Ad exam

of 43
Surveying
Survey Station: A prominent point on the chain line. Can be at the beginning of the chain line or at the
end. Known as main station.
Survey Lines: Lines joining the main survey stations. Also known as base line.
Check Line: Lines which are run in the field to check the accuracy of the work.
Tie Line: Line joins tie station on main line.
Bearing: Bearing of a line is its direction relative to a given meridian.
Level Line: Line lying in a level surface.
Horizontal Line: Straight line tangential to the level line at a point.
Vertical Line: A line normal to level line at a point.
Datum: Any surface to which elevation are referred.
Elevation: vertical distance of any surface from the datum.
Mean Sea level: Average height of the sea for stage of the tides.
Bench Mark: Relatively permanent point of reference whose elevation w.r.t. assumed datum is known.
Height of Instrument: For any set up of the level HI is the elevation of plane of sight w.r.t. assumed
datum.
Back Sight: B.S. is the sight taken on a rod held at a point of known elevation to ascertain the amount
by which the line of sight is above that point and thus to obtain the HI.
Fore Sight: F.S. is the sight taken on a rod held at a point of known elevation to ascertain the amount by
which the point is below the line of sight and thus to obtain the elevation of the station.
Turning point: Is a point on which both minus sight and plus sight are taken on a line of direct levels.
Intermediate Station: Is appoint intermediate between two turning points on which only one sight is
taken to determine the elevation of the station.
Theodolite: Theodolite is the most precise instrument designed for the measurement of horizontal and
vertical angles and has wide applicability in surveying such as laying off horizontal angles, locating
points on line, prolonging survey lines, establishing grades, determining difference in elevation, setting
out curves.
Transverse Surveying: Traversing is that type of surveying in which a number of connected survey
lines from the framework and the directions and lengths of survey lines are measured with the help of
an angle measuring instrument and a tape respectively.
Levelling: Levelling is a branch of surveying the object of which is to find the elevations of given with
respect to a given or assumed datum and to establish points at a given elevation or at different
elevations with respect to a given or assumed datum.
Reciprocal Levelling:

of 43
Classification of Surveying:
A. Based on the nature of the Field Survey:
i) Land Survey.
ii) Marine Survey.
iii) Astronomical Survey.
B. Based on the Object of Survey:
i) Engineering Survey.
ii) Military Survey.
iii) Geological Survey.
iv) Mine Survey.
v) Archaeological Survey.
C. Based on Instruments used:
i) Chain Survey.
ii) Theodolite Survey.
iii) Traverse Survey.
iv) Triangulation Survey.
v) Tacheometric Survey.
vi) Plane Table Survey.
vii) Photographic Survey.
viii) Aerial Survey.
Chaining:
Instruments of Chaining are Chain, Arrow, Pegs, Ranging Rods, Offset Rods, Plaster’s laths, Plumb
Bob.
Types of Chain:
Types Length Link
Metric Chain 5, 10, 20, 30 meters
Gunter’s Chain 66 ft 100
Engineer’s Chain 100 ft 100
Revenue Chain 33 ft 16
Error occurs in chaining:
a) Erroneous length of chain (Positive or, Negative)
b) Bad Ranging (Positive)
c) Careless holding and Marking (Positive)
d) Bad Straightening (Positive)
e) Non-Horizontality (Positive)
f) Sag in chain (Positive)
g) Variation in Temperature (Positive or, Negative)
h) Variation in pull (Positive)

of 43
Engineering Materials
Strength: The stress at which the material fails.
Brittleness: Tendency of a material to break before it undergoes plastic deformation.
Ductility: The ability of certain materials to be plastically deformed without fracture.
Malleability: The ability of a material to take a new shape when hammered or rolled.
Hardness: The resistance to deformation and forced penetration.
Elasticity: The ability to deform and return to the undeformed shape.
Compressive strength: Maximum compressive stress a material can withstand without failure.
Cursing Strength: The compressive stress required to cause a solid to fail by fracture.
Fatigue Strength: The maximum stress a material can endure for a given number of stress cycles without breaking.
Flexural strength: Strength of a material in bending.
Impact Strength: Ability of material to resist shock loading.
Shear Strength: The maximum shear stresses which a material can withstand without rapture.
Tensile Strength: The maximum tensile stress a material can withstand without rapture.
Ultimate Strength: The tensile stress per unit of the original surface area at which a body will fracture.
Yield Strength: The stress at which a material exhibits a specified deviation from proportionality of stress and
strain, that is, it indicates the end of elasticity and the beginning of plasticity.
Poison Ratio: The ratio of lateral strain to longitudinal strain.
Creep: The increase in strain under a sustained constant stress.
Fatigue: When cyclic loading is applied to a material failure of that material may occurred at much lower stress.
Toughness: Ability to withstand cracking.
Stiffness: Resistance to deform in the elastic range.
Longitudinal Strain: The ratio of change in length to original length is called longitudinal strain.
Shearing Strain: Shearing strain is defined as the angle of shear measured in radians.
Volume Strain: The ratio of the change in volume to original volume is called volume strain.
Shear: A shearing force acts p
Cement: Binding material that holds things together. Manufactured from calcareous material (limestone) and
argillaceous material (clay).

of 43
Steel:
- Deformed bar, Plain round bar, Flat bar, Tor steel bar, Square rod, Stainless square rod, Plain round rod,
Twisted round rod, Twisted rope rod, Deformed round rod
Accelerators: Admixture that decrease the setting time.
Admixture: An ingredient of concrete to control setting and early hardening, workability.
Binder: Hardened cement paste.
Calcinations: Decomposition due to the loss of bound water and carbon dioxide.
Curing: To keep concrete moist during hardening.
Gypsum: Calcium Sulphat+2H2O
Kiln: High Temperature oven.
Limestone: Mineral water.
FM (FA) =
Sieve NO. 4, 8 , 16, 30, 50, 100
100
Sieve Size Standard opening (mm)
3 9∙5
4 4∙75
8 2∙36
16 1∙18
30 0∙600
50 0∙300
100 0∙150
200 0∙075
FM (CA) =
Sieve NO. 75∙0, 37∙5 , 19, 9∙5, 4∙75, 2∙36, 1∙18, 600, 300, 150
100

of 43
Cement
Definition: Cement is a binding material that can hold things together. It is manufactured from calcareous material
(Compounds of calcium and magnesium, example Limestone) and argillaceous material (mainly silica, alumina and
oxides of iron, example Clay). Cement is binder, a substance which sets and hardens independently and can bind other
materials together.
Raw Materials:
i) Limestone
ii) Chalk
iii) Shell
iv) Calcareous mud
Basic component of Cement manufacturing process:
Basic Chemistry of Cement:
Clinker contains four main materials.
Alite: Approximately tricalcium silicate (typically about 65 % of the clinker).
Belite: Approximately dicalcium silicate (typically about 15 % of the clinker).
Aluminate: Very approximately tricalcium aluminate (typically 7 % of the clinker).
Ferrite: Very approximately tetracalcium aluminoferrite (typically 8 % of the clinker).
Main compounds in Portland Cement:
Name of Compound Oxide Composition Abbreviation
Tricalcium Silicate 3 CaO . SiO2 C3S
Dicalcium Silicate 3 CaO . SiO2 C2S
Tricalcium aluminate 3 CaO . Al2O3 C3A
Tetracalcium aluminoferrite 3 CaO . Al2O3 . Fe2O3 C4AF
Types of Cement and their Composition ASTM C 150:
Type ASTM C 150 C3S C2S C3A C4AF
I General Purpose 55 19 10 7
II Moderate sulfate resistance (and
moderate heat of hydration as option)
51 24 6 11
III High early strength 56 19 10 7
IV Low heat of hydration 28 49 4 12
V Sulfate resistant 38 43 4 9
Limestone
Blending Kiln Clinker Store Clinker Mill
Clay

