Module 1-.pdf

KTUQBANK.COM

KTUQBANK.COM

1. General Introduction to Civil Engineering Engineering is the oldest profession in the technical field and Civil Engineering is the oldest branch of Engineering. Civil engineering deals with the planning, design, construction and maintenance of buildings, roads, railways, airports, seaports, dams, canals, bridges, water supply and sewerage systems. Though in olden times, there was no formal education in the engineering field, construction of various structures like pyramids of Egypt, Taj Mahal of India, Tower of Pisa. Italy were carried out by the local artisans with their traditional knowledge and experience. The well designed towns of Mohanjo Daro and Harappa were built with properly planned and designed roads and sanitary networks around 2600 BC.

. It is reported that our ancestors lived in caves and tree tops. Later on they shifted to huts made of twigs and leaves. In the modern world, it has been recognized that it is the state’s responsibility to provide its citizens the basic amenities like food, shelter (house) and clothing. Civil Engineering has many branches like – Structural Engineering, Geotechnical Engineering, Transportation Engineering, Water resources Engineering, Environmental Engineering, Earthquake Engineering etc. Geotechnical Engineering: This subject deals with soils, rock and foundations of all structures like buildings, roads, railways, dams, tunnels etc. Before starting any work, soil samples are required to be collected from the field, brought to the laboratory and tested to find out the properties of the soils. The foundations are then designed taking into account the load of the structure. Structural Engineering: This discipline deals with the design of different structures. The structure should be safe and should be able to give the service for which it was intended. The load acting on the structure has to be identified and the stresses are to be calculated. The design should be economical also. The loads are dead load, live load, wind load and seismic load. Transportation Engineering: Transportation engineering deals with the construction and maintenance of roads, railways, airways, seaways. For the transportation of men and material a good transportation net work is very essential. This forms one of the essential requirement of the infrastructure development of the country. As far as the roads are connected they connect small villages to the major cities and industrial towns and railways help in trans[porting passengers and goods in large quantities more effectively.. Environmental Engineering: This deals with water supply and sanitary engineering. Water is an essential item for drinking, irrigation, sanitation, hydropower generation etc. The waste

7

KTUQBANK.COM

accumulated both in solid and liquid form has to be collected, treated and disposed off so that the environment is neat and clean. The atmosphere is now a days polluted due to large scale vehicles on the road, major industries and over population. Necessary steps are to be taken to reduce the effect of pollution. Water Resources Engineering: This discipline of civil engineering deals with the management of quantity and quality of water in the underground and above ground water resources, like rivers, lakes ponds and streams. The availability of water from these sources are to be analysed and actual use planned accordingly. Water as told earlier is required for irrigation, industries, drinking and transportation. Earth Quake Engineering: Earth quakes are certain tremors from the inside of earth which may create the destruction and loss of property and people.. Of course the loss depends on the intensity of earth quake. As such a civil engineer has to design a structure taking into account this seismic load. This will depend upon the actual location of the place. India has been divided into different zones according to the likely severity of the quake. It is not able to predict in advance when and where the quake may happen. The main objectives of earthquake engineering are: *Foresee the potential consequences of strong earthquakes on civil structures *Design, construct and maintain structures to reduce the after effects of earthquakes Construction Engineering: This branch of civil engineering deals with the construction of various structures like buildings, dams, water supply schemes, roads, railways, air ports, sea ports etc. First detailed engineering survey has to be made. Then design the structure and carry out the construction. Proper quality control has to be made by the site engineer so that the structure will be safe and also it should be economical. The work should be completed within the target dates as to avoid cost escalation. So many software packages are available now a days for design, drawing and project planning. Hydraulic engineering: This branch of civil engineering deals with the flow and conveyance of fluids, mainly water and sewage. The knowledge on this subject is required for the design of bridges, dams, channels, canals, water supply and sanitary engineering. Hydraulic engineering is the application of fluid mechanics principles to problems dealing with the collection, storage, control, transport of water and sewage. The hydraulic engineer has to study the effect of scour on bridges and other structures.

Surveying: Before starting a new project a survey has to be made with respect to its alignment, level, feature on the way and surroundings. The project can be a road, railway, airport, dam or other structure.. Surveying is the art of determining the relative position of points on the surface of earth with respect to its direction, magnitude and level. There are different surveys depending on the type of instruments used, purpose of survey etc. The main instruments in this connection are – chain, leveling instrument, theodolite, tachometer, total station etc. After the survey, plans are to be prepared.

8

KTUQBANK.COM

2. History of Civil Engineering It is very difficult to specify the history of the beginning of civil engineering. Our ancestors ate fruits, drank water from streams and slept in caves or on top of trees. Then they felt the need of a house for protection from rain and other atmospheric effects. They cut the trees and using the logs constructed small huts. The construction of Pyramids in Egypt (2700 - 2500 BC) is considered to be the first major civil construction. Ancient historic civil engineering constructions include the Great Wall of China (312 BC), Irrigation projects in China (around 220 BC); Julius Caesar's Bridge over the Rhine River( 55 BC), Taj Mahal (Agra), Red Fort (Delhi), Golden Temple (Amritsar), Hawa Mahal (Jaipur), Ellora Caves( Nasik), Guruvayoor Srikrishna Temple (Kerala), Maha Budha Temple (Gaya), Malankara Orthodox Church (Kerala) in India.

Great wall of China (312 BC)

Pyramids of Egypt (2700-2500 BC)

Tajmahal of india (1632) In the earliest period, the construction of structures were done using mud, stone and lime mortar. Though there was no formal education, they could design and construct such magnificent structure which are still in existence without any serious deterioration. 9

KTUQBANK.COM

One of the most essential requirements of human beings is food. For raising food crops, irrigation is required. History of Irrigation Development in World Archaeological investigation has identified evidence of irrigation in Mesopotamia and Egypt as far back as the 6th millennium BCE, where barley was grown in areas where the natural rainfall was insufficient to support such a crop. In the 'Zana' Valley of the Andes Mountains in Peru, archaeologists found remains of three irrigation canals dated from the 4th millennium BCE, the 3rd millennium BCE and the 9th century CE. These canals are the earliest record of irrigation in the New World. The Indus Valley Civilization in Pakistan and North India (from 2600 BCE) also had an early canal irrigation system. Large scale agriculture was practiced and an extensive network of canals was used for the purpose of irrigation.

