construction methods and equipments
TRANSCRIPT
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CONSTRUCTION METHODS AND EQUIPMENTS
UNIT – 1
1. Define excavation. What are the methods are used in excavations?
Excavation work generally means work involving the removal of soil
or rock from a site to form an open face, hole or cavity using tools,
machinery or explosives. Excavation has a number of important applications
including exploration, environmental restoration, mining and construction.
The two methods of excavations are,
Mass excavation
Structural excavation
2. What are the problems normally developed during deep excavations?
To prevent the collapsing of sides of the trenches
To prevent water oozing or coming out from the sides and bottom of
the trenches
3. What are the remedial measures to avoid the problems in deep
excavation?
Providing shoring for the trenches
Dewatering of the trenches
4. Define foundation.
Foundation is a part of the structure which is present below the ground
level. It supports the weight of the structure and the load carried by it. The
type of the foundation depends upon the bearing capacity of the soil.
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5. What are the types of foundation?
Shallow foundation
Spread foundation
o Strip footing
Simple footing
Stepped footing
o Column footing
Isolated column footing
Combined column footing
Raft foundation
Grillage foundation
Deep foundation
Pile foundation
Pier foundation
Well foundation
6. Define pier foundation.
A pier foundation consists of a cylindrical column of large diameter to
support transfer large super imposed loads to the firm strata below.
Generally pier foundation is shallower in depth than the pile foundation. It
has two types.
Masonry pier
Concrete pier
7. What are the types of caisson?
Open caisson
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Box caisson
Pneumatic caisson
8. What is caisson?
Caissons are structural boxes or chambers. These are sunk in place
through the ground or water by excavating below the bottom of the unit
which enables the caisson to reach the final depth.
These structures have a large cross – sectional area and hence provide
high bearing capacity, which is much larger than what may be offered by a
cluster of piles.
9. What are the materials used for construction of caissons?
Cast iron
Reinforced Cement Concrete
Steel
Timber
10. Give the uses of caissons.
To reach the hard bearing structure for transferring the load coming
on support for bridge piers and building columns
To serve as an impervious core wall of earth dams When placed
adjacent to each other
To provide an access to a deep shaft or a tunnel
11. What are the operations involved in open caisson method of
foundation?
Constructing or fabricating the caisson and preparing site to receive it
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Placing the caisson over the site of the pier
Excavating the soil from the interior of the caisson and advancing the
caisson so than its cutting edge is at or below the bottom of the
excavation
Continuing this process until the foundation in the hard stratum is
reached
Sealing the bottom of the caisson to exclude water and soil
12. Define box caisson.
It is open at the top and closed at the bottom and is made of timber,
reinforced concrete or steel. This type of caisson is used where bearing
stratum is available at shallow depth.
13. Define open caisson.
Open caisson is a box opened both at top and bottom. It is made up of
timber, concrete or steel. The open caisson is called well. Well foundation is
the most common type of deep foundation used for bridges in India.
14. Define pneumatic caisson.
Pneumatic caissons has its lower end designed as a working chamber
in which compressed air is forced to prevent the entry of water and thus
excavation can be done in dry conditions.
15. Define basement.
Basement or cellar is the lower storey of a building constructed or
partly below the ground surface.
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16. Define basement construction.
Construction of basement is difficult for it must be carried out below
deep ground in adverse condition such as existence of ground water,
muddiness or limited working space. Besides, works are needed to be done
amidst layers of props, struts, waling and shores, which cannot be removed
until the permanent works are completed and capable of carrying the final
loads.
17. What are the methods of basement constructions?
Use of lattice beams
Use of ground anchors
Construct floor slab as support (top down method)
Cast the centre basement slab to support struts
In – situ reinforced concrete and tradition formwork system
18. Define braced wall. What are the types of braced wall?
A braced wall is a structural system composed of braced panels (also
known as shear panels) to counter the effects of lateral load acting on a
structure. Wind and seismic loads are the most common loads that braced
walls are designed to carry.
TYPES:
Single diagonal
Double diagonal
Chevron bracing
Storey height knee bracing (eccentricity braced frames)
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19. Define soil nailing. What are the types of soil nail wall?
Soil nailing is an earth retention technique using grouted tension-
resisting steel elements (nails) that can be design for permanent or temporary
support. The walls are generally constructed from the top down. Typically, 3
to 6 feet of soil is excavated from the top of the planned excavation.
TYPES:
Grouted soil nailing
Driven nails
Self-drilling soil nail
Jet grouted soil nail
Launched soil nail
20. What are the applications of soil nail wall?
Roadway cuts
Road widening under existing bridge abutments
Tunnel portals
Repair and reconstruction of existing retaining structures
Hybrid soil nail systems
Shored Mechanically Stabilized Earth (SMSE) walls
21. What are the advantages of soil nail wall?
Creates less noise and traffic obstructions
Less impact on nearby properties
Allow excellent working space in front of the excavation face
Can be used for strengthening of either natural slope, natural or man –
made cut slopes
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Grouting only once is required, saving time and labor
The technique is flexible, easily modified
22. What are the disadvantages of soil nail wall?
Nail encroachment to retained ground rendering unusable
underground space
Generally larger lateral soil strain during removal lateral support and
ground surface cracking may appear
Tendency of high ground loss due to drilling technique, particularly at
course grained soil
Less suitable for course grained soil and soft clayey soil, which have
short self-support time, and soils prone to creeping
Suitable only for excavation above groundwater
23. Define sheet pile wall. What are the types of sheet pile wall?
A sheet pile wall consists of a series of sheet piles driven side by side
into the ground, thus forming a continuous vertical wall for the purpose of
retaining an earth bank. They are commonly used for water front structures,
temporary construction and light weight construction where sub – soil is
poor for supporting a retaining wall. A sheet pile wall may be of three types.
