ANALYSIS AND DESIGN OF MULTISTORIED SCHOOL BUILDING

ANALYSIS AND DESIGN OF MULTISTORIED SCHOOL BUILDING2015

ABSTRACT The objective of our project is to analyze and design a MULTISTORIED SCHOOL BUILDING of capacity 1300-1500 students considering gravity loads (Dead load and Live load) using STAAD-Pro.The foremost basic is to obtain the plan of the multistoried school building with ground and 3 floors (G+3). Depending upon the area of plot and demand for the size of the rooms (as per IS 8827-1978, BUILDING BYE LAWS, Primary classroom 1 to 1.4 sq.m per student, secondary classroom 1.2 to 1.5 sq.m per student, staff room 2.5 to 3 sq.m per teacher, laboratories 60 to 65 sq.m, medical inspection room 30 to 35 sq.m office room 30 to 35 sq.m verandah 2 to 2.1 sq.m Wash rooms 1.2 to 1.5 sq.m per student, width of stair case 1.5 to 2 mts. other required room dimensions are also obtained from these code books ). The columns and beams are fixed up as per structural requirement and their layouts are also prepared. There after loads are calculated namely dead load and live load using IS 875 part 1 and part 2. Once the loads are obtained, the component that takes the load first i.e. the slab (continuous slabs are preferred in multistoried buildings comprising tee beam and slab floors, the slabs are continuous over the beams which are spaced at regular intervals) is designed upon the end conditions. For designing columns, it is necessary to know the moments they are subjected to. For this purpose, frame analysis is done using STAAD-Pro.The design involves load calculations manually and analyzing the whole using STAAD-Pro. The design of structure is based on LIMIT STATE METHOD (IS 456:2000). The drawings of various structural members are prepared using AUTO-CAD.

CHAPTER 1INTRODUCTION1.1 BASIC INTRODUCTIONDuring the nineteenth century as population grew and became more urbanized , the organization of society required institutions to focus and concentrate activities for the individual and mutual benefit. These institutions required buildings to accommodate their activities and, typically, the Victorians built them with great civic pride. Consequently, the designs could achieve high standards and many institutional buildings are now listed.Educational building include any building used for school, college or day-care purposes involving assembly for instruction, education or recreation and which is not covered by assembly buildings. The object of this project is to illustrate the design of R.C.C member along with analysis of framed structure and all its components in addition to planning, estimation.

1.2 ENGINEERING STRUCTURE AND STRUCTURAL DESIGNAn engineering structure is an assembly of members or elements transferring the load or resisting external actions and providing a form to serve the desired function.The structural design is a science and art of designing with economy and elegance. A durable structure is one which can safely carry the forces and can serve the desired function satisfactorily during its expected service life plan.1.3 BASIC REQUIREMENTS OF STRUCTURAL DESIGN1. Serviceability1. Safety1. Durability1. Economy

Stages in structural planningOnce the type of structure is finalized and planned, design of structure involves the corresponding stages in the planning.1. Column positioning1. Orientation of columns1. Beam location1. Spanning of slabs1. Layout and planning of stairs1. Type of footingThe preliminary terms commonly used in the planning techniques and methods of building construction are introduced:BuildingBuilding is defined as any structure for whatsoever purpose and of whatsoever materials constructed and every part thereof whether used as human habitation or not and includes foundation, plinth, walls, floors, chimneys, plumbing and building services, fixed platforms, verandah, balcony, cornice(or projection), and signs and outdoor display structures. Broadly speaking, buildings consist of three parts, namely (i) Foundation (ii) Plinth (iii) Superstructure.(i) Foundation: It is the lowest artificially prepared part ,below the surface of the surrounding ground ,which is in direct contact with sub-strata and transmits all the loads to the sub-soil.(ii) Plinth: It is the middle part of the structure, above the surface of the surrounding ground up to the surface of the floor (i.e., floor level), immediately above the ground.(iii) Super structure: The part of structure constructed above the plinth level (or ground floor level) is termed as superstructure.