Drawing water from well using bullocks Engineering Education The first engineering school, The National School of Bridges and Highways, France, was opened in 1747. In 1818, world’s first engineering society, the Institution of Civil Engineers was founded in London. The institution received a Royal Charter in 1828, formally recognizing civil engineering as a profession. Its charter defined civil engineering as: “Civil engineering is the application of physical and scientific principles, and its history is intricately linked to advances in understanding of physics and mathematics throughout history. Because civil engineering is a wide ranging profession, including several separate specialized sub-disciplines, its history is linked to knowledge of structures, material science, geography, geology, soil, hydrology, environment, mechanics and other fields.” The first private college to teach Civil Engineering in the United States was Norwich University founded in 1819. The first degree in Civil Engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835. In India, engineering education started with the opening of School of Survey in 1794, which became the Civil Engineering School in 1858 and was rechristened as College of Engineering in 1859 in Chennai (Madras). The Thomason College of Civil Engineering, Roorkee,(Uttar Pradesh) was started in 1847.whicht was given university status in 1949 and was converted to Indian Institute of Technology (IIT) in 2001.

10

KTUQBANK.COM

3. Relevance of Civil Engineering in the Infrastructure Development of the Country

Civil Engineers have a major role to play in the development of a nation as they have to make the necessary infrastructure in terms of buildings, transportation net work, dams, irrigation canals, power generating stations etc. Infrastructure can be defined as the physical and organizational structures and facilities like buildings, roads etc. needed for the operation of a society. They are required for the economic development of the country. Civil Engineering has got various branches like Geotechnical Engineering, Structural Engineering, Transportation Engineering, Environmental Engineering, Surveying - each discipline dealing with a particular aspect. In general, the functions of a Civil Engineer are Planning, Design, Construction and Maintenance of different Civil Engineering structures. The infrastructure requirements can be broadly grouped under the following categories: Buildings, Roads, Railways, Bridges, Airports, Dams and Canals, Electric Power Stations, Factories, Industrial Town ships

Buildings are required for dwelling, schools, industries, offices, hospitals, factories etc.

11

KTUQBANK.COM

Bridges are required for crossing rivers and other obstacles for both rail and road network.

Food is an essential item for all - rich and poor. Agricultural fields are to be raised and maintained properly.

For raising food production irrigation is to be effective. For this dams are required. The stored water can be used for drinking and hydroelectric power in addition to irrigation.

For transporting men and material from one end of the country to the other end railways are a must.

12

KTUQBANK.COM

For linking villages to towns, cities and industrial towns roads are required

For faster and quicker transport of passengers and goods air transport is the only solution.

Electric power is required for almost are operations – domestic, commercial or industrial purposes. The power is generated though hydro electric, thermal or nuclear power stations.

One of the parameter to measure the progress of a country is its industrial production. This can be the in the small scale sector or large scale sector. Conventional building materials like stone, brick, timber etc are still in vogue, but two materials which have completely revolutionized the construction industry are cement and steel. From a 13

KTUQBANK.COM

small one room house to a multi- storey buildings, dams, power houses, air ports, rail sleepers, concrete roads, tunnels, bridges etc all are being constructed with concrete and steel. Computers are now extensively used for design, drawing and planning of various civil engineering works. Also micro controllers are being used in various machineries used in construction activities. In the present day world “going green” is on top priority in our society. Reusing materials from existing sites is an upcoming trend in the new environment. Engineers play a very critical role in planning, developing, building and maintaining nation’s infrastructure. Ultimately, the engineering profession uses its expertise, experience and knowledge help to create a safer, more sustainable, and prosperous future for the country. Engineers balance social, environmental and economic considerations to find the best solutions to complex challenges. They have a responsibility to manage the risks associated with their work, and the impacts on the public and on the environment. The progress made by the nation in the successive five year plans is an eye-opener. The progress can be seen in all spectrum - Irrigation, Agriculture, Hydro electric power, Roads, Railways, Air ports, Sea ports, Techno / I T parks, Communication network, Cement, Steel and other heavy and light Industries. Some recent remarkable infrastructure developments in India For any country, its infrastructure is a matter of pride. During the last few years phenomenal change has taken place in sectors like buildings, roads, railways, airports etc leading to world class facilities in various parts of the country. Few such projects are briefly described here. 1. Mumbai’s Eastern Freeway – India’s second largest Fly over - More than 25000 vehicles are expected to take the freeway daily. The 17 km freeway is divided in three parts- 9.29 km elevated road, 4.3 km road-tunnel, and an elevated 2.5 km fly over.

2. Udhampur-Katra rail link (Kashmir) – The work on this line is complete. Pilgrims to Vaishnodevi temple can travel directly to the base camp at Katra. Constructed at an estimated cost of Rs 1050 crores, the route consists of seven tunnels, 30 small and big bridges.

14

KTUQBANK.COM

3. Indore’s BRTS road route- Built at a cost of Rs135 crores, the BRTS consists of physically separated bus lanes and metro like stations.

4. Double decker train from Chennai to Banglore – The fully air- conditioned train started its run on April 25, 2013.

5. India’s first solar park at Caranka village in Gujarath – This is country’s first solar park. Spread across 5000 acres it has 500 MW of generation capacity of both solar and wind energy.

6. Yamuna Expressway (Greater Noida to Agra) – The 165 km long Yamuna Expressway is the longest access controlled six-lane rigid pavements in India.

15

KTUQBANK.COM

7. India’s longest rail tunnel – The 11 km tunnel across PirPanjal mountain range on the Bani hal – Quazigund railway line in Jammu Kashmir.

8. Lulu Mall. Kochi – Constructed at a cost of Rs1600 crores at Edappally, Cochi in 25 lakh square feet complex

9. India’s Life line Express (World’s first hospital train)- Established in 1991, this train has travelled the length and breadth of the country bringing the medical aid to the most farflung inaccessible areas.