They are,
Cantilever sheet piling
Anchored sheet piling
Braced sheeting
24. Give the different types of sheet piles based on materials.
Concrete sheet pile
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Timber sheet pile
Steel sheet pile
25. Write the functions of sheet piles.
To enclose a site or part thereof to prevent the escape of loose subsoil,
such as sand, and to safeguard against settlement.
To retain the sides of the trenches and general excavation.
To protect river banks.
To protect the foundations from scouring actions of nearby river,
stream etc. To construct costal defense works
26. What are the uses of sheet pile?
To protect river banks
To retain the sides of foundation trenches
To resist flow of underground or loose soil or of both
To resist bending abrasion or other stresses which may arise in use
27. Define dewatering.
Dewatering means removal of excess water from the saturated soil. It
is used where the water table is high or in the case of deep excavations the
foundation trenches for buildings and other structures, are filled with seeped
water.
28. What are the methods of ground water control?
Pumping from open sumps
Pumping from well points
Pumping from bored wells
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29. What are the methods of dewatering?
Ditches
Well point system
Shallow well system
Deep well system
Vaccum method
Electro osmosis method
30. Write the essential features of a pump to be used for dewatering.
The pump should be portable so that it can be easily moved as and
when required
The pump should be capable of handling water mixed with impurities
such as sand, earth, etc.
The pump should be of strong make
The performance of pump should be reliable
31. What are the methods of water proofing?
Cementitious water proofing
Liquid water proofing membrane
Bituminous membrane
Bituminous coating
Polyurethane liquid membrane
32. Define trenching.
A trench is defined as a narrow excavation (in relation to its length)
made below the surface of the ground. In general, the depth of a trench is
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greater than its width, but the width of a trench (measured at the bottom) is
not greater than 15 feet (4.6 m).
33. What are the types of trenching?
Single slot trenching
One side stepped trenching
Two side stepped trenching
Multi stepped trenching
One side sloped trenching
Two side sloped trenching
34. What are the advantages of using trenchers?
It is faster and cheaper method of trenching
It digs only as much as is necessary
A 10cm pipe can be installed in a 15cm wide slot cut by a trencher
It is a continuous process and is not like that of backhoe excavator
(i.e.) dug lift – dump
35. On what basis you will select the equipment for the construction?
Volume of the material to be removed
Size of the machine used
Depth of excavation
Height to be lifted
Soil type
Duration of period
Rented or purchased
Production cost
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Spares availability
Skilled operation
36. What are the types of earth moving equipment for construction?
Production equipment
Equipment used for digging and moving
Service equipment
Dozers and motor girders
37. List out the material handling devices.
These are the lifting and lowering devices (vertical motion).
Block and tackle
Winches
Hoists
Elevators
Pillar crane
Overhead crane
38. List out the transportation devices (horizontal motion).
Wheel borrows and hand truck
Narrow gauge mine rail road
Tractors and trailers
Skids
Pipe line
39. List out the applications of motor grader.
Land clearance
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Snow clearance
Material mixing
Hard surface cutting
Ditch filling or digging
Bank cutting and reshaping
40. What are the devices used for combination of lifting, lowering and
transportation operations?
Spiral chute
Lift track
Crane truck
Forklift truck
Conveyors of various types
41. What is a tractor? Mention its types.
Tractor is earthmoving equipment which converts engine energy into
tractive energy. The two types of tractors are,
Crawler or tract type
Wheel or pneumatic type
42. What are the factors to be considered while selecting a tractor?
Size of the dozer for a given job
The type of work expected from the tractor dozer
Example: bulldozing, ripping, land clearing, pulling a scraper
The type and condition of hauled road
Gradient of the haul road
Distance to be moved
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Type of work expected to be taken from the equipment after the
present job is completed
43. What are the advantages of crawler excavator?
More tractive effort, hence can also operate on loose or muddy soil
In absence of tyres, can easily operate in rocky conditions, as there is
no danger for the damage of the tyres
Where maintenance of haul roads is difficult, it can be easily travel,
especially in rough terrains
Crawler tractors are more compact and powerful and hence can handle
difficult jobs as well
44. What are the advantages of wheeled tractors?
Can travel at higher speeds during the operation and also from one job
to another
Can travel long distance at its own power, whereas crawler mounted
needs trailers
When work is spread over long area, there are found to be producing
more output
Easy in operation. Operation feels less fatigue.