Buildings are generally classified on the basis of occupancy and types of construction. Based on occupancy buildings are classified as Residential, Educational, Institutional, Assembly, Business, Mercantile, Industrial Storage and Hazardous.Materials of construction Rocks, Soils, Stones, Aggregates, Clay products, Limes, Cement, Mortars, Concrete, and Reinforced cement concrete.Rock: It is a hard and compact natural aggregate of mineral grains cemented by strong more or less permanent bonds. Rocks are classified as igneous, sedimentary, metamorphic depending upon their mode of formation. Rocks form the best foundation surface for buildings.Gravel: These are cohesion less aggregates of either rounded, sub-rounded, angular, sub-angular, or flat fragments of more or less unaltered rocks or minerals consisting of 90 percent of the particles greater than 2mm and less than 60mm.Sand: These are cohesion less aggregates of rounded, sub-rounded, angular, sub-angular or flat fragments of more or less unaltered rocks or minerals consisting of 90 percent of the particles of size greater than 0.06mm and less than 2mm.Silt: It is a fine grained soil with particles ranging in size from 0.002mm to 0.06mm with little or no plasticity. Silt is relatively impervious and also exhibits the slight tendency of swelling and shrinkage. This soil does not provide as good foundation surface as sand.Building stones: All those classes of natural rocks, rather pieces of rocks, which are finished in small building units for masonry construction, are termed as building stones, viz., lime stones, sand stones, marbles, granites, etc. These stones are used in building construction for foundations, walls, floorings etc.Coarse Aggregate: This consist of aggregate, such as stones, gravels, boulders, etc. either crushed or uncrushed but of such a size that most of which (more than 90%) is retained on 4.75mm IS Sieve. Coarse Aggregate is mainly used in production of concrete.

Fine Aggregate: This consist of sand such as natural sand crushed stone sand, crushed gravel sand or such other inert materials, most of which passes 4.75mm IS Sieve and contains not more than 5% coarser material. This fine aggregate is also used in preparing mortar, plaster, etc. in addition to its wide application in the production of concrete.Clay Bricks: It is like an artificial stone obtained by moulding clay in rectangular blocks of uniform size (19cm*9cm*9cm) and then by drying and burning these blocks.Mortars: It is a plastic mixture of binding material (like cement, lime, etc.), fine aggregates (like sand, surkhi, etc.), water and any admixture approved by the engineer in charge. This is used to bond masonry or other structural units.Cement Mortar: It is a mixture of cement, sand and water where cement acts as a binding material. The proportion of cement to sand varies from 1:2 to1:6 depending upon strength desired for a particular work.Cement Concrete: It is a mixture of cement, water, fine aggregate (i.e., sand) and coarse aggregate (i.e., crushed stone, crushed boulders, gravel, etc.) and any admixture approved by the engineer in charge. The proportion of cement, sand and aggregates is 1:2 or 3: 4Water-Cement Ratio: The ratio of the amount of water to the amount of cement by weight is termed as water-cement ratio, and the strength and quality of concrete primarily depend upon the ratio.Reinforced Cement Concrete(R.C.C.): Reinforced cement concrete is one in which the concrete and reinforcing metal, usually steel, are so combined as to act together as one material and to produce a more economical material than either acting alone.Foundations Foundation is the lowest artificially prepared part of a structure below the surface of surrounding ground which provides the base for the superstructure proper and transmits all the dead, superimposed and wind loads from a building to the soil on which the building rests in stressed beyond its safe load bearing capacity so that settlement, particularly uneven or relative settlement of the structure, is limited and failure of underlying soil is avoided.Types of foundations:(i) Shallow foundations(ii) Deep foundationsShallow foundations: These are those foundations which transfer the load to the soil at a level close to the lowest floor of the building. These foundations, of course, may be formed at great depth below ground surface where there is a basement.Ex: Strip, slab and raft (or mat) foundations.Deep foundations: These are those foundations which transfer the load to the sub-soil to a greater depth from ground surface and are generally employed only when the conditions of sub-strata or loading of structure or both, so dictate. They are generally provided when depth of foundation is more than 5 meter.Ex: Pile and pier foundations.

Masonry construction Masonry: Masonry is defined as an art of construction in which building units, such as clay bricks, sand-lime bricks, stones, precast hollow concrete blocks, concrete slabs, glass blocks, a combination of some of these building units, etc. are arranged systematically and bonded together to form a homogeneous mass in such a manner that they can withstand point or other loads and transmit them through the mass without failure or disintegration.Walls: The primary function of the walls is to enclose or divide space. In addition to this, they serve number of secondary functions such as supporting the weight of the upper floors and roofs, providing privacy, affording security and giving protection against heat, cold, sun and rain. Walls are of several types depending upon their positions, functions and types of construction.Non-Load Bearing Walls: Those walls, which support no vertical load (i.e., superimposed load) other than their own weight, are termed as non-load bearing walls.Curtain Wall (or Filler