16

KTUQBANK.COM

4. Types and Classification of Structures There are different types of structures like buildings, roads, railways, air ports, towers etc. A brief description of these structures is given below: Buildings

A building is a man-made structure with proper foundation, wall, roof and other building services. It may be of mud, stone or cement blocks. The building may be for various purposes – residential, commercial, industrial, educational, religious…..It may be of various sizes and shapes National Building Code of India (2005) defines a building as a structure for any purpose built of any material. The building may be of single storey or multi-storey structure. In the last few years the cost of construction has sky rocketed due to the rise in the cost of building materials as well the increased labour cost. The cost of land has also gone up considerably. Earlier the practice was to construct single storey or two storey buildings. But the trend has completely changed due to the paucity and high cost of land and the increased demand for houses. The old system of combined family has disappeared and the trend is for miniature families. So now multistory residential complexes are being constructed. One factor which has to be taken into connection in this regard

is the Floor Area Index (FAI).

FAI = Covered area of all floors X 100

Plot Area Along with residential buildings. more buildings are required for industries, government offices, private business establishments, educational institutions etc. One important factor is the economy of construction. The space has to be effectively utilized. Green buildings are the requirement of the day. Modern construction techniques and selection of good building materials also will affect in reducing the cost of construction. Towers A tower is a tall structure. There are different towers like clock tower, transmission tower, bell tower, radio tower, communication tower etc. They are not intended for living .but for specific purposes like:

17

KTUQBANK.COM

Eiffel Tower Electricity transmission tower- for distribution of electric power Communication tower- for transmission of communication signals like microwave Radio tower - for transmission of radio signals Bell tower – for hanging bells in churches Tourist tower – As a tourist attraction for the tourists to see (Eiffel tower in Paris, Leaning tower of Pisa, Italy etc)

The towers are normally constructed with steel sections like angle, I section, Channel, square section etc and are connected at the junctions through welding or bolt and nut.

Chimneys

A chimney (flue) is a structure intended for the passing off smoke, hot flue gases

from furnace or fireplace to the outside atmosphere. Chimneys are kept in vertical position so that the gases pass smoothly. Chimneys can be found in buildings, steam locomotives, ships, brick kilns, factories etc.. Since in factories the pollutant gases are passed out through tall towers, the surrounding area is not polluted. In addition, the dispersion of pollutants at higher altitudes can reduce their impact on the immediate surroundings. The cross section of a chimney may be square, rectangular or circular with smooth finish inside. The height of the chimney stack should be at least one meter above the roof level. In big factories, tall chimneys are provided to pass the exhaust gases and smoke at a higher level. The following points must be kept in mind while constructing a tall chimney-

18

KTUQBANK.COM

-Refractory brick lining should be provided inside a chimney when the temperature is expected to exceed 750 degree centigrade. -The total height of the chimney shaft should not exceed 12 times the external diameter at the base or 10 times the least lateral dimension at the base for chimneys of rectangular section. The general practice is to construct the chimneys in lime mortar than cement mortar because cement mortar is likely to disintegrate at high temperature. - Wind pressure must be taken into account when designing a chimney.

Bridges

A bridge is a structure built to cross an obstacle. The obstacle may be a river, railway line, road or canal. Classification Bridges are classified in different ways according to: Material of construction - Timber, Masonry, Steel, RCC, PSC. Purpose (Function) - Railway bridge, Road bridge, Pedestrian bridge, Aqueduct (bridge over a valley), Viaduct (canal over a river) Position - Deck bridge, Through bridge, Semi through bridge Superstructure - Slab bridge, Truss bridge, Suspension bridge, Cable stayed bridge Length - Culvert (less than 6 m, Minor bridge (6 to 60 m), Major bridge (above 60 m) Method of connection of different parts- Rivet, weld, Pin Position - Straight, Skew Selection of site The following points are to be considered in selecting the site of the bridge – The site should be easily approachable, Width of the river should be minimum, Firm and stable banks, Suitable foundation, Right angled crossing The components of a bridge are Abutments, Pier, Deck Slab, Hand- rail, Beam, Bearings, Approaches, Parapet

19

KTUQBANK.COM

Dams Dams are structures constructed across rivers to store water. The water may be used for drinking, irrigation or hydro electric power generation.

There are different types of dams – Based on functionStorage dam – This is constructed to store water. The stored water may be used for irrigation, drinking or hydro electric power generation. Flood control dam – This is temporarily constructed to store the flood water and release it slowly so that the down- stream side is safeguarded against the damaging effects of floods. Diversion dam - This is constructed to divert the water from the river to a channel. Coffer dam – A temporary structure constructed to divert water so that the new dam or bridge can be constructed. Based on material of construction – Earthen dam , Masonry dam , Concrete dam

20

KTUQBANK.COM

Retaining Walls

Retaining walls are walls made of concrete or masonry to retain soil. Generally they are constructed on the approaches to bridges, for making gardens in sloping grounds and to protect soil from erosion etc. To design a retaining wall, it is required to find out the pressure exerted by the soil on the retaining wall. This can be found out by using Rankin’s theory or Coulomb’s theory. The pressure depends on the unit weight of soil, angle of internal friction, cohesive strength of soil and height of the wall. There is a tendency for the retained material to move down the slope due to gravity. This creates lateral earth pressure behind the wall which is termed as active earth pressure. If the retaining wall yields towards the retained soil. the wall is subjected to passive earth pressure. If there is no movement, the earth pressure is called earth pressure at rest.

Water tanks

A water tank is a container to store and distribute water. The water may be used for drinking ,irrigation or fire suppression. It can be at the ground level or on an elevated stage. They may be of steel, concrete or plastics and of circular or rectangular in shape. Now a days for rain water harvesting also tanks are being used. Rainwater tank (sometimes called a rain barrel ) is a water tank used to collect and store rain water runoff from roof tops via rain gutters. A rainwater catchment or collection (also known as "rainwater harvesting") system can yield 2358 litres of water from 2.54 cm of rain on a 93 m 2 roof area. Rainwater tanks are devices for collecting and maintaining harvested rain. These tanks are installed to use rain water for later use. and aid selfsufficiency. Stored water may be used for watering gardens, agriculture, flushing toilets, in washing machines, washing cars, and also for drinking, especially when other water supplies are unavailable.