45. What are the uses of excavators?
Digging of trenches, holes and foundations
Material handling
Brush cutting with hydraulic attachments
Forestry work
Demolition
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General grading/landscaping
Heavy lift, e.g. lifting and placing of pipes
Mining, especially, but not only open-pit mining
River dredging
Driving piles, in conjunction with a Pile Driver
46. List out the types of excavators.
Compact excavator
Crawler excavator
Wheeled excavator
Backhoe loader
Dragline excavator
Bucket wheel excavator
Long reach excavator
Power shovel
Suction excavator
47. What are the main uses of a bulldozer?
Clearance of shrubs and small trees
Clearance of trees by using raised mould blade as a pusher arm
Acting as a towing tractor
Acting as a pusher to scraper machines
48. What are the applications of bulldozer?
Land clearing
Stripping
Side hill cuts
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Ditching
Spreading
Dozing rocks and frozen ground
Maintaining haul roads
Clearing the floors of borrow and quarry pits
49. Differentiate between crawler and pneumatic types of wheels.
CRAWLER TYPE WHEEL PNEUMATIC TYPE WHEEL
The crawler moves on an endless
chain
It moves on pneumatic tyres
They are slow speed They are faster in speed
They are used for uneven & rough
ground
They operate best on smooth roads
They have a speed of about 12kmph They have a speed of about 50kmph
50. What is motor grader?
Motor graders are used for leveling and smoothening of the
earthwork, spreading and leveling the base courses in the construction of
roads and airfield. It can be used for land reclamation, snow clearance,
gravel road repairing, mixing of stabilizing materials such as tar, asphalt,
cement and lime, maintaining quarry roads, etc.
51. What is a scraper?
Scrapers are the device to scrap the ground and load it simultaneously,
transport it over the required distance, dump at desired place and then spread
the dumped material over the required area in required thickness level, and
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return to the pit for the next cycle. The scrapers are of three types. They
are,
Towed type
Self-propelled or motorized
Self-loading or elevating scraper
52. What are the three types of scraper?
Crawler drawn scraper
Two axle scraper
Three axle scraper
53. What are the advantages of elevating scraper?
Better loading ability in loose free flowing materials
Good finishing ability
Can be operated independently
Pusher tractor dozer is not required
Smooth and complete unloading of bowl by reversing the elevator
rotation
Pulverizing and mixing action by the elevator places material in
uniform and homogeneous state for compaction.
54. Write short note on skimmers.
These excavators are rigged using a universal power unit for surface
stripping and shallow excavation work upto 300mm deep where a high
degree of accuracy is required. They usually require attachment haulage
vehicles to remove the spoil and need to be transported between sites on a
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low loader. Because of their limitations and the availability of alternatives
machines, they are rarely used today.
55. What are the factors governed the output of a dragline?
Output or the performance of the dragline depends on the following
factors,
Nature of soil
Depth of cut
Angle of swing
Capacity of hauling units, if employed
Mechanical condition of the dragline
Efficiency and skill of the operator
56. Write short notes on draglines.
Cranes are machines designed to move materials vertically (rise by
rope pulley operation) or horizontally. The range of cranes available is very
wide, from gear wheel to a complex tower crane. Therefore, choice must be
based on:
The loads to be lifted
Height of lifting
Horizontal distance to be covered
Time period of lifting operations
Utilization factors and
Degree of mobility required
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57. What is the power shovel?
It is used to excavate the earth of all classed and load it into wagons.
They are mounted on crawler tracks. It consists of a mountain, cab, boon,
dipper, strip, hoist line.
58. What is a clamshell?
Clamshell is a machine having most of the characteristics of dragline
and crane in common. Digging is done like a dragline and once the bucket
is filled, it works like a crane. It is very useful for accurate spot dumping of
material in a confined space in a vertical plane. It can be used for handling
of loose or soft and medium hard materials only.
59. What are the methods of underwater concreting?
Tremie method
Pump method
Toggle bags
Bags work
60. What are the types of temporary earth retaining structures?
Braced wall
Sheet pile wall
Soil nail wall
61. Define blasting.
Blasting is the process of discharging of an explosive to loosen the
rock.
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62. What are the parameters to be examined while blasting for quarrying?
While blasting for quarrying or excavation, the following parameters
are to be examined.
Spacing of the drill holes
Diameter of the drill holes
Depth of the drill holes
Burden of the rock at the toe
Burden of the rock at the crest
Degree of fragmentation desired and
Strength of the explosives to be used
63. Define dredging.
It is the process of excavating from river bed, lake or sea for the
purpose of deepening them. It is an important operation in navigation
canals, harbors, dams etc.
64. What are the types of dredgers?
Dipper dredger
Ladder dredger
Suction dredger
65. What is line system?
This system is employed when excavation area is long. The header is
laid out along the sides of the excavation, and the pumping is continuously
in progress in one length as further points are jetted ahead of the pumped
down section and pulled up from the completed and back filled lengths and
repeated till entire length is completed. For narrow excavation, like trenches,
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header is laid only on one laid, while for wide excavations, the header are
required to be placed on both sides of the area.
66. What is ring system?
When excavation is done in area of appreciable width, line system is
inadequate. The ring system is used in such condition and the header main
surrounds the excavations completely. This system is used for rectangular
excavations such as for piers or basements.