of 43
Types of Cement in European Standard:
Type Composition
Portland Cement Comprising Portland cement and upto 5 % of minor additional
constituents.
Portland Composite Cement
1. Portland Slag Cement
2. Portland Silica fume Cement
3. Portland Fly-ash Cement
4. Portland Limestone Cement
5. Portland Composite Cement
Portland cement and up to 35% of other single constituents.
Blastfurnace Cement Portland cement and higher percentages of blast furnace slag.
Pozzolanic Cement Portland cement and up to 55 % of pozzolanic constituents.
Composite Cement Portland cement, blast furnace slag and pozzolana or fly ash.
Cement Hydration: The process by which cement reacts with eater is termed „hydration‟
Heat of Hydration: When cement and water are mixed together, the reactions which occur are mostly exothermic –
heat is produced. This is called heat of hydration.
Setting of Cement: Setting is used to describe the stiffening of the cement paste. Setting refers to changes of
cement paste from a fluid to rigid state.
Hardening of Cement: The term hardening refers to the gain of strength of a set cement paste, although during
setting the paste acquires some strength.
Initial Setting time: The beginning of the setting process when the cement paste starts losing its plasticity
Final Setting time: Time elapsed between the moment water is added to cement and the time when the paste
completely lost its plasticity and can resist certain definite pressure.
False Set: This refers to rapid setting that occurs without the liberation of much heat. Plasticity can be regained by
further mixing without the need to add more water
Flash Set: This behavior is accompanied by the liberation of considerable heat. The plasticity cannot be regained
with additional mixing or water.
Special Types of Cement:
1. Pozzolan – Modified Cement:
2. Slag Cement: Blends of a minimum of 70 % water quenched, Blast – furnace slag and Portland cement.
Used in hydraulic structure such as dams and bridge
3. Slag – Modified Portland Cement:
4. Expansive Cement:
5. Whit Cement:
6. Water – Repellent Cement:
7. Masonry Cement:
8. Rapid setting Cement:

of 43
Flow diagram of Dry Process and Wet process of cement Manufacture
Dry Process Wet Process
Calcareous (Limestone) Argillaceous (Clay) Calcareous (Limestone) Argillaceous (Clay)
Crushing CrushingCrushingCrushing
GrindingGrindingGrinding Grinding
WaterStorageStorage Storage Storage
Mixing, Wet Grinding in Rotary MillMixing – In – Correct Proportion
Coal/FuelCoal/Fuel Slurry formationStorage – of Raw Mix
Rotary – KilnRotary – Kiln
Clinker – Formation
GypsumClinker – Grinding
Clinker – Formation
GypsumClinker – Grinding
Packing & Distribution Packing & Distribution

of 43
Aggregates
Definition: Aggregate is inert granular material such as sand, gravel, crushed stone and brick chips that usually
occupies approximately 60 to 75% of the volume of concrete. Aggregate properties significantly affect the workability
of plastic concrete and the durability, strength, thermal properties and density of harden concrete.
Use of Aggregate:
i. Reinforcement Concrete
ii. Asphalt Concrete
iii. Base materials for Roads
iv. Ballast
v. Foundations
vi. Plaster, Mortar, Grout, Filet materials etc.
Classification of Aggregates:
A. Based on Size:
i) Fine Aggregate: They would pass through #4 sieve, retained on No. 200 (= 0·075 mm) sieve. That
means less than 4·75 mm and greater than 0·075 mm
ii) Course Aggregate: Size of this type of aggregates are 4·75 mm to 50 mm.
B. Based on source:
i) Natural: Sand, Gravel, Crushed Stone
ii) Manufactured: Blast Furnace Slag, recycled Concrete other industry by products etc.
a) Igneous Rock: Formed on cooling of the magma. Hard, tough, strong. Excellent aggregate.
Example: Granite, Basalt.
b) Sedimentary Rock: Stratified rocks. Excellent to poor aggregate. Example: Limestone, Sandstone.
c) Metamorphic Rock: Igneous or sedimentary rocks that have changed their original texture, crystal
structure or mineralogy composition due to physical and chemical condition. Example: Marble,
Schist, Slate etc.
Some important characteristics:
Oven Dry Condition (OD): All free moisture whether external surface moisture or internal moisture are
driven off by heat.
Air Dry Condition: Nor surface moisture, but some internal moisture remains
Saturated- Surface Dry Condition (SSD): Aggregate is said to be SSD when their moisture states are
such that during mixing they will neither absorb any of the mixing water add nor will they contribute any
of their contained water to the mix.
Damp or Wet Condition: Aggregate containing moisture in excess of the SSD condition.
Absorption Capacity (AC): Maximum amount of water the aggregate will absorb. The range for most
normal weight aggregate is 1 – 2 %.

of 43
AC =
WSSD − WOD
WOD
× 100 %
Effective Absorption (EA): Amount of water required to bring an aggregate from the Air Dry (AD) state
to the SSD state.
EA =
WSSD − WAD
WAD
× 100 %
Surface Moisture (SM): Amount of water in excess of SSD
SM =
WWET − WSSD
WSSD
× 100 %
It is used to calculate the additional water of the concrete mix.
Moisture content of aggregate is given by,
MC =
Wstock − WSSD
WSSD
× 100 %
Specific Gravity (SG): Specific gravity of an aggregate is the unit mass of the aggregate relative to the
mass of equal volume of water.
Soundness: Aggregate is considered unsound when volume changes in the aggregate induced by weather.
Brick
Components of Brick:
Compounds Percentage
Silica 55%
Alumina 30%
Irone Oxide 8%
Magnesia 5%
Lome 1%
Organic Matters 1%
Types of Brick:
First Class Brick, Second Class Brick, Third Class Brick, First Class Bats, Second Class Bats, Picked
Jhama Bricks, Jhama Brick, Jhama Bats.

of 43
Concrete
Durability:
Definition:
- Resistance to physical and chemical deterioration of concrete.
- Protection of embedded Steel from corrosion process.
Workability:

of 43
Transportation Engineering
Traffic Engineering Administration and Function
Function of Traffic Engineer:
- Collection, analysis and interpretation of data pertaining to traffic.
- Traffic and Transportation Planning.
- Traffic Design.
- Measures for operation of traffic.
Organization of the Traffic Engineering Department:
State highway Department
Other major Division Traffic Engineering Division Other Major Divisions
District Traffic Engineers
Supervision of signs, Signals and markings, Field Studies
and Surveys, Technical Reports, Investigate complaints,
Inspection, Assist Municipalities in making Special Surveys
and preparing Reports
Traffic
Control
Traffic
Design
Traffic Planning
and Research
Traffic surveys
and Studies
Traffic Accident
Record
Traffic Safety
Education

of 43
Traffic Engineering Administration in a Department of Transportation:
Chief Administrator
Staff Services
Planning Budget Line Department Finance Personnel
Speed, Journey Time and Delay Surveys
Spot Speed: Instantaneous speed of a vehicle at a specified location.
Running Speed: Average speeds maintained by a vehicle over a given course while the vehicle in motion.
Journey Speed: Overall travel speed; the effective speed of a vehicle between two points.
Time-mean Speed: Average of the speed measurements at one point in space over a period of the time.
Space-mean Speed: Average of the speed measurements at an instant of time over a space.
Relationship between Time-mean Speed & Space-mean Speed:
Time-mean Speed = Space-mean speed +
Standard deviation 2
Space −mean Speed
Vehicle Volume Counts
Types of Vehicle Volume Count:
1) Short-Term Counts: Determine the flow in the peak hour, Measuring the saturation flow at signalized
intersection, Intersection counts during the morning and evening peak.
2) Counts for a full a day: Determine hourly fluctuation of flow, Intersection count.
3) Counts for a full week: Determine the hourly and daily fluctuation of flow.
4) Continuous Counts: Determine the fluctuation of floe daily, weekly, seasonally and yearly, Determine
the annual rate of growth of traffic.
Police Fire Health & Welfare Transportation Public Works Parks and Recreation
Superintendent
of Transit
Service
Superintendent
Off-Street
Parking
Superintendent
of Street
Maintenance
Traffic
Engineer
Street Design
Engineer