21

KTUQBANK.COM

Underground rainwater tanks can also be used for retention of storm water for release at a later time.

Silos

Silo is a structure, typically cylindrical in shape in which grain, cement or other materials are stored. There are different types of silos such as the low-level mobile silo and the static upright silo. Mobile silos are normally of capacities from 10 to 75 tons. They are simple to transport and are easy to be set up on site. These mobile silos generally come equipped with an electronic weighing system with digital display and printer. This allows any quantity of cement or powder discharged from the silo to be controlled and also provides an accurate indication of what remains inside the silo. The static upright silos (Tower silos) have capacities from 20 to 80 tons. They are also cylindrical in shape, 4 to 30 m in diameter and 10 to 84 m in height. The stored materials are unloaded into wagons, trucks or conveyors. Silos can be of steel or concrete. The main differences between concrete and steel silos are: 

All steel silo parts are manufactured in a factory, so the quality can be totally controlled, whereas cast in place concrete silos involve more variables such as delivery of concrete and weather.



The slip frame concrete process is slightly complicated. Also, field supervision plays a really important role in concrete silos: More workers have to be employed and also it takes more time for construction. Ultimately the cost of construction shoots up. Concrete silos can be taller than steel silos.

   

It is easier to erect steel silos and also to install accessories like doors, ladders, samplers, etc. Steel structure is more flexible, so steel silos have better behavior in case of earthquake.



Regarding air tightness, both structures are normally airtight if the openings are properly sealed. Steel silos generally give more storage capacity.. They tend to be more cost-effective because of the higher storage capacity.



It is easier and more effective to do aeration in steel silos.

22

KTUQBANK.COM

Roads

Roads are for the transport of men and material from one part of the country to another part. In India, roads are classified under the following categories - National High way, State Highway, Major District Road, Other District Road and Village Road. There is now a new classification as Express Way. The road structure has the following components – Sub grade, Sub base, Base, Base Coat and Wearing Coat.

Typical X section of a flexible pavement Before upgrading and widening an existing highway, a traffic survey is to be conducted to collect information about the traffic density, direction of movement of vehicles, origin – destination of vehicles, type of vehicles, type of soil, geographic details including anticipated future development. AS far as the geometry of roads are concerned, on curves the outer portion is slightly rais with respect to the inner side. This is known as cant (super elevation). This is provided to counteract the centrifugal force of the vehicle. This will depend on the degree of curvature and speed of vehicle. Also to drain out rain water, side slopes are to be given to the wearing surface.

23

KTUQBANK.COM

Runways

A runway is a rectangular area of land in an airport prepared for the landing and takeoff of aircraft. Runways may be a man-made surface (asphalt, concrete, or a mixture of both) or a natural surface. It is generally paved. Shoulders are provided on either side of a run way. They act as safety zones should an airport move out of the runway during take off or landing. Stop ways are provided at the ends of a run way to accommodate an aircraft that overshoots or undershoots a run way during landing or an aborted take-off. Runways are named by a number between 01 and 36, which is generally the magnetic azimuth of the runway's heading in deca degrees: A runway numbered 09 points east (90°), runway 18 is south (180°), runway 27 points west (270°) and runway 36 points to the north (360° rather than 0°). Air ports are of two types: Civil airports, Military airports The selection of a site for an airport depends on – Economic factors, Commercial factors, Meteorological factors, Physical and Engineering factors.

Typical Layout of Air port

24

KTUQBANK.COM

The capacity of an airport is defined as the number of aircraft operations during a specified interval of time corresponding to a tolerable level of delay. The factors that affect the capacity of an airport are: -The number of runways and whether they are used for both arrivals and take-offs or separately for arrivals and take-offs. - Orientation and configuration of runways -The taxiway -The efficiency of traffic control facilities -Weather conditions A single runway used both for arrival and departure can have an annual capacity of 170,000 to 215,000 air craft operations. In an emergency, military aircrafts may land on Express Highways. Recently this facility was tested by landing and taking off a military aircraft on Delhi Agra Express Highway.

Railways

Railways are the life lines of a nation. For transporting men and material railway net work is very essential. It was in 1853 that the first train started its maiden journey from Bombay to Thana a distance of 15 Kms. Now Indian railways have got 65000 route Kms of track, carrying about 23 million passengers per day by 19000 trains connecting about 8000 stations.. It also runs about 7,000 freight trains carrying about 3 million tonnes of freight every day. It is the largest Government department and is the only department which has got a separate annual budget. Trains run over two rails which are kept at a specific distance .on a transverse member called sleeper. The distance between the two rails is called gauge which is 1676 mm for Broad gauge and 1000 mm for Metre gauge track. Below the rails, there is a layer of broken stones (ballast) of about 20 cm. Previously the sleepers were of wood, steel or cast iron. But now concrete sleepers are being used. Similarly earlier the trains were hauled by steam locomotives but now the same are hauled by diesel or electric locomotives. 25

KTUQBANK.COM

The railway is administered by the Railway Board composed of Chairman and four other Members. The whole rail network is divided into different zones which are headed by a General Manager. The zone is further subdivided to Divisions. and Sub divisions. For design, development and standardization of railways there is a separate organization under the Ministry of Railways called Research Designs and Standards Organisation (RDSO) based at Lucknow. Pipelines