67. Where is grout anchors used in constructions?
In most cases, however anchorages may be embedded below ground
level, with backstays connecting them to adjacent towers, or they may
constitute the end abutments of the end spans. In addition to stability sliding,
the anchorage structure must also be checked for stability against tilting and
overturning.
68. Define texture. What are their classifications?
Texture is defined as the grain size of the rock. It is classified into 5
categories such as,
Porous rock
Loose grained rock
Granitoid rock
Fine grained rock
Dense rock
69. List out the construction equipment.
Bull dozers
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Graders
Skimmers
Scrapers
Loaders
Face shovels
Backhoe
Draglines
70. Mention the various operations involved in grading.
Grading
Spreading
Finishing and leveling
Ditch digging
Cutting
Bank cutting
Earthen road maintenance
Earthen road construction
Repairing gravel road
UNIT – 2
1. Define pile foundation.
A pile is a slender column made of wood, concrete or steel. A pile is
either driven into the soil or formed in situ by excavating a hole and then
filling it with concrete. A group of piles are driven to the required depth and
are capped with R.C.C. slab, over which super structure is built. The pile
transfer the load to soil by friction or by direct bearing, in the latter case,
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piles being taken up to hard strata. This type of foundations is used when top
soil is not capable of taking the load of the structure even at 3–4 m depth.
2. Write the situations under which pile foundation is recommended.
When spread footing, raft and grillage foundations are uneconomical
When heavy concentrated loads are to be transmitted by the
foundation
Where there is scouring in the soil near the foundations
Where the soil is made up and of a compressible nature
3. Give the different types of piling.
Rotary board technique
Continuous flight auger piling
Low head room continuous auger pile
Cased flight auger piling
4. What is the equipment used for driving a pre – cast pile in a sandy soil?
The equipment used for driving a pre-cast pile in a sandy soil is a
hammer. Hence maximum stresses are developed at the top due to direct
strokes and at the point in overcoming the resistance to penetration.
Therefore additional reinforcement is provided.
5. Define well foundation. What are the types of well foundation?
Well foundation is a type of deep foundation which is generally
provided below the water level for bridges. Well foundation is a box of
timber, metal, reinforced concrete or masonry which opens both at the top
and bottom, and is used for building and bridge foundations. Well
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foundations are being used in India from very early days. TajMahal was
built on such foundations.
TYPES:
Open caisson
Single wall open caisson
Cylindrical open caisson
Open caisson with dredging wells
Box caisson
Pneumatic caisson
6. What is well cap?
It is a RCC slab laid at the top of the well Steining. It transfers the
load to the Steining.
7. What are the components of well foundation?
The components of well foundations are,
Well curb
Cutting edge
Steining
8. What is a Kent ledge?
In well sinking, to overcome the increased skin friction and the in
weight of the well due to buoyancy, additional loading is applied on the
wall. It is called Kent ledge.
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9. What is cofferdam?
Cofferdams are temporary or permanent structure which is
constructed so as to remove water / soil from an area and make it possible to
carry on the construction work under reasonably dry conditions. These are
constructed by driving sheet piles in the form of cells which are filled with
granular materials and become self-stabilizing retaining structures.
10. What are the factors you will consider while selecting cofferdams?
The area to be protected by a cofferdam.
The depth of coater to be dealt with shallow depth or deep depth.
The possibility of overtopping by floods, tides, etc.
The nature of bed on which the cofferdam is to test, (i.e.) previous
layer or an impervious layer.
11. What are the uses of cofferdam?
To facilitate pile driving operations
To place grillage and raft foundations
To construct foundations for piers and abutments of bridges, dams,
locks, etc.
12. What are the types of cofferdams?
The types of cofferdams are,
Dikes
Single wall construction
Double wall construction
Cellular cofferdam
Rock filled
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Concrete cofferdam
Suspended cofferdam
13. Define shoring.
Shoring is the construction of a temporary structure to support
temporarily an unsafe structure. These support walls laterally.
14. What are the types of shoring?
Depending upon their supporting characteristics the shores are
classified into 3 categories.
Racking or inclined shores
Flying or horizontal shores
Dead or vertical shores
15. Why is shoring provided in foundation?
When a wall cracks due to unequal settlement of foundation and the
cracked wall needs repair. So, shoring is provided in foundation.
16. Under what circumstances shoring is provided?
When walls bulge out
When walls crack due to unequal settlement of foundation and repairs
are to be carried out to the cracked wall
When an adjacent structure needs pulling down
When openings are to be newly made or enlarged in a wall
17. What are the methods of providing shoring for the trenches?
Stay bracing
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Box sheeting
Vertical sheeting
Runners
Sheet piling
18. Define wales.
The depth of sheeting is held in position by means of horizontal
beams called wales.
19. Define rakes.
If the excavation is too wide, the wales may be supported by inclined
struts known as rakes.
20. Define struts.
Strut is a compression member to provide temporary support to in-situ
retaining walls in deep excavations. It is mostly a steel beam of various
sections or a pipe. Reinforced concrete beams are seldom used.
21. Define underpinning.
The process of placing a new foundation under an existing one or
strengthening and existing foundation is called underpinning.