of 43
Methods Available for Traffic Count:
(i) Manual methods
(ii) Combination of manual and mechanical methods
(iii) Automatic devices.
(iv) Moving observer method.
(v) Photographic methods.
Speed Studies
98th
Percentile Speed: The speed below which 98 percent of all vehicle travel also known as Design Speed.
85th
Percentile Speed: The speed below which 85 percent of all vehicle travel. Used for determining the speed
limits for traffic regulation.
50th
Percentile Speed: The speed at which there are as many vehicles going faster as there are going slower.
15th
Percentile Speed: The speed below which 15 percent of all vehicles travel, is used to determine the lower
speed limit.
Geometric Design
Highway Classification:
A. Urban Road:
(1) Express Ways:
(2) Arterial Streets:
(3) Sub-arterial Streets:
(4) Collector Streets:
(5) Local Streets:
B. Rural Road:
(1) National Highways:
(2) State Highways:
(3) District Highways:
(4) Village Highways:

of 43
Flexible Pavement
1. Wearing Surface:
 1 inch bituminous surface.
 Capable of withstanding wear and abrasion.
 Pavement from shoring and putting under load.
2. Base layer:
 Is a layer below wearing surface of high stability.
 It should have such character that is not damaged by capillary water and frost action.
 Composed of gravel, crushed rock or granular material treated with asphalt, cement, fly-ash.
I. Distribute the stress created by wheel to sub-grade.
II. Protect from frost action and capillary action.
3. Sub-base layer:
 Made of Granular materials.
 Necessary where sub-grade soil is extremely weak.
4. Sub-grade layer:
 It is the base layer.
 Supports all the loads which come to the pavement.
Parameter Flexible Pavement Rigid Pavement
Design precision Less precise. Design is empirical Much more precise. Basis of design is
flexural strength
Life 10 to 20 years. About 40 years.
Maintenance Frequent maintenance is necessary.
Maintenance cost is high.
Need very little maintenance.
Maintenance cost is low.
Initial cost Low. Very high.
Stage construction Allow stage construction. Does not fit into stage construction.
Availablity of Material Bitumin is low quantities and reserve is
shrinking.
Cement is in short supply but can be
manufactured.
Surface Characteristics Good riding quality and temporary skid
resistance.
Smooth and non-skid surface.
Penetration of water Permeable Impermeable except joint
Environmental condition
during construction
Hazardous effect on environment. Much less hazardous effect on
environment.
Overall economy on a life
cycle basis
For less economical Much more economical.
Wearing Coat
Prime Coat
Surface course
Base
Sub-base
Sub-Grade
Seal Coat

of 43
Marshall Mix design:
The mix design determines the optimum bitumen content. The Marshall Stability and flow test provides the
performance prediction measure for the marshall mix design method. The stability portion of the test measures
the maximum load supported by the test specimen at a loading rate of 50.8 mm/minute. Laod is applied to the
specimen till failure and maximum load is designed as stability.
Cutback Asphalt:
 When volatile solvents are mixed with asphalt cement to make a liquid product, the mixture is called
“Cutback Asphalt”.
 When a cutback asphalt are exposed to air, the volatile solvent evaporates and the asphalt in the
mixture regain its original characteristics.
 Depending on the volatility of the solvent used, the rate of curing of cutback asphalt can vary from a
few minutes to several days. Three type of cutback asphalts are:
1) Rapid-curing (RC): Gasoline or naphtha.
2) Medium-curing (MC): Kerosene.
3) Slow-curing (SC): Road oils.
Emulsified Asphalt:
 A mixture of asphalt cement, water and an emulsifying agent.
 Ranging around 3µ in size.
 Two types of emulsified asphalts are:
1) Anionic Emulsion:
- Carry negative charge.
- Effective in coating electropositive aggregate like limestone.
2) Cationic Emulsion:
- Carry positive charge.
- Effective in coating electronegative aggregate like siliceous aggregate.

of 43
REQUIREMENT OF A PAVEMENT:
An ideal pavement should meet the following requirements:
Sufficient thickness to distribute the wheel load stresses to a safe value on the sub-grade soil.
Structurally strong to withstand all types of stresses imposed upon it.
Adequate coeffcient of friction to prevent skidding of vehicles.
Smooth surface to provide comfort to road users even at high speed.
Produce least noise from moving vehicles.
Dust proof surface so that traffic safety is not impaired by reducing visibility.
Impervious surface, so that sub-grade soil is well protected.
Long design life with low maintenance cost.
Air Void, percent VMA, percent
VFA, percent Unit Weight, pcf
Stability, pounds Flow, 0·01 in
Asphalt Content, percent Asphalt Content, percent

of 43
FACTORS AFFECTING PAVEMENT PERFORMANCE:
There are numerous factors influencing the performance of a pavement, the following five are
considered the most influential:
 Traffic : Traffic is the most important factor influencing pavement performance. The
performance of pavements is mostly influenced by the loading magnitude, configuration
and the number of load repetitions by heavy vehicles. The damage caused per pass to a
pavement by an axle is defined relative to the damage per pass of a standard axle load,
which is defined as a 80 kN single axle load (E80).
 Moisture : Moisture can significantly weaken the support strength of natural gravel
materials, especially the subgrade. Moisture can enter the pavement structure through
cracks and holes in the surface, laterally through the subgrade, and from the underlying
water table through capillary action. The result of moisture ingress is the lubrication of
particles, loss of particle interlock and subsequent particle displacement resulting in
pavement failure.
 Subgrade: The subgrade is the underlying soil that supports the applied wheel loads. If the
subgrade is too weak to support the wheel loads, the pavement will flex excessively which
ultimately causes the pavement to fail. If natural variations in the composition of the
subgrade are not adequately addressed by the pavement design, significant differences in
pavement performance will be experienced.
 Construction quality : Failure to obtain proper compaction, improper moisture conditions
during construction, quality of materials, and accurate layer thickness (after compaction) all
directly affect the performance of a pavement. These conditions stress the need for skilled
staff, and the importance of good inspection and quality control procedures during
construction.
 Maintenance : Pavement performance depends on what, when, and how maintenance is
performed. No matter how well the pavement is built, it will deteriorate over time based
upon the mentioned factors. The timing of maintenance is very important, if a pavement is
permitted to deteriorate to a very poor condition.

of 43
ADVANTAGE & DISADVANTAGE of FLXIBLE PAVEMENT:
Advantage:
1. Design is empirical.
2. Life time is 10 to 20 years.
3. Initial cost is less.
Disadvantage:
1. Hazardous effect on environment.
2. Maintenance cost is high.
3. Expensive than rigid pavement.
4. Manufacturing materials are not available.
RIGID PAVEMENT LAYER:
This section describes the typical rigid pavement structure consisting of:
Surface Course: This is the top layer, which consists of the PCC slab.
Base Course: This is the layer directly below the PCC layer and generally consists of
aggregate or stabilized subgrade.
Subbase Course: This is the layer (or layers) under the base layer. A subbase is not
always needed and therefore may often be omitted.
ADVANTAGE & DISADVANTAGE of RIGID PAVEMENT:
Advantage:
1. Long life time about 40 years.
2. Less hazardous effect on environment.
3. Low maintenance cost.
4. Economical than Flexible pavement.
5. Materials are not available.
Disadvantage:
1. High initial cost.
2. Does not fit into stage construction.