Pipeline transport is the transportation of goods through a pipe. As per statistics of 2014, total of about 3.5 million km of pipeline is there in 120 countries of the world. The United States has 65%, Russia 8%, and Canada 3%, thus 75% of all pipe line is in these three countries Liquids and gases are transported through pipelines. Pipelines exist for the transport of crude and refined petroleum, fuels - such as oil, natural gas and bio fuels - and other fluids including sewage, slurry and water. Pipelines are useful for transporting water for drinking or irrigation over long distances. Pneumatic tubes using compressed air can be used to transport solid capsules. Oil pipelines are made from steel or plastic tubes which are usually buried underground. The oil is moved through the pipelines by pumping from stations along the pipeline. Natural gas (and similar gaseous fuels) are lightly pressurised into liquids known as Natural Gas Liquids (NGLs). Natural gas pipelines are constructed of carbon steel. Highly toxic ammonia is theoretically the most dangerous substance to be transported through long-distance pipelines. Hydrogen pipeline transport is the transportation of hydrogen through a pipe. Pipelines conveying flammable or explosive material, such as natural gas or oil, pose special safety concerns and there have been various accidents. Pipelines can be the target of vandalism, sabotage, or even terrorist attacks. In war, pipelines are often the target of military attacks. Advantages of transport through pipes:   

Large-scale transportation of natural gas by tanker truck or rail is not feasible Pipelines are a safe and efficient means of transporting large quantities of crude oil and natural gas over land. Pipelines are more cost-effective than the alternative transportation options

26

KTUQBANK.COM

 

They require significantly less energy to operate than operating trucks or rail and have a much lower carbon footprint Underground pipelines are safe

Points To Ponder

    

   

A building is a structure with foundation, walls and roof covering. It is used for dwelling, office, factory, business establishment and other purposes. The size and shape of the building depend on the purpose of the same. Even though there was no formal education, artisans in olden days were able to construct buildings using locally available materials. Some of the structures constructed long back and are still in existence are – The Great Wall of China, Pyramids of Egypt, Leaning tower of Pisa, Tajmahal at Agra, Redfort at Delhi etc. In addition to buildings, there are many other structural elements which are in use like – Chimneys, Towers, Water tanks, Roads, Railways, Airports, Pipe lines etc. Civil engineers have a major role to play in the infrastructure development of the country. For a nation’s development houses, factories, roads, railways, airports, dams, power generating stations etc are required. It is the duty of Civil Engineers to plan, design, construct and maintain these structures.

Model Questions 1.Biefly describe the history of Civil Engineering. 2 What is a building? 3. What is the purpose of a building? 4. What is the role of a civil engineer in the nation building? 5. Briefly explain the following items – Water tanks, Chimneys, Retaining Walls, Silos, Runways, Dams, Towers 6.Explin some of the recent systems in operation as part of India’s infrastructure development.

27

KTUQBANK.COM

5. Definition and Types of Buildings as per National Building Code of India The National Building Code of India (NBC) is a comprehensive building Code. It is a national instrument providing guidelines for regulating the building construction activities across the country. It serves as a Model Code for adoption by all agencies involved in building construction works - the Public Works Departments, other government construction departments, local bodies or private construction agencies. The Code mainly contains administrative regulations, development control rules and general building requirements; stipulations regarding materials, structural design and construction (including safety); and building and plumbing services. Buildings may be classified according to various parameters like occupancy, load transfer, materials used and fire resistance. The National Building Code of India (Part iii 2005) classifies buildings as per occupancy in the following nine groups: Classification of buildings as per occupancyGroup A – Residential Group B - Educational Group C - Institutional Group D - Assembly Group E - Business Group F - Mercantile Group G - Industrial Group H - Storage Group I – Hazardous Group A – Residential Buildings – These are the buildings in which sleeping accommodation is provided for normal residential purposes with or without cooking or dining or both facilities except any building classified under Group C. Group A buildings are further classified as A1 to A5. A1 – Lodging Houses - These are buildings in which under the same management , separate sleeping accommodation for a total of not more than 40 persons on transient or permanent basis with or without dining facilities but without cooking facilities for individuals is provided. A2 – One or two private dwelling houses – These are occupied by members of a single family and have a total sleeping accommodation for not more than 20 persons.

28

KTUQBANK.COM

A3 – Dormitories – These are buildings in which group sleeping accommodation is provided with or without dining facilities for persons who are not members of the same family in a room or a series of closely associated rooms under joint occupancy and single management. Examples – hostels, military barracks A4 – Apartment houses (Flats) –These are buildings under single management in which living quarters are provided for three or more families. A5- Hotels –These are buildings under single management in which sleeping accommodation is provided for hire to more than fifteen persons. Group B: Educational Buildings The buildings used for schools, colleges, or other training institutions that involve assembly during the day for instruction, education are considered educational buildings. Sub divisions B1 – Schools up to senior secondary level with not less than 20 students. B2 – All other training schools with less than 100 students Group C: Institutional Buildings A building or part of a building that is used for the purposes such as medical or other treatment or care of persons suffering from physical or mental illness, disease or infirmity; care of infants, or aged persons in which the liberty of inmates is restricted are categorized as institutional buildings. They normally provide sleeping accommodation for the occupant. They are further sub - divided as: A6 - Hotels (starred) C1- Hospitals and sanatoria C2 – Custodial Institution C3- Penal and mental institutions Group D: Assembly Buildings These shall include any building or part there of where a group of not less than 50 people gather for amusement, recreation, social, religious and for similar purposes. Ex- Cinema halls, theatres, exhibition halls, museums, restaurants etc. These buildings are further sub divided into – D-1: Buildings having stages and fixed seats more than 1000. D-2: Buildings having stages and fixed seats less than 1000

29

KTUQBANK.COM

D-3: Buildings without stages and accommodation for 300 or more persons but no permanent seating arrangements D-4: Buildings without stages and accommodation for less than 300 persons. D-5: All other structures for assembly of people not covered by sub divisions D-1 to D-4. ExCircus tents D-6: Buildings having mixed occupancy providing facilities such as shopping, restaurants etc. D-7: All other buildings for assembly of people not covered under D-1 to D-6 Group E: Business Buildings This group includes any building or part of a building that is used as a shop, store either whole sale or retail. These are sub divided into E1 – E5: Mercantile Buildings F1: Shops, stores markets area upto 50sq m F2: Underground shopping centres, departmental stores with area more than 500 sq m Group G: Industrial Buildings These include buildings or part thereof in which materials of all kinds are manufactured or processed G1- Buildings used for low-hazard Industries: These are buildings where danger to life and property may arise from panic or fire from external sources only. G2- Buildings used for moderate-hazard Industries: The processes in the industries are liable to give rise to a fire that will burn with moderate rapidity. G3- Buildings used for high-hazard Industries; The processes in the industries are liable to give rise to a fire that will burn with extreme rapidity. Group H: Storage Buildings These are buildings used for the storage of goods, vehicles or animals. Group J: Hazardous Buildings These are buildings used for storage, handling, manufacturing of highly explosive materials or products which are liable to burn with extreme rapidity producing poisonous gases or explosions.