22. What are the types of underpinning?
Pit method
Pile method
Chemical method
Other methods
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23. Define diaphragm wall.
Diaphragm wall are structure elements, which are constructed
underground to prevent the seepage into the excavated area.
24. Define RCC diaphragm wall.
Diaphragm Wall is generally reinforced concrete wall constructed in
the ground using under slurry technique which was developed in Europe.
The technique involves excavating a narrow trench that is kept full of an
engineered fluid of slurry. Walls of thickness between 300 and 1200 mm
can be formed in this way up to depths of 45 meters.
25. When is diaphragm wall used?
A diaphragm wall is basically a deep trench excavated in soil in to
which reinforced concrete is placed. Diaphragm walls are used in
permanent and temporary foundation walls for deep basements in earth
retention schemes for highway and tunnel projects, as permanent walls for
deep shafts for tunnel access, and as permanent cut – off walls through the
care of earth dams.
26. Write down the construction procedure of diaphragm wall.
Fixing of alignment
Guide wall construction
Trenching
Trench cleaning
Stop ends fixing
Reinforcement cage lowering
Placing of concrete
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Withdrawal of stop ends
27. What are the various methods adopted to construct a diaphragm wall?
Slurry trench technique
Soil mixing method
RC continuous diaphragm wall
Precast diaphragm wall
Glass diaphragm wall
28. Give the uses or applications of diaphragm wall.
Commonly used in congested areas.
Can be installed in close proximity to existing structure.
Practically suited for deep basements.
Used in conjunction with “Top Down” construction technique.
UNIT – 3
1. Define scaffolding.
These are temporary erections constructed to support a number of
platforms at different heights raised for the convenience of workers so as to
enable them to work easily and raise the needed materials.
2. What are the component parts of scaffolding?
Standards
Ledgers
Braces
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Putlogs
Transoms
Bridle
Boarding
Guard rail
Toe board
3. Give the materials used for formwork.
Formwork can be made out of timber, plywood, steel, precast
concrete, fibre glass, used separately or combination.
4. When the removable of formwork are done?
The form should be removed until the concrete has hardened
sufficiently and they may be left in place for as possible up to maximum
days of 28 in normal weather conditions. A hard metallic sound indicates
the concrete has hardened sufficiently for safe removal of formwork.
5. State briefly the essential requirements of formwork.
It should be strong enough to withstand all loads coming on it, such a
dead load of concrete and live load during its pouring, compaction and
curing.
It should be stiff enough so that deflection is minimum
It should be as be light as possible
This form work should rest on non – yielding supports
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6. Define centering and shuttering.
Part of the form work which supports the horizontal surface is called
centering for example slab bottom, beam bottom etc.
Part of the form work which supports the Vertical surface is called
Shuttering for example column sides, beam sides, slab side, wall side etc.
7. Define hoisting.
A hoist is a device used for lifting or lowering a load by means of a
drum or lift-wheel around which rope or chain wraps. It may be manually
operated, electrically or pneumatically driven and may use chain, fiber or
wire rope as its lifting medium. The load is attached to the hoist by means of
a lifting hook. There are three types of hoist namely,
Wire rope or chain hoist
Construction hoist
Mine hoist
8. Define rigging.
Rigging is the apparatus through which the force of the wind is used
to propel sailboats and sailing ships forward. This includes masts, yards,
sails, and cordage.
9. What are the types of cranes?
Overhead crane
Truck mounted crane
Side lifter crane
Rough terrain crane
All terrain crane
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Pick and carry crane
Carry deck crane
Telescopic handler crane
Crawler crane
Harbor crane
Railroad crane
Floating crane
Aerial crane
Tower crane
Level luffing crane
Gantry crane
Deck crane
Bulk handling crane
Stacker crane
10. Define plastering.
The process of covering the surfaces of masonry, beam or column
with mortar is called plastering. Mortar is a substance obtained by mixing
sand, a binding material (cement/lime) and water in definite proportions.
11. Define flooring. What are the types of flooring?
Flooring is the horizontal area in any floor of a building that is
actually the space used by the occupants for moving in the building.
TYPES OF FLOORING:
Mud flooring
Cement concrete flooring
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Terrazzo flooring
Mosaic flooring
Glazed tile flooring
Marble flooring
Linoleum flooring
Brick flooring
Stone flooring
Granolithic flooring
Timber flooring
Asphalt flooring
Rubber flooring
Epoxy resin flooring
12. What are the requirements of good flooring?
Low cost
Good appearance
Sound and thermal insulation
Strength and durability
Smoothness
Damp and fire resistance
Comfortability
Anti-skid
13. Give some aspects you consider while choosing the floor type.
Initial cost
Appearance
Cleanliness
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Durability
Damp resistance
Sound insulation
Thermal insulation
Smoothness
Hardness
Fire resistance
Maintenance consideration
14. What are the components of flooring?
Sub floor or base course
Floor covering
15. Define aggregate crushers and screening equipment.
Screening is the separation of material into 2 - 6 different sized
products. The material is separated by passing it through a vibrating 'screen
box' which a number of different has sized screens, or meshes, which the
material falls through like a sieve. The material falls onto attached
conveyors which stock piles the end products. The end products can then be
used in the building and construction industries.