of 43
Environmental Engineering
Component of Water supply system:
Common Water treatment Methods are:
- Plain sedimentation.
- Sedimentation
- Filtration
- Disinfection.
Some common treatment method:
Safety range of different impurities of Water
Parameter Bangladesh Standard Treatment method
PH 6∙5 - 9∙2
Turbidity 25 (NTU) Plain Sedimentation
Color 30 (TCU) Use Alum
Hardness 200-500 (as 𝐶𝑎𝐶𝑂3) Water softening + Recarbonation
Iron 1 mg/L Prechlorination + Activated carbon
Manganese 0∙1 mg/L Prechlorination + Activated carbon
Arsenic 0∙05 mg/L Prechlorination + Activated carbon
Carbon-dioxide 50 mg/L Aeration
BOD5 10 mg/L Prechlorination + Activated carbon
Coagulation:
- Process of adding salt which produce positive ions in water.
- Application is rapid agitation for good mixing (Destabilization of colloids and promotion of frequent contact
among particle).
Flocculation:
- Gentle and continuous stirring for agglomeration of micro-flocs formed during the coagulation process to
produce larger flocs with good setting characteristics.
Intake
Pump
Collection System
Source of Supply
Treatment
Distribution System

of 43
Turbidity:
 Due to presence of suspended solid materials like clay, silt.
Odor:
 Caused because of presence of Dissolved gas (H2S).
PH
, Acidity, Alkalinity:
 They are not impurities but they disturbed in the purification process of water. So these parameters
should be controlled.
Chloride:
 High concentration of chloride in water gives an undesirable taste to water and give corrosive nature to
metal.
Infiltration: It is the water that leaks into sewers from the ground.
Inflow: It is the water which enters into sewers from surface sources through cracks in manholes, open
cleanout, perforated manhole covers and roof, drains or basement sumps connected to the sewers. Inflow
occurs only during runoff events.
Total Carbon
Inorganic Carbon Organic Carbon
Particulate Dissolved Purgeable organic Carbon Non-Purgeable organic Carbon

of 43
Sewer
Sewer: A sewer is a pipe or conduit, generally closed but normally not flowing full, for carrying
sewage. Classification of sewer on the basis of the type of sewage it carries:
1. Sanitary sewer.
2. Storm sewer.
3. Combined sewer.
Sanitary sewer: A sanitary is one that carries sanitary sewage is designed to exclude storm
sewage, surface waste and groundwater. Usually it will carry industrial wastes produced in
the area that it sewers. Its occasionally called a separate sewer.
Storm sewer: A storm sewer carries storm sewage, including surface runoff and street wash.
Combined sewer: A combined sewer is designed to carry domestic sewage, industrial waste
and storm sewage.
A sewer system composed of combined sewers is known as a combined system, but if the storm sewage is
carried separately from the domestic and industrial wastes, it is said to be a separate system.
Types of sewers that make up a waste water collection system (starting with the smallest and proceeding to
the largest) may be described as followed:
1. House or building sewers.
2. Lateral or branch sewers,
3. Sub-main sewers,
4. Main or trunk sewers,
5. Intercepting sewers,
6. Relief sewers.
Manning‟s equation for sewer design:
Q = Awetted × V
Where, V = velocity =
1
n
R
2
3 S
1
2
n = Manning‟s roughness co-efficient.
S = slope
R = Hydraulic radius =
Wetted area
Wetted perimeter
=
Awetted
Pwetted
Equation for Storm Sewage Flow:
Q = KICA
Where , Q = storm sewage flow
A = area of the catchment
C = co-efficient of runoff

of 43
I = Rainfall intensity =
a
b+t
a & b = constant
t = time of concentration (min)
Value of „K‟ & unit of „Q‟ depends on unit of „A‟ & „I‟ .
Unit of „A‟ Unit of „I‟ Value of „K‟ Unit of „Q‟
m2
ms−1 1 m3
/sec
Acre inch/hour 1 ft3
/sec
km2 mm/hour 0∙278 m3
/sec
Hector mm/hour 0∙00278 m3
/sec
Sewer system requires:
Manhole: Manhole are used as a means of access for inspection and cleansing of sewers. They are
placed:
1. At intervals of 90-150 m.
2. At points where there is a change of direction of sewers.
3. At change in pipe sizes.
4. At considerable change in grade.
5. At meeting points of two or more sewers.
Inlet:
 Inlet is an opening for entrance of storm runoff.
 They are placed usually at street intersections.
Catchment basin:
 Catchment basin is an inlet with a basin which allows debris to settle out.
 The water held in basin frequently produces mosquitoes and may itself be a source of odour.
So, they must be cleaned frequently.
Regulator:
 A regulator is a device that diverts sewage flow from one sewer into another.
Inverted Siphon:
 In sewage works the term inverted siphon is applied to a portion of sewer to avoid obstruction
such as a railway cut or a stream etc.
Sewer outlet: Sewer extended long distance in disposal points to discharge sewage which is
called sewer outlet.

of 43
Geotechnical Engineering
 Rock: Natural aggregate of mineral grains connected by strong and permanent cohesive forces.
 Soil: Natural aggregate of mineral grains with or without organic constituents that can be separated by gentle
mechanical means.
 Purpose of identification and classification:
Types Size (mm)
Gravel > 4∙75
Coarse Sand 4∙75 to 2∙00
Medium Sand 2∙00 to 0∙425
Fine Sand 0∙425 to 0∙075
Fines (Silt + Clay) < 0∙075
 Identification of Fine-grained soil fractions from Manual Tests:
Typical Name Dry strength Dilatancy
Reaction
Toughness of Plastic
thread
Times to settle in
Dispersion Test
Sandy Silt None to Very Low Rapid Weak to friable 30 sec – 60 min
Silt Very Low to Low Rapid Weak to friable 15 min – 60 min
Clayey Silt Low to Medium Rapid to Slow Medium 15 min – Several hours
Sandy Clay Low to High Slow to none Medium 30 sec – Several hours
Silty Clay Medium to High Slow to None Medium 15 min – Several hours
Clay High to Very High None Tough Several hours – Days
Organic Silt Low to Medium Slow Weak to friable 15 min – Several hours
Organic Clay Medium to Very High None Tough Several hours – Days
 Soil Moisture Scale:
Soil-Moisture Scale Physical State Consistency
Liquid Very Soft
Liquid Limit ………………………………………………………………………………… Soft
Plasticity Index, Semisolid Stiff
Plastic Range
Plastic Limit..………………………………………………………… ……………………….. Very Stiff
Shrinkage Limit……………………………………………………………………………… Extremely Stiff
Solid
Air Dry……………………………………………………………………………………….. Hard
Hygroscopic moisture
Oven Dry

of 43
 Permeability of Soil :
A material is said to be permeable if it contains continuous voids.
 Permeability of Rock:
Range 10− 8
to 10− 10
cm/second
Sample SPT qu (t.s.f)
Very Soft 0 - 2 0 - 0·25
Soft 2 - 4 0·25 - 0·50
Medium Stiff 4 - 8 0·50 - 1·0
Stiff 8 -15 1·0 - 2·0
Very Stiff 15 - 30 2·0 - 4·0
Hard > 30 > 4 · 0
 Effective Pressure: An excess over the neutral stress and acts exclusively between the points of contact of solid
constituents.
 Pore-water pressure: Acts in the water and in the solid in every direction.
 Seepage:
 Flow Net:
 Consolidation: A process which involves in decreasing of water content of a saturated soil without replacement of
water by air.
Past pressure > Present pressure = Pre-consolidation.
Past pressure < Present pressure = Consolidated soil.
 Relationship between Void ratio, Water content and Unit weight:
Vv = Volume of Voids
Vs = Volume of solid matter
V = Total volume of solid
Vw = Volume of water
e = Void Ratio =
Vv
Vs
n . s = Porosity =
Vv
V
s = Degree of Solution =
Vw
Vv
× 100%
γb
= Bulk unit weight = Unit weight of soil + the weight of water
γs
= Saturated unit weight of soil if water fills up all the voids
γd
= Dry unit weight = unit length of oven dried sample.
e =
Vv
Vs
=
Vv
V−Vv
=
Vv
V
V
V
−
Vv
V
=
n
1−n
n=
Vv
V
=
Vv
Vs + Vv
=
Vv
Vs
Vs
Vs
+
Vv
Vs
=
ev
1+e
 Relation between Total pressure, Pore water pressure, Effective Pressure:
P = Peffective + uw