30

KTUQBANK.COM

Classification of buildings according to the type of construction: Classification according to method of load transfer Types of structures: Load-bearing structure: The load of roof and floors is transferred to the foundation by thick walls. Framed structure: The load of roof and floors is transferred to the foundation through columns and footings. Walls serve as partitions only. Comparison of load bearing and framed structure: Load bearing structure *Load from roof and floors are transferred to

Framed structure *Transferred through columns and footings

foundation by walls *Walls need foundation throughout

*Footings are required for columns only

*Thickness of load bearing walls should be

*Only exterior walls need 200 mm thick,

at least 200mm *Too many openings for doors, windows and

others need 100 mm thick only * No restriction

ventilators are not permitted *Suited for residential purpose - one or two

*Suitable for multi storey buildings

storey only Classification of buildings according to the materials used RCC structure, Steel Structure, Composite Structure: Classification of buildings according to fire resistance There are four categories in this regard: Type 1, Type 2, Type 3 and Type 4 construction.

31

KTUQBANK.COM

Points To Ponder

    

National building code of classifies buildings into different categories. The two categories are – buildings based on occupancy and buildings based on type of construction Based on occupancy buildings are further classified into 9 groups – A to I These nine groups are – Residential, Educational, Institutional, Assembly, Business, Mercantile, Industrial, Storage, Hazardous According to the type of construction buildings are classified into – Method of load transfer, According to the material used, According to the fire resistance

Model Questions 1. What s National Building Code? 2.What are the parameters of classification of buildings? 3.Based on occupancy what are the classifications? 4.What are the classifications of buildings according to type of construction? 5.What are the classifications of buildings according to method of load transfer? 6.What are the classifications of buildings according to material used? 7.What are the classifications of buildings according to fire resistance?

32

KTUQBANK.COM

6. Components of a Building and their functions Buildings are of different types - residential, commercial, public utility, educational, recreational etc. The type, size, nature of construction etc of the buildings may vary. Before starting the construction of the structure, a plan of the building has to be prepared. Then the approval of local authority – Panchayat, Municipality or Corporation – has to be obtained. The plan of a building has to be prepared in consonance with the building bye-laws of the state. Components of a building The basic components of a building are: Foundation, Plinth, Column, Wall, Lintel, Door, Window, Floor, Stair, Roof Foundation: The foundation is the lowermost part of a building. It is below the ground level. The purpose of a foundation is to distribute the load of the superstructure to the soil below, give stability to the building and to prevent the overturning of the building.

Plinth: It is the portion of a building between the ground level and the ground floor level. A damp proof course is provided at the top of the plinth. Column: These are vertical members which transfer the load from top to the bottom member. The column can be of timber, steel or concrete. It may be of circular, rectangular or square section. Wall: The wall is also constructed to transfer the load from top to the bottom member. It has got the further function of giving protection to the inhabitants from rain, wind etc. and also privacy.Walls partition the building into different rooms / compartments.

33

KTUQBANK.COM

Lintel: It is a small beam provided over window and door openings to transfer the load from above. It can be of wood, steel or RCC. The width of lintel will be that of the wall. Door and Window: A door is provided to get access to the room and also to lock it for safety. Window is provided in the exterior wall to have light and air circulation. The window area should be 15-20 % of the floor area. Floor: The number of floors depend on the height of the building. The lowermost floor is the ground floor. It is prepared by filling the basement with soil and then compacting it. The top is made by marble, tile or stone. The upper floors are generally of RCC. The thickness of slab wil depend upon the span and the load it is subjected to. Stair: Stair is constructed to go from one floor to the other. It will have a number of steps. A landing is normally provided in between the floors. Roof: It is the topmost part of a building. It serves as a cover for protection from rain, wind and sun rays. The roof can be flat or sloping. It should be leak proof and should give a good look to the building. Building Services: The essential building services are: water supply, sanitary fittings and connections, electric connection, rain water drainage system, cup boards, shelves etc. The details of each component of a building are being described here in :

Foundation Foundation is the lowest part of a structure. It is below the ground level. The purpose of the foundation is to transmit the load of the superstructure to the soil below so that the structure is safe. The engineer has to study the properties of the soil and design the foundation accordingly. It should be ensured that the foundation can safely carry the loads. Requirements of Foundation: -The pressure exerted on the soil should not exceed the safe bearing capacity of the soil. -Settlement of the foundation should be with in safe limit. -The foundation should be rigid.

34

KTUQBANK.COM

Types of Foundations 1. Shallow foundation 2.Deep Foundation A foundation is said to be shallow if its depth is less than or equal to its width. Shallow foundations are also called spread footings or open footings. The 'open' refers to the fact that the foundations are made by first excavating all the earth till the bottom of the footing, and then constructing the footing. There are several kinds of shallow footings: Spread footing, individual footing, combined footing , raft foundation etc. Wall footing (Spread footing): The width of the foundation is gradually increased through steps. Trenches are made to the required depth and width. Then a leveling layer of concrete is spread Over that the foundations are constructed in masonry.

Column footing: Columns normally carry heavier loads. Therefore they require footings which can distribute loads to larger areas. The footings of this type are:  Isolated column footing  Combined footing 

Cantilever or strap footing

 

Continuous footing Raft or mat footing

Isolated column footing: This footing is adopted for independent column. The size of the footing will depend on the load on the column and the type of underlying soil.

35

KTUQBANK.COM

Combined Footing: This is a common footing for two columns. This footing can be rectangular or trapezoidal in shape. This type of footing is adopted when one column is very near the boundary of a plot where there is not sufficient space for the footing.