16. Define aggregate feeders.
Aggregate feed bins are used for each of the size of the aggregate and
sand, and control their quality, weighting system is used for important jobs,
since control by volume is not perfect as it varies due to closeness of
packing of the material. The aggregate fed bins are loaded by any of the
following methods
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By shovels directly into the bins
By lorries tipping directly into the bins
Aggregate are stored in bulkhead at ground level
17. Define batching.
The measurement of materials for making concrete is known as
batching. There are two methods of batching.
Volume batching
Weight batching
18. What are the methods of equipment are used by volume batching?
Aggregate feeders
Cement silo
Water measuring device and
Mixing unit
19. Define mixing.
After measuring the materials required for preparing the concrete it
has to be mixed well before placing the concrete. It should ensure that the
mass becomes homogeneous and uniform. There are two methods of
mixing.
Hand mixing
Machine mixing
20. What are the methods are adopted for transportation of concrete?
Mortar pan
Wheel barrow
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Crane, bucket and rope way
Truck mixers and dumpers
Belt conveyors
Chute
Skip and hoist
Transit mixer
Pump and pipe line
Helicopter
21. What is meant by transit mixer?
Transit mixer is a piece of equipment that is used for transporting
concrete, mortar or ready mix material from a concrete batching plant
directly to the site where it is to be utilized. Transit mixer is loaded with dry
material and water. The interior of the transit drum is fitted with a spiral
blade.
22. What are the types of conveyors?
Belt conveyors
Roller conveyors
Chain conveyors
Pipe conveyors
Elevating conveyor
23. What are the advantages of using belt conveyors?
Its suitable levels eliminate a good deal of lifting and lowering of
material.
It require no stopping or standing but is continuous operation.
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Transportation is affected by friction between material being
transported and the belt.
It largely saves labor cost.
No noise
Carry the material horizontal, vertical, inclined.
It can withstand 1600 C.
24. What are the activities normally followed during concreting?
Batching
Mixing
Transporting
Placing
Compacting
Curing
25. Define compaction.
Compaction is defined as the process of densifying or increasing the
unit weight of a soil mass through the application of static or dynamic force,
with the resulting expulsion of air.
26. What are the factors influencing compaction?
Drum diameter
Frequency and amplitude
Relationship between frame and drum weight
Driven or non-driven drum
Centrifugal force
Total applied force
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Static weight
Number of vibratory drums
Roller speed
27. Name some compaction equipment.
Towed static smooth compactors
Static sheep foot or pad foot compactors
Static three wheel self-propelled compactors
Static tandem compactors
Three axle static compactors
Rubber tyred compactors
Vibrator compactors
Tandem vibrator compactors
Towed vibrator compactors
Sheep foot & tamping foot vibrator compactors
Self-propelled vibrator compactors
Hand guided vibrator compactors
28. What are the various types of concreting equipments?
Concrete mixers
Concrete hauling equipments
Wheel barrows
Dumpers
Ready mix concrete mixers
Concrete pumps for placement in different conditions
Concrete vibrators for compaction
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Poker or internal vibrator
External clamp or tamping board vibrator
29. Define shotcreting.
Mortar or high performance concrete conveyed through a hose and
pneumatically projected at high velocity onto a backing surface is known as
shotcreting.
30. How pumps are classified?
Positive displacement pump
Reciprocating pump
Rotary pump
o Gear pump
o Vance pump
o Screw pump
Rotodynamic pump
Volute pump
Circular pump
Diffuser pump
Vertical turbine pump
Centrifugal mixed flow pump
Propeller pump
31. Define drilling.
Drilling is a cutting process that uses a drill bit to cut a hole of circular
cross-section in solid materials. The drill bit is a rotary cutting tool, often
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multipoint. The bit is pressed against the work piece and rotated at rates
from hundreds to thousands of revolutions per minute. This forces the
cutting edge against the work piece, cutting off chips (swarf) from the hole
as it is drilled.
32. What are the types of drilling equipment?
Percussion drills
Rotary drills
Pressure drilling
Abrasion drilling
33. What are the factors affecting the selection of drilling equipment?
Nature of terrain
Required depth of holes
Rock hardness
The purpose for which holes are required to be drilled (i.e.) for
blasting or grouting or for exploration purposes
The size of the project
34. What are the methods used for building demolition techniques?
Manual method
Mechanical method
Demolition by machine
Demolition by hydraulic rushers
Demolition by wrecking ball
Explosive method
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35. What are the methods used for tunnel driving?
Full face method
Top Heading and benching method
Drift method
Pilot tunneling
Needle beam method
36. What are the factors you will consider while selection of route in
tunneling?
Geological conditions
Right of way
Alignment restraints
Environmental considerations
37. Give the various methods of tunneling through soft ground.
Fore poling method
Needle beam method
Five piece set method
Other methods
Casting methods
Square sets and logging method
Horse cups method
38. Give the various methods of tunneling through rock.
Full face method
Top heading and benching method
Cantilever car pump method
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Drift method
Pilot tunneling
UNIT – 4
1. Define bridges. What are the types of bridges?
A bridge is a structure constructed to provide the passage for a road or
railways over an obstacle such as river, valley etc. without closing a wall.
Masonry arch bridge
Reinforced cement concrete bridge
Slab bridge
T – beam bridge
Hollow girder bridge
Balanced cantilever bridge
RCC arch bridge
Steel bridge
Plate girder bridge
Steel arch bridge
Cable stayed bridge
Suspension bridge
Cantilever bridge
2. What are the types of sub structure?
Foundation
Abutment
Pier
Wing walls and return walls
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Revetment
Apron
Approaches to bridge
3. What are the types of super structure?
Bearings
Deck
Hand rails
Girder or truss
Roadway
4. Define abutment.
The abutment is a terminal support of the bridge. It is built on either
side of a valley where the road or railway joins the bridge.
5. Define pier.
In a multispan bridge piller like supports are constructed between the
abutments. These supports are called piers.
6. Define multispan bridge.
In a multispan bridge there are several piers and hence several spans.
The multispan bridges are built in the middle or lower reaches of rivers
where the valleys are generally very wide.
7. Define suspension bridge.
A bridge which is suspended with the help of cables and steel towers
across a deep and narrow river valley is called suspension bridge.
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8. Define RCC bridges. What are the types of RCC bridges?
Reinforced Cement Concrete is well suited for the construction of
bridges in the small and medium span ranges. Different types of RCC
bridges which are usually constructed are: Slab bridges, T – beam (girder
and slab) bridges, hollow girder bridges, balanced cantilever bridges,
continuous girder bridges, rigid frame bridges, arch bridges and bowstring
girder bridges.
9. What are factors to be considered for selection of site for bridges?
Span of the bridge and number of spans
Purpose of bridge
Intensity of loading on the bridge
Type of super structure adopted
Headroom to be provided below the bridge
Type of foundation soil, available
Nature of material used
Nature of alignment
Relative position of floor of the bridge
Prevailing wind force and earth – quake possibilities
Life expectancy of the bridge.
10. Define cable stayed bridges. What are the types of cable stayed bridges?
This type of bridge is especially suited for spans ranging from 200 to
500m. The main component of a cable stayed bridges are,
Inclined cables
Towers
Decks
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In a simple form the cables are provided above the deck and
connected to towers. This eliminates intermediate piers and provides large
width for the purposes of navigation. The deck is supported by a number of
cables. This type of bridge is widely used in recent years because of the
availability of high strength steel.
11. What are balanced cantilever bridges?
Providing continuous spans can minimize the bending moment and
hence individual span lengths can be increased. But this requires unyielding
supports. Any yielding of supports results in distress in structure. In order
to avoid this, a combination of cantilever and suspended spans may be
adopted. The bridge with this type of super structure is referred to as
balanced cantilever bridges. This type of bridge is suitable for medium span
in the range of about 35 to 60m.
12. What are the erection methods of launching of heavy deck?
Balanced cantilever erection method
Progressive placing method
Span by span (or) Steeping form work method
Incremental launching method
UNIT – 5
1. Define roads. What are the types of roads?
Road is specially prepared path on which the transport vehicles pass
lawfully.
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CLASSIFICATION OF ROADS ACCORDING TO LOCATION AND
FOUNDATION:
National highway
State highway
Major district roads
Other district roads
Village roads
CLASSIFICATION OF ROADS BASED ON MATERIALS USED:
Earth roads
Gravel road
Water Bound Macadam road
Bituminous road
Asphalt road
Cement concrete road
2. Define flexible pavements. What are the types of flexible pavements?
Flexible Pavements are those, which on the whole have low or
negligible flexural strength and are rather flexible in their structural action
under the loads. The Flexible Pavements layers reflect the deformation of
the lower layers on to the surface of the layer.
TYPES:
Conventional layered flexible pavement
Full depth asphalt pavement
Contained Rock Asphalt Mat (CRAM)
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3. Define rigid pavements. What are the types of rigid pavements?
Rigid pavements are those, which possess noteworthy flexural
strength or flexural rigidity. The stresses are not transferred from grain to
the lower layers as in the ease of flexible pavement layers. The rigid
pavements are made of Portland cement concrete either plan, reinforced or
pre-stressed concrete.
TYPES:
Jointed Plain Concrete Pavement (JPCP)
Jointed Reinforced Concrete Pavement (JRCP)
Continuous Reinforced Concrete Pavement (CRCP)
Pre-stressed Concrete Pavement (PCP)
4. What are the factors to be considered for selection of site for roads?
Type and purpose of road
Cross drainage works
Bridges
Railway crossing
Existing right of way
Public demand
Availability of material
Availability of labour
5. What is a tunnel? What are their uses?
A tunnel is an underground or underwater passageway, dug through
the surrounding soil/earth/rock and enclosed except for entrance and exit,
commonly at each end.
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USES:
Tunnels are made for highways and railway for regular traffic and
transportation of goods
Tube railways are made through tunnels
Diverting the river water through tunnels in the construction of dams
Pressure or hydropower tunnels are used in power generation
Tunnels are used for supply of drinking water, and oil or sewage
disposal or laying cables
Tunnels are made to extract minerals
Discharge tunnels to convey water from one point to another by
gravity
6. What are the advantages of tunneling?
Time saving and reduction in fuel
Avoid unwanted traffic congestion
Maintain a proper speed
Avoid tiredness of travel
Avoid unwanted accidents
To avoid deforestation and death of animal while crossing
To avoid land slide in hilly region
To avoid the long route around the mountain
To reduce the length of highway and railway and it may be
economical
7. What are the types of tunnel construction methods?
Classical method
Mechanical drilling / cutting
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Cut and cover method
Drill and blast method
Shields and Tunnel Boring Machines (TBM’s)
New Austrian Tunneling Method (NATM)
Immersed tunnels
Special methods (tunnel jacking)
8. Define cut and cover method.
Cut and cover is a simple method of construction for shallow tunnels
where a trench is excavated and roofed over with an overhead support
system strong enough to carry the load of what is to be built above the
tunnel.
9. What are the component parts of pipe jacking?
Thrust yoke
Skid base
Power packs
Intermediate jacking stations
10. What is meant by pipe jacking?
Pipe jacking is a method of installing a pipe under roadway, railway
or highways without using an open cut trench. The pipe jacking procedure
was a casing pipe of sheet or reinforced concrete (i.e.) jacked through the
soil.
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11. What are the techniques used in box / pipe jacking?
A technique used in box/pipe jacking requires the construction of just two
pits:
The thrust
Reception pits
Dimensions of the pits vary according to site conditions. Excavation
of soil can be by manual or mechanical means depending on the type of
machines used.
12. Give the applications of box jacking.
The applications of box jacking are,
Underground pipes
Ducks and culverts
13. Give the advantages of box / pipe jacking.
Environmentally friendly with minimal damage to the surface
Highly accurate and cost effective
Suitable for all kinds of profiles for a wide variety of soil conditions
Traffic congestion and additional pollution will not cause
Extremely suitable for all kinds of underground utility infrastructure.
14. List the disadvantages of box / pipe jacking.
Limited tunnel run resulting in more required shafts (approximately
every 1000ft)
Relatively straight alignment required (minimum radius of curvature
approximately 4000ft)
Difficulty in replacing damaged pipe.
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15. What are the types of cut and cover method?
Conventional method
Bottom – up method
Top – down method
Cast – in – place method
16. What is grouting?
Grouting is an engineering and art combined to fill up the voids or
cavities in rock or soil masses with fluid that will increase the overall
strength and impermeability of the mass.
17. Give the types of grouting.
Chemical
Cement
Jet grouting
18. Give the characteristics of grouting materials.
The characteristics of grouting materials are,
The grouting material has high permeability
No vibrations are used
Application requires no additional structures used
19. Explain about cement grouting.
In this method, cement grout which is a mixture of cement, sand and
water is used. The process consists of making a number of holes in ground
and then filling these holes by cement grout under pressure. This process is
continued till no grout is coming up through the hole.
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USES:
The grouting procedure can be used in stopping leakages from rock
It can also be used to fill the voids in soil so as to strengthen the soil
and to make the rock or soil water tight
20. Define TBM.
A tunnel boring machine (TBM), also known as a "mole", is a
machine used to excavate tunnels with a circular cross section through a
variety of soil and rock strata. They may also be used for micro tunneling.
They can bore through anything from hard rock to sand. Tunnel diameters
can range from a 1 meter to 19.25 meters to date.
21. List out the advantages of tunnel boring machines.
There is very less danger of fall outs in machine bored tunnels, since
adjacent or surrounding rocks are undistributed as no blasting is done.
Mucking is also safe and convenient, since muck is conveyed from the
face to the rear of the machine and is loaded automatically by means
to the rear of the machine and is loaded automatically by means of
belt conveyors.
Higher speed of excavation.
Reduction in the tunnel supports requirement.
Less manpower requirement.
22. Define shafts.
In civil engineering a shaft is an underground vertical or inclined
passageway. Shafts are constructed for a number of reasons including:
For the construction of a tunnel
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For ventilation of a tunnel or underground structure
As a drop shaft for a sewerage or water tunnel
For access to a tunnel or underground structure, also as an escape
route
23. Define tunnel lining. What are the types of tunnel lining?
The finishing touch given to the cross – section of the tunnel is known
as tunnel lining. The plain and reinforced concrete is generally used for the
lining.
TYPES:
Temporary ground support
Primary lining
Secondary lining
24. Mention the sequence of operations involved in during the tunnel
through rock.
Setting up and drilling
Loading the holes with explosives and firing
Ventilating and removing the dust resulted by explosion
Loading and hauling the muck
Removing ground water from the tunnel
Erection of supports for the roof and sides
Placing reinforcement
Placing the concrete lining
Curing and shuttering removal
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25. What are the objectives of ventilation system in a tunnel?
To provide fresh air for workers
To remove poisonous gases and fumes produced by explosion
To remove the dust caused by drilling, blasting, mucking and other
operations Performed in the tunnel.
26. Define mucking.
The operation of removal of excavated material in tunneling operation
is called mucking. Different methods of mucking are,
In small tunnels, hand carts or wheel barrows are used
Special power shovels are used in medium size tunnels which are with
a short boom and a dipper strikes.
Specially made mucking machines are equipped with dippers in large
tunnels.