of 43
 Objective of Soil Exploration:
1. To get preliminary idea about the soil (silt or clay).
2. To get the knowledge about properties of the soil.
3. To determine the bearing capacity of soil (high or less).
4. To select an economical and safe foundation for the structure (Shallow, Deep or Combined).
5. To fix the depth of the foundation.
6. To predict the settlement of the selected foundation.
7. To know the underground water level.
8. To identify which problem can be generate during construction.
 Open test method:
 Another method of subsurface exploration is open pit method.
 Dug with a backhoe or power shovel.
 An ordinary backhoe with a reach of 3 m to 4 m is usually adequate for this test.
 Most dependable and informative methods of investigation.
 It permits detailed examination of the soil formation for the entire depth.
 Stiffness of strata, the texture and grain size of the soil, detailed sampling, moisture evaluation
are some of the items of information that can be conveniently obtained from this method.
 Advantage:
1. It provides a vivid picture of the stratification
2. It is relatively fast and inexpensive.
3. It permits reliable in-place testing and sampling
 Disadvantage:
1. Applicable foe shallow depth generally 4 to 5 m.
2. High water table limit the depth of excavation.
3. If extraordinary safety is required then cost may be unacceptably high.
4. Backfilling of holes under controlled compaction condition may produce serious non-
uniform stratum characteristics over site.
 Standard penetration test (SPT) or Penetrometer test:
 Performed to determine the SPT value.
 Penetrometer is used to determine for this test.
 Penetrometer is a hand-operated device which produces the necessary force to push a probe at a
certain distance.
 Procedure:
I. A hammer of 18 inch height and 64 kg weight is allow to fall from a height of 30 inch
over the soil of the site.
II. Number of blow for each 6 inch penetration of soil is recorded.
III. Same procedure is repeated for two more 6 inch penetration.
IV. If, N2 = number of blow for 2nd
„6 inch‟ penetration and
N3 = number of blow for 3rd
„6 inch‟ penetration
Then, SPT value = N2 + N3
 SPT value „6‟ indicates the satisfied soil condition for shallow foundation.
 SPT value „16‟ indicates very good soil condition.
 Used to determine the relative density of sands and non-cohesive soils
 Not recommended for cohesionless soil.

of 43
 Disturbed Soil Sample:
Samples those are obtained by wash boring and transported out by water & deposited in a tub or
container is termed as disturbed soil sample.
 Undisturbed Soil Sample:
Samples those are obtained by pushing shell by tube smoothly & continuously into the soil with less
disturbance & so they retain in almost their original state is known as undisturbed soil sample.
 Difference between disturbed & undisturbed soil sample:
Disturbed soil sample Undisturbed soil sample
Samples are obtained by wash boring. Samples are obtained pushing shell by tube smoothly
and continuously.
Has various strata characteristics. As moisture cannot be escaped uniform
characteristics are obtained.
Less expensive & easier processes are used to obtain
those samples.
Expensive & much complex processes are used to
obtain those samples.
General information are obtained Specific information are obtained
 Reasons for selecting DEEP FOUNDATION:
1. Heavy load: When the structure has heavy load.
2. Poor bearing capacity: When the soil of the site very small bearing capacity.
3. Physical restriction: When it is impossible to increase the length of shallow foundation because
of boundary restriction.
4. Economical restriction: When shallow foundation is more costly then deep foundation.
For these types of problem we have to select deep foundation.
 Characteristics of deep foundation:
1. High bearing capacity.
2. More reliable then shallow foundation.
3. Expensive than an ordinary spread footing.
 Common form of deep foundation:
Two most common forms of deep foundation are:
1. Piles.
2. Caissons.

of 43
 Pile:
 Specially installed, relatively slender columns used to transmit the structural loads to a lower,
firmer soil or rock formation.
 Diameter is generally 750 mm or less.
 Used when simple spread foundation at a suitable depth is not possible because of required
bearing capacity.
 In incompressible soil or water-logged soil piles are used to provide safe foundation.
 Types of Pile:
Three types of piles are:
1. Timber Piles
2. Concrete Piles
3. Steel Piles
 Consideration to selection of the Pile type:
1. Corrosive property of stratum.
2. Fluctuation in the water table.
3. Installation procedure.
4. Required length.
5. Availability of material.
6. Install equipment.
7. Restriction on driving noise.
8. Costs.
 Timber Pile:
 This type of piles is made from timber.
 Timber is made from tree trunks with the branches
 May be circular or square in cross-section.
 Installed by driving.
 Normally pile is driven with small end.
 Maximum length is 20 m in normal.
 Advantages:
I. Economical
II. Can be driven rapidly which is time consuming.
III. Available
IV. For the elasticity property, this type of pile is recommended for sites where piles are
subjected to unusual lateral forces.
V. Do not need heavy machinery and elaborate technical supervision.
 Disadvantages:
I. Must be cut off below the permanent ground water level to prevent them from decay. So
this type of pile has restricted length and depth.
II. Cannot be driven in filled up ground without injury.
III. Could be attacked by insects.
IV. Liable to decay.
V. For its restricted length, this type of pile cannot be used for long pile where it is needed.
VI. Low bearing capacity.

of 43
 Steel Pile:
 Steel piles are usually rolled or fabricated in shape.
 Very strong pile.
 Expensive.
 Corrosion is the main problem of this type of pile.
 Can be attacked by corrosive agents like salt, acid, moisture or oxygen.
 Not recommended for the soil which has a pH
value less than 7.
 Concrete Pile:
 Advantages:
I. Durability of concrete pile is independent of the ground water.
II. Greater bearing capacity.
III. Can be cast to any length, size or shape.
IV. Materials are available.
V. Can be used as protective coating for steel pile.
 Disadvantages:
I. More costly then timber piles.
II. Installation is not easy.
III. Must be reinforced to withstand handling stresses.
 Types of Concrete Pile:
1. Pre-cast Pile:
 Reinforced pile which is moulded in circular, square or rectangular form.
 Piles are cast and cured in a casting yard and then transported to site.
 Length is limited to about 25 m.
 Diameter is limited to 0·5 m.
 Pile capacity is usually limited to about 75 tons.
 Used in marine installation.
 Advantage:
 Can be cast well before the commencement of the work.
 Construction can be well supervised.
 Defect can be rectified before use.
 Reinforcement remains in their proper position.
 Can be driven under water.
 Disadvantage:
 They are heavy and difficult to handle and transport.
 Exact length of a pile can rarely be pre-determined so it has to be lengthened which is
very difficult.
 If a pile is found to be too long after driving then its need to be cut down which needs
more labour, time or expense.

of 43
2. Cast in situ Pile:
 Installation is consists of driving a steel tubing or casing into the ground and then
filling it with concrete.
 Alternatively concrete may be cast into a driven shell that is subsequently extracted as
the concrete is poured
 Depending on wall thickness a steel shell or pipe may be driven with or without the
aid of a mandrel.
 Mandrel is used to prevent collapse and buckling of shell.
 Advantages:
 Can be cast in desired length.
 High load bearing capacity.
 No transportation cost.
 Saving of time required for curing.
 Pile can be designed according to exact load bearing capacity.
 Disadvantage:
 Cannot be used under water.
 Possibility of displacement of reinforcement if provided.
 As concrete is dumped from great height the quality of work is not appreciably good.
 Concrete is more susceptible to attack by corrosive constituents in soil.
 Possibility of the void being left inside the concrete.
Caisson
Caisson used when:
1. Structure moving vertically.
2. When building settle but utilities do not.
- Occurs when parts of building settle at different rates which -
a) Create cracks in structure
b) Affects the structural integrity of the building
c) Some rare cases soil may swell and pushing building upward.
Caisson is
1. Prefabricated hollow box or cylinder.
2. At first it sunk into the ground at some desired depth and then filled with concrete.
3. Used in bridge piers and structures where foundation is required under water.
4. Can be floated to the job site and sunk into place.
5. Similar to pile in formation but different in installation.
6. A form of deep foundation which are constructed above ground level, then sunk to the
required level by excavating or dredging material in caisson.
7. Consists of concrete columns constructed in cylindrical shafts.
8. Carry the building loads at their lower ends which are bell-shaped.