Cantilever (strap footing) This type of combined footing is adopted when the distance between the columns is quite large .A strap beam is provided connecting the slabs under each column.

36

KTUQBANK.COM

Continuous (Strip) Footing: This type of footing is adopted when more than two columns are to be constructed in one line very close to each other..

Raft Foundation

This is also known as mat foundation. In some cases the individual columns may be heavily loaded or the safe bearing capacity of the soil may be low. In that case, the column footings may overlap each other. Raft foundation is adopted in such situations.

37

KTUQBANK.COM

Grillage foundation: In some buildings, steel columns embedded in concrete are to be constructed. The columns may have to carry heavy loads. In such situations, grillage foundation is adopted. It consists of one or more tiers of steel beams inside concrete. A base plate will be provided at the base of the column.

Deep Foundations 1..Pile foundation 2. Pier foundation Pile foundation: A pile is a slender column of wood, steel or concrete. It is driven into the ground or cast in a bore hole. Classification of Piles according to the load transfer: Friction Piles

Bearing Piles

Friction piles transfer the load through friction between the pile and soil. The length of the pile will depend on the frictional resistance. Bearing piles transfer the load through bearing on a hard strata. For this hard strata should be available at a reasonable depth. Classification of piles according to the material used: Timber piles, Steel piles, Concrete piles Bearing Capacity of Soil: It is defined as the maximum load per unit area which a soil can withstand without yielding. First the maximum bearing capacity of the soil has to be determined. There are different methods of determining the bearing capacity. The safe bearing capacity is then calculated by dividing the maximum bearing capacity by a factor of safety which is usually taken as 2 or 3.

38

KTUQBANK.COM

Determination of bearing capacity of soil 1. Field Tests 2. Laboratory tests 1. Field Tests Plate load test The arrangement for plate load test is given in the figure below. Plate load test The arrangement for plate load test is given in the figure below.

Plate load test arrangement For this test, first a pit is made at the desired depth. A test plate is kept at the centre of the pit. The load is applied in steps and the settlement noted. The pressure v s settlement is then plotted. The ultimate bearing capacity is then calculated. The safe bearing capacity is the ultimate bearing capacity divided by factor of safety.( 2 or 2.5) Standard Penetration Test (SPT) The Standard Penetration test (SPT) is an in- situ testing method to determine the engineering properties of subsurface soils. It is a simple test to estimate the relative density of soils and approximate shear strength parameters. In Standard Penetration Test (SPT) a standard thick-walled sampling tube is driven into the ground at the bottom of a borehole by blows from a slide hammer with standard weight and falling distance. The sampling tube is driven 150 mm into the ground and then the number of blows needed for the tube to penetrate each 150 mm (6 in) up to a depth of 450 mm (18 in) is recorded. The sum of the

39

KTUQBANK.COM

number of blows required for the second and third 6 in(150 mm) of penetration is reported as SPT blow value, commonly termed the "N-value". The N-value provides an indication of the relative density of the subsurface soil, and it is used to estimate the approximate shear strength properties of the soils.

Correlation between SPT (N value), friction angle, and relative density Correlation between SPT-N value and friction angle and Relative density (Meyerhoff 1956)

SPT N3 [Blows/0.3 m]

Soil packing

Relative Density [%]

Friction angle [°]

<4

Very loose

< 20

< 30

4 -10

Loose

20 - 40

30 - 35

10 - 30

Compact

40 - 60

35 - 40

30 - 50

Dense

60 - 80

40 - 45

> 50

Very Dense

> 80

> 45

2.Laboratory tests: Undisturbed soil samples are collected from the field and tests conducted in the laboratory to determine the shear strength of soil. Bearing capacity is then calculated. Presumptive Bearing Capacity National Building Code has recommended safe bearing capacity for different soils. Type of soil Fine sand, silt Medium clay Soft rock

40

Safe bearing Capacity (kN/sq m) 150 245 440

KTUQBANK.COM

Walls Walls are the vertical elements of a building. They enclose the space within it and also divide that space

Functional Requirements     

strength and stability weather resistance fire resistance thermal insulation sound insulation

The walls are usually constructed of bricks, stones or concrete blocks in cement mortar. Retaining Wall and Breast Wall Retaining wall is constructed to retain soil or other fill material. Breast wall is to prevent slippage of natural slopes .The lateral pressure on the wall is to be calculated and then the design made accordingly. Columns The vertical support which is free from all sides and transfers the load to the floor below is called a column. The column can be of wood, steel or RCC. It can be of circular, rectangular or square in section.

41

KTUQBANK.COM

Beam

Beam is a horizontal structural member supporting the floor above. The beam can be of wood, steel or RCC. Slab is constructed to divide the vertical space into various stories. The topmost slab is the roof slab.

Floors are made of concrete. Steel bars are provided to take up the tensile stresses. The diameter of the bar and the spacing of the bars will depend on the span of the room and the intensity of load.

42

KTUQBANK.COM

Lintel

Lintel is a small beam provided over window and door opening to support the masonry above. The lintel can be of wood, steel or RCC..

Arches

Arches are curved members provided over openings like door and window to support the wall above. Elements of an Arch Keystone: It is the wedge shaped block provided at the crown of an arch. Extrados: it is the outer portion of an arch. Intrados: It is the inner portion of an arch. Voussoirs: They are the wedge shaped units forming the arch. 43

KTUQBANK.COM

Clear span: It is the horizontal distance between the supports. Rise: It is the vertical distance between the highest point on the intrados and the springing line. Spring line: The imaginary line joining the springing points. Springing points: The points from which the curve of the arch starts. Stairs

A staircase or stairway is one or more flights of stairs from one floor to another. It includes landings, newel posts, handrails, balustrades and additional parts. It can be of wood, reinforced cement concrete, iron or steel. According to their form, the staircases can be with straight flights,

with swinging flights, arched flights or spiral flights. Roof The roof is the topmost part of a building. It serves as a protective cover of the building. It protects the inhabitants from rain, sun, wind and other climatic conditions. There are mainly three types of roofs - Sloping or pitched roofs - Flat or terraced roofs - Folded plate and shell roofs Door

Door

44

KTUQBANK.COM

Doors are openings in the wall at the floor level for entry and exit of persons, safety, security and for light and air. The number of doors in a room should be the bare minimum. Its position should judiciously selected. In genera doors have a frame and one or two shutters. There are different types of doors – Framed and braced door, Panelled door, Glazed door, Flush door, Revolving door, Sliding door, Folding door etc.. Window Windows are openings provided in the wall for light, air and outside view. The window has also got a frame and one or more shutters. There are different types of windows like – sliding window, louvered window, Bay window , Pivoted window. The window frame can be of timber, steel or aluminium.

Lifts Normally in an ordinary house, people go from ground floor to other floors through a stair case. But now a days more buildings are of multi stories whether residential commercial or office building. In such buildings it is very difficult to move up through a stair case. Lifts are used there for moving from one floor to another. It can be told that lLift is a moving platform which moves up and down in a small enclosed space.

Escalator Escalator is a system of movable stairs used to move people upward and downward directions. In public places like airports, railway stations, super markets etc escalators

45

KTUQBANK.COM

are installed for the convenience of general public. The speed of escalators are generally 0.75 m /second..

Points To Ponder

         

The basic components of a building are: Foundation, Plinth, Column, Wall, Lintel, Door, Window, Floor, Stair, Roof The purpose of a foundation is to distribute the load of superstructure to the soil below. There are two types of foundations – Shallow and deep foundation Spread footing, combined footing, grillage foundation etc come under shallow foundation. Pile foundation, Pier foundation and well foundation come under deep foundation. Walls provide security to the in -habitants and also protection from rain, wind and sun Columns are vertical members to transfer the load from top to bottom. Hey may of wood, steel or concrete and may be of square, rectangular or circular in section. There are different floors in a building – ground floor and upper floor. The roof is the topmost floor which provides protection to the building from rain, wind, snow etc. The roof covering may be of tiles, slates or concrete slab. Doors and windows are provided for access to the building, security for inhabitants, light and air. Model Questions 1. 2. 3. 4. 5. 6. 7. 8. 9.

46

What are the main components of a building? What is a foundation? What are the different types of foundations? What are the types of walls? What is a column? What is the purpose of a door? What is a lintel? What is a pile foundation? Explain lift and escalator.

KTUQBANK.COM

47

KTUQBANK.COM

17.Selection of the site for a building

There are many factors which must be taken in to account while selecting a site for a commercial, industrial l or a residential building. Some of these factors are given below. 1. 2. 3. 4. 5.

Purpose of the building Shape of the Plot Location of the plot Availability of amenities Water Table

A. Residential Building

1.Purpose of the building First the purpose for which the building is being constructed should be identified. If it is for residential purpose, it is ideal that the building is away from main business centre of the city. If it is for a factory, it should be near to a place where raw materials are available in the vicinity.

2. Shape of the plot: Geometry of the plot for any kind of construction is very important which can largely effect the appearance of the structure. Shape of the plot should be such that the construction can be easily made with out incurring much expenditure. And also there must be space for future expansions.

3. Location of the plot: The site should be located in a fully developed place . It is desirable that there are no major industries in the vicinity so that the environment is not polluted. The site should be slightly elevated so that there is no chance for stagnation of water. The soil at the site should be of good quality so that the bearing capacity of it is comparatively high.

122

KTUQBANK.COM

4. Availability of Amenities: Plot for a residential building should be taken in the area provided with amenities like electricity, telephone, Internet, Gas, School, Colleges, University, Hospital etc Another important facility is the good and fast transport system..

5. Availability of Water: The water should be available from wells in the vicinity or other wise it must be available through pipes provided by local government agencies.

6.Orientation of the site: Orientation of the site has some bearing on its selection. Site should be such that early morning sun and late evening sun is available in the building. 7. Good Landscape: The site should have a good landscape to promote a peaceful and serene environment. 8. Good surroundings: For a happy and comfortable living, the residents in the neighbourhod should be of almost equal status. B. Industrial Building 1. The factory site should be away from residential locality. 2. There must be space for future expansion 3. Raw materials should be available in the neighbor hoods. 4. It is preferable that the site is on an elevated plot so that the rain water will not get stagnated. 5. The site should be well connected by road, rail and air. 6. Electric power is readily available. 7. There must be facility for treatment of the effluent before discharging out. 8. Availability of local trained labour

123

KTUQBANK.COM

C. Educational Building: 1. The site should be away from the main city centre 2. The site should be well connected by road 3. The surroundings should be neat and clean with out noise pollution 4. Drinking water should be available through out the year 5. It is preferable that the building site is slightly elevated so that water will not get stagnated 6. Natural light is available 7. There must space for play ground as well as for future expansion.

124

KTUQBANK.COM

18.Setting out of a Building Plan On Ground Before starting the excavation for the foundation, the centre line and outline of excavation should be clearly marked on the ground. Procedure:

Fig.1: Example plan to be set out on the ground 1. From the plan (fig 1), the centre line of the walls are calculated. Then the centre lines of the rooms are set out by setting perpendiculars in the ratio 3:4:5. Suppose the corner points are A, B, C, D, E, F and G which are marked by pegs with nails on top. 2. The setting of the corner point is checked according to diagonals AC, BD, CF and EG. 3. During excavation, the centre points A,B,C,D,E,F,G may be removed. Therefore the centre lines are extended and the centre points are marked about 2m away from the outer edge of excavation. Thus the points A1, A2, B1, B2 and like wise, are marked outside the trench. Centre line are shown clearly by stretching thread or rope. The centre points fixed 2m away from the excavation are marked with sit out pegs.

125

KTUQBANK.COM

4. From the plan details, the width of excavation to be done is also marked by thread with pegs at appropriate positions. 5. The excavation width is then marked with lime or with furrow by spade. See the video clip for setting out a building-Part 1,2,3 https://www.youtube.com/watch?v=Lyb20DhmT90 For detailed information about setting out visit the site: http://www.tcd.ie/civileng/Staff/Brian.Caulfield/3A1/3A1%20Lecture%2011.pdf

126