The Well Is
Strutted On Its Tilted Side With Suitable
Logs Of Wood To Prevent Further Tilt. The
Well Steining Is Provided With Sleepers To
Distribute The Load From The Strut. The
Other End Of The Logs Rest Against A Firm
Base Having Driven Piles.
Pushing The Well With Jacks: Tilt
Can Be Rectified By Pushing The Well By
Suitably Arranging Mechanical Or
Hydraulic Jacks. 60

Picture Gallery:Picture Gallery:
61

Chapter 3 caisson

More Related Content

What's hot (20)

Similar to Chapter 3 caisson (20)

More from KHUSHBU SHAH (20)

Recently uploaded (20)

Chapter 3 caisson