of 43
Types:
1. Box Caisson.
2. Excavated Caisson.
3. Floating Caisson.
4. Open Caisson.
5. Pneumatic Caisson.
6. Sheeted Caisson.
Advantages:
1. Economic.
2. Minimize requirement of pile cap.
3. Slightly less noise and reduced vibration.
4. Easily adaptable to varying site condition.
5. High axial and lateral loading capacity.
Disadvantages:
1. Extremely sensitive to construction procedures.
2. Not good for contaminated sites.
3. Lack of construction Expertise.
4. Lack of qualified Inspectors.
Types of Foundations and Methods of Construction
Footing:
An enlargement of the base of a column or wall for the purpose of transmitting the load to the subsoil at a pressure
suited to the properties of the soil.
1) Individual, Isolated, Spread Footing: Support a single column.
2) Wall or Continuous Footing: The footing beneath a wall.
3) Combined Footing: A footing supports several Column.
4) Cantilever Footing: A special type of combined footing if one of the columns supports an exterior wall.
Raft Foundation:
A combined footing that covers the entire area beneath a structure and supports all the walls and columns.
When individual footing covers more than half the building area raft foundation is used.
Pile Foundation:
Piles are underground structural members of small cross-section compared to their depth which can carry a heavy
load.
Used when footing and raft foundations are too weak.
Timber Pile, Concrete Pile, Composite Pile.
Pier Foundation:
Pier is an underground structural members used for transmitting load to a stratum capable of supporting it without
danger of failure. Ratio of Depth of foundation to the base width of piers is usually greater than 4.

of 43
Pier Shafts:
A pier is the support usually of concrete or masonry for the superstructure of a bridge.
Retaining Walls:
A structure that provides lateral support for a mass of soil and that owes is stability primarily to its own weight
and to the weight of any soil located directly above its base.
Abutments:
Pier shaft located at the end of a bridge and subjected to lateral earth pressure is known as abutment.
 Ditches and Sumps:
 Well Points:
 Sand Drains:
 Shoring:
 Bracing:
 Underpinning:
Plasticity Index = Liquid Limit – Plastic Limit
Toughness Index =
Plasticity Index
Flow Index
Atterburg Limit
Behavior of the soil is related to the amount of water in the system.
Liquid Limit Boundary between Liquid to Plastic state
Plastic Limit Boundary between Plastic to Semi-solid state
Shrinkage Limit Boundary between Semi-solid to Solid state
Terzaghi Equation:
Long Footing:
qu = C Nc + q Nq +
1
2
. B . γ . Nγ
Square Footing:
qu = 1·3 C Nc + q Nq + 0·4 . B . γ . Nγ
Circular Footing:
qu = C Nc + q Nq + 0·3 . B . γ . Nγ

of 43
Meyerhof’s Equation:
qu = C Nc sc dc ic + q Nq sq dq iq +
1
2
. B γ sγ dγ iγ
Pre measure,
B
L
=
D
B
=
kp = tan2
45 +
φ
2
C = cohesion [given]
Nc = constant [based on φ]
sc = 1 + 0·2 kp .
B
L
dc = 1 + 0·2 kp .
D
B
ic = 1 −
α
90˚
2
q = based on position of water table
Nq = constant [based on φ]
sq = 1 + 0·1 kp .
B
L
dq = 1 + 0·1 kp .
D
B
iq = 1 −
α
90˚
2
B = width or base of footing.
γ = varies with position of water table
sγ = 1 + 0·1 kp .
B
L
dγ = 1 + 0·1 kp .
D
B
iγ = 1 −
α
φ
2
B
B γ = 𝛾 𝑏
𝛾 𝑏 = 𝛾 − 𝛾 𝑤

of 43
Ultimate load,
Qu = Qp + Qs
⇒ Qu = qp . Ap + qs . As
⇒ Qu = qp .
π
4
. B 2
+ qs . π B L
Where,
qp = C Nc + q Nq +
1
2
. B . γ . Nγ
qs = ks σ tan δ
1. For Pre cast pile:
qp = 40
N L
B
≤ 400 N
qs = 2 N
2. For Cast in situ Pile:
qp = 20
N L
B
≤ 200 N
qs = N
ks = 1·5 for concrete
σ =
q
2
𝛿 = Angel of friction
L
B

of 43
Water Resource Engineering – İİ
Open Channel Flow: Flow of water in a conduit with a free surface. Free surface flow.
Prismatic Channel: Channels with unvarying cross-section and constant bottom slope.
Non Prismatic Channel: Channels with varying cross-section or varying bottom slope or both.
Small and Large slope Channels: Bottom slop less or equal to 1 in 10 or; less or equal to 6°.
Wide Channel: b≥ 10h.
Reynolds Number: Effect of Viscous force relative to Inertial force. Re =
Inertial forces
Viscous forces
=
UR
υ
Re < 500 flow is laminar, Re >12000 flow is turbulent. 500 < Re < 12000 flow is transitional.
Froude Number: Effect of the Gravity forces relative to the Inertial forces. Fr =
Intertial forcess
Gravity force s
=
U
g D
Fr = 1 flow is critical, Fr < 1 flow is subcritical, Fr > 1 flow is supercritical.
Steady Flow: Depth of flow, Mean velocity and Discharge remains same with time
Unsteady Flow: Depth of flow, Mean velocity and Discharge changes with time
Uniform Flow: Depth of flow, Mean velocity and Discharge remains same along the length of the channel.
Varied Flow: Depth of flow, Mean velocity and Discharge changes along the length of the channel. Friction losses
in gradually varied flow are not significantly different from those in uniform flow.
Specially Varied Flow: Discharge varies along the length of the channel resulting from lateral addition and
withdrawal of water.
Continuity Equation:
 Obtained from principle conservation of mass.
 For steady flow there cannot be any of storage of mass within control volume; flow must be continuous
Difference between Energy equation and Bernoulli Equation is friction loss.
Specific energy curve:
 Variation of specific energy with depth for given section and a constant discharge.
 At the critical state of flow, the specific energy is minimum for a given section.
 E-h curve is almost vertical near the critical state and small changes in E results in a large change in h.
Control: Any feature which produces a direct relationship between the depth and the discharge is control.
 Subcritical flow is subjected to downstream control
 Supercritical flow is subjected to upstream control.
Transition: A transition may be defined as a change either in the direction or slope or cross-section of the channel.
When uniform flow occurs in a channel, the component of the gravity forces causing the flow is equal to the force
of the friction or resistance.
Laminar or viscous Sublayer: Even in a turbulent flow, there is very thin later near the boundary in which flow is
laminar as known as the laminar or viscous sublayer, 𝛿 𝑣
Hydraulically Smooth Boundary:
𝑢∗ 𝑘 𝑠
𝜐
≤ 5 and 𝑘 𝑠 < 𝛿 𝑣
Hydraulically Rough Boundary:
𝑢∗ 𝑘 𝑠
𝜐
≥ 70 and 𝑘 𝑠 < 𝛿 𝑣
Transition Boundary: 5 <
𝑢∗ 𝑘 𝑠
𝜐
< 70
Chezy Formula: U = C 𝑅
1
2 𝑆𝑓
1
2 Resistance factor, C varies from 30 𝑚
1
2
𝑠 to 80 𝑚
1
2
𝑠
Darcy-Weisbech Formula: U =
8 𝑔
𝑓
𝑅
1
2 𝑆𝑓
1
2 Friction factor, f = 0∙025
Manning Formula: U =
1
𝑛
𝑅
2
3 𝑆𝑓
1
2 Manning‟s Roughness Coefficient = n 𝑠
𝑚
1
3

of 43
C =
1
𝑛
𝑅
1
6
𝐶
𝑔
=
8
𝑓
n = 𝑅
1
6
𝑓
8 𝑔
Strickler Formula for estimating Manning‟s n =
𝑑50
1
6
21∙1
Advantages of Strickler Formula:
i. Relates n with the size of the grains which can be measured easily.
ii. Since 𝑑50 is raised to 1/6 th power, an error in estimating its value has a less effect.
Minimum Permissible Velocity: Lowest mean velocity of flow that will prevent sedimentation and vegetative
growth.
Maximum Permissible Velocity: Highest mean velocity of flow that will not cause erosion of the channel body.
Freeboard: Vertical distance between the top of the channel and the water surface at the design condition.
Freeboard is varying from 5% to 30% of the depth of the flow.
Best Hydraulic Section: A channels that conveys the maximum discharge for a given area.
Best hydraulic rectangular section is one-half of a square.
Best hydraulic trapezoidal section is one-half of a regular hexagon.
Threshold Condition: Threshold Condition or impending motion condition denotes the limiting condition at which
the sediment particles just began to move.
Regime Channels: A channels is said to be in a regime when it has adjusted its shape and slope to an equilibrium
condition.
Types of bottom slopes:
i. Mild (𝑆0 < 𝑆𝑐 ; 𝑕 𝑛 > 𝑕 𝑐)
ii. Critical (𝑆0 = 𝑆𝑐 ; 𝑕 𝑛 = 𝑕 𝑐)
iii. Steep (𝑆0 < 𝑆𝑐 ; 𝑕 𝑛 < 𝑕 𝑐)
iv. Horizontal (𝑆0 = 0)
v. Steep (𝑆0 < 0)
Types of flow profile:
i. Zone 1: Space above upper line ( h > 𝑕 𝑛 ; h > 𝑕 𝑐)
ii. Zone 2: Space between two lines (𝑕 𝑛 > h > 𝑕 𝑐 or 𝑕 𝑐 > h > 𝑕 𝑛)
iii. Zone 3: Space between channel bed and lower line (h < 𝑕 𝑛 ; h < 𝑕 𝑐)
Behavior of flow profiles at specific Depths:
i. h → hn: Flow profile approaches the normal depth line tangentially.
ii. h → hc: Flow profile becomes vertical in crossing the critical depth line.
iii. h → 𝛼: Flow tends to be horizontal
iv. h → 0: Channel is wide.
Hydraulic Jump: A phenomenon in which flow changes abruptly from supercritical to subcritical and the depth
changes abruptly from a lower value to higher value.
Types of Jump:
1. Undular Jump: 1 < Fr < 1∙7
2. Weak Jump: 1∙7 < Fr < 2∙5
3. Oscillating Jump: 2∙5 < Fr < 4∙5
4. Steady Jump: 4∙5 < Fr < 9∙0
5. Strong Jump: Fr > 9∙0
h = Actual depth of gradually varied flow
hn = Normal depth
hc = Critical depth

of 43
Fluid Mechanics
Fluid Mechanics: Branch of Civil Engineering deals with behavior of fluids at rest and in motion.
Viscosity: Resistance to angular or shear deformation.
Compressibility: Compressibility of fluid is inversely proportional to its bulk modulus of elasticity.
Cohesion: Property of fluid by which molecules of same fluid particles are attracted.
Adhesion: Property of fluid by which molecules of different liquids are attracted.
Capillarity: when a tube of small diameter is dipped in water wets the tube and rises up in the tube with an upward
concave surface. This is because of adhesion between the tube and the water molecules is more than the cohesion
between water molecules. This phenomenon I s called as Capillarity.
Pascal‟s Law: Pressure at a point in a fluid at rest has the same magnitude in all direction.
Gage pressure: Pressure measured relative to the local atmospheric or barometric pressure is known as gage
pressure.
Absolute Pressure: Pressure measured with the absolute zero as a datum is called the absolute pressure.
Manometers: Devices that employ liquid columns to determine pressure or difference in pressure.
Types of manometers are piezometer, U-tube manometer.
Buoyant Force: A body immersed partially or fully in a fluid experiences a vertical upward force known as the
buoyant force. The buoyant force is vertical and acts through the center of gravity of the displacement fluid.
Archimede‟s principle: When a body is immersed wholly or partly in a fluid, it is buoyed up by a force equal to
the weight of the fluid displaced by the body.
Metacentric height: Whenever a body, floating in a liquid, is given a small angular displacement, it starts
oscillating about some point. This point about which the body starts oscillating is called metacenter.
GM = BM + BG
Path Line: The path traced by a single fluid particle in motion.
Stream Line: The imaginary line drawn in the fluid such that tangent at any point on the lines indicates the
direction of velocity of the fluid particle.
Streamtube: An element of fluid bounded by a number of stream lines which confine the flow is called a
streamtube.
Flow Net: Graphical Representation of stream lines and potential lines.
Bernoulli‟s Equation: In a steady flow of frictionless incompressible fluid, the total energy remains same.
Limitation: Flow is steady, Velocity uniform, Friction losses are zero, Fluid is incompressible, No other forces
except gravity and pressure forces are involved.
Prototype: Actual object
Model: Small size prototype.
Rayleigh and Buckingham‟s method are methods of dimensional analysis.
Reynold Number =
𝐼𝑛𝑡𝑒 𝑟𝑡𝑖𝑎 𝐹𝑜𝑟𝑐𝑒
𝑉𝑖𝑠𝑐𝑜𝑢𝑠 𝐹𝑜𝑟𝑐𝑒
Froude Number =
𝐼𝑛𝑡𝑒𝑟𝑡𝑖𝑎 𝐹𝑜𝑟𝑐𝑒
𝐺𝑟𝑎𝑣𝑖𝑡𝑦 𝐹𝑜𝑟𝑐𝑒
Weber Number =
𝑆𝑢𝑟𝑓𝑎𝑐𝑒 𝑇𝑒𝑛𝑠𝑖𝑜𝑛 𝐹𝑜𝑟𝑐𝑒
Euler Number =
𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝐹𝑜𝑟𝑐𝑒
Mack Number =
𝐸𝑙𝑎𝑠𝑡𝑖𝑐 𝐹𝑜𝑟𝑐𝑒
Laminar Flows: A flow in which the viscous forces are strong relative to the inertial forces.
Turbulent Flow: A flow in which the viscous forces are weaker relative to the inertial forces.

of 43
Pre Stressed Concrete
Question #1: What is Pre-Stressed Concrete?
Ans.: Concrete in which there have been introduced internal stresses such magnitude of distribution
that the stresses resulting from the given external loading are counteracted to a desire degree is known
as pre-stressed concrete.
Question #2: What are the concepts / fundamentals of Pre-Stressed concepts?
Ans.: There are three concepts of Pre-Stressed concrete:
1) Pre-Stressing to transform concrete into an elastic material.
2) Pre-Stressing for combination of high strength steel to high strength concrete.
3) Pre-Stressing to achieve load balancing.
Question #3: “Pre-Stress involves Pre-Compression of Concrete.” – Explain.
Ans.: During pre-stressing the concrete, which is a brittle material is transformed to elastic material by
giving Pre-Compression. This is done by compressing the concrete generally by steel under high
tension. So that the brittle concrete would be able to withstand tensile stress.
Question #4: Why Pre-Stressed concrete is made of combination with two high quality materials in a
active member?
Ans.: Pre-Stress concrete is made of combination of two high quality materials such as high strength
concrete with high strength steel in an active member, because such active combination results in a
much better behavior of two materials.
Question #5: What are the classifications of Pre-Stressed Concrete?
Ans.:
Externally or Internally Pre-stressing
Externally Pre-stressing Internally Pre-stressing
Pre-stressing concrete by adjusting its external
reaction.
Pre-stressing concrete by adjusting its internal
reaction.
Example: Arch compensating Example: Adjustment of level of supports
Linear or Circular Pre-stressing
Linear Pre-stressing Circular Pre-stressing
Linearly pre-stressed are not necessarily straight;
it could be bent or curved but it is not round.
Pre-stressing circular structure like round tanks,
silos and pipes.

of 43
Pre-tensioning or Post-tensioning
Pre-tensioning Post-tensioning
Any method of pre-stressing in which the
tendon is tensioned before the concrete is
placed.
Method of pre-stressing in which the tendon is
tensioned after the concrete has hardened.
Applicable where permanent beds are provided
for such tensioning
Applicable to members either precast or cast in
place.
End-Anchored or Non- End-Anchored Tendons
End-Anchored Non- End-Anchored
In post-tensioning tendons are anchored at their
ends by means of mechanical devices to transmit
pre-stress to the concrete. Such a member is
termed as end anchored.
In pre-tensioning tendons have their pre-stress
transmitted to the concrete by their bond action
near the ends.
Bonded or Unbonded Tendons
Bonded Tendons Unbonded Tendons
Bonded Tendons denotes those bonded
throughout their length to the surrounding
concrete
Unbonded Tendons are greased and wrapped
with paper or plastic material to prevent
bonding to the surrounding concrete.
Non- End-Anchored Tendons are necessarily
Bonded Tendons
Bonded Tendons may be purposely Unbonded
along certain portion of its length.
Question #6: What are the stages of loading system to pre-Stressed Concrete?
Ans.: There are three stages of loading:
1) Initial Stage: The member on structure is under pre-Stress but is not subjected to only super
impose external load.
2) Intermediate Stage: This is the stage during transportation & erection. This occurs only for pre-
cast members when they are transported to the site and erected in position.
3) Final Stage: This is the when the actual working loads come on the structure. The upcoming actual
working loads are as follows:
- Sustain Loads.
- Working Loads.
- Cracking Loads.
- Ultimate Loads.

of 43
Question #7: What are the advantages of Pre-Stressed Concrete?
Ans.: The advantages of pre-stressed concrete are:
i) High load carrying capacity.
ii) Pre-tested structure.
iii) Tension free.
iv) Less deflection.
v) Relatively economical.
vi) Crackless structure.
vii) Lighter weight.
viii) Allow more slender section.
Question #8: “Pre-Stressed Concrete is Pre-tested or Pre-Certified Concrete”. – Explain.
Ans.: In producing pre-stressed concrete structures, both pre-tensioning & post-tensioning – the design
is based on calculated expected load which are factored to safety. During the pre-stress operation the
steel is subjected to a high tensile stress and when the pre-stress is transformed to the concrete, the
concrete is subjected to a high compressive stress. So, in one sense, the concrete and steel are subjected
to high stresses even before application of any load.
Question #9: Why Mild steel is not used in Pre-Stressed Concrete?
Ans.: In pre-stressed concrete, high strength concrete is required to match with high strength steel in
order to yield economical portion, so that Mild steel cannot be used in pre-stressed concrete.
Question #10: “If pre-stressed concrete cracks, it behaves like a Reinforced Concrete” – Explain.
Ans.: In pre-stress concrete beam. The capacity of the concrete to carry tensile stress gets destroyed as
the cracks are develops which is objectionable for any pre-stressed structure where cracking may
results in excessive deflection. Hence it can be said that after cracking the pre-stressed concrete beam
behaves essentially as an ordinary reinforcement concrete.
Question #11: “Deflection is small in case of pre-stressed concrete.” – Explains.
Ans.: When pre-stress is transferred to concrete, compression develops with the concrete as a result of
which upward deflection occurs. When the structure is subjected to working loads, the loads cause the
upward deflection to decrease and eventually become straight. If the structure is subjected to more
extra loads, then it starts deflecting downward. So, it can be said that pre-stressed concrete is much
stronger and more capable of resisting loads and hence the deflection is small.
Question #12: Write short note on pre-stressing technique of concrete.
Ans.: Pre-stressed concrete is one kind of form of reinforced concrete. Pre-stressing techniques builds in
compressive stresses during construction to oppose. This can greatly reduce the weight of beam & slab
also by better distributing the stress in the structure to make the optional use of reinforcement in the
construction.

of 43
Question #13: “Pre-Stressed concrete plays a vital role in modern construction technology”. – Explain.
Ans.: Pre-stressed concrete is made of combination of two high quality materials such as high strength
of concrete with high strength steel in an active member, because such active combination results in a
much better behavior of the two materials which helps the concrete to play an vital role in modern
construction technology.
Question #14: Why pre-stressed concrete can be used as long span structure?
Ans.: In case of long span structure, the main obstacle is the moment, which forms from the self-weight,
super imposed dead load and live load. As the pre-stressed concrete structure is much more strong to
resist load and more slender with less cross section area resulting less amount of dead load. For these
reason the long span structure are effectively and economically build using pre-stressed concrete.
Question #15: Compare the shear carrying capacity between pre-stressed concrete beam and RCC beam.
Ans.: The use of curbed tendon in pre-stressed structure helps to carry some of the shear in a member.
In addition, pre-compression in the concrete tends to reduce the principal tension, increasing shear
strength. Thus for some external loading, every things else being equal, the shear force in pre-stressed
concrete is smaller than RCC. So, it is possible to use section in pre-stressed concrete to carry amount of
external load in a beam. There is also a definite saving in stirrups. These reduce weight will make the
member more economic for any construction.
Question #16: What is self – Stressing Cement?
Ans.: A type of cement that expands chemically after setting and during hardening are known as
expansive or self-stressing cement. When this cement are used to make concrete with embedded stel,
the steel is elongated by the expansion of the concrete. Thus the steel is pre-stressed in tension, which
produces compressive pre-stress in the concrete, resulting in what is known as chemical pre-stressing
or self-stressed concrete.
Question #17: Describe different method / system of prestressed concrete.
Ans.: There are three methods of pre-stressing cement of concrete. These are:
1. Mechanical Prestressing: In this method the prestressing is done by means of jacks. In the both
pre-tensioning & post tensioning the most common method for stressing is jacking. In pre-
tensioning jacks pull the steel with the reaction against held bulk heads or molds. In post-
tensioning jacks are used to pull the steel with reaction acting against the hardened concrete.
2. Electrical Prestressing: In this method prestressing is done by use of electricity and jacks
together. Steel is lengthened and heated by electricity. Electrical method is a post tensioning
method where the concrete is allowed to harden fully before the application of prestress.
3. Chemical Method: In this method the prestressing is done by means of expanding cement. Types
of cement that expand chemically after setting during hardening are known as self stressing
cement. When this cement is used to embedded concrete with steel, the steel is elongated by the
expansion of the concrete. Thus the steel is prestressed in tension which is known as chemical
prestressing.

of 43
Question #18: Significance of loss in Prestress.
Ans.: The total analysis and design of a prestressed concrete tendon at each significant stages of
loading, gather with appropriate material properties for that one in the life history of the structure. The
most common stages are :
- Immediately following transfer of prestress force to the concrete section stresses are evaluated
from a measure of behavior.
- At service load after all losses of prestress have occurred and a long-term effective prestress
level has been reached, stresses are checked again as a measure of behavior and sometimes of
strength.
Question #19: What are the types of loss in prestress concrete?
Ans.: The types of losses are:
(i) Elastic Shortening of concrete
(ii) Loss due to creep of concrete
(iii) Loss due to shrinkage of concrete
(iv) Loss due to steel relaxation
(v) Loss due to anchorage take-up
(vi) Loss or gain due to bending of member
(vii) Frictional Loss
(viii) Loss due to bending moment of the member.
Question #20: What are the differences between Pre-Stressed Concrete & Reinforcement Concrete?
Ans.: Differences between Pre-Stressed Concrete & Reinforced Concrete are as follows:
Sl. No. Topic Pre-Stressed Concrete Reinforced Concrete
01 · Steel & Concrete used High strength steel with high
strength concrete.
Mild steel concrete
02 · Anchoring Used Not Used
03 · Load Bearing Capacity High Comparatively low
04 · Deflection Less More
05 · Economy Economic than RCC Expensive
06 · Shock resisting ability High Low
07 · For long span Applicable Not Applicable
08 · Self weight Much less than RCC Greater than Pre-Stressed
concrete
09 · Maintenance cost High Low
10 · Manpower needed Skilled manpower Not much skilled manpower

Ad exam

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Ad exam

Similar to Ad exam (20)

More from Prionath Roy

More from Prionath Roy (20)

Ad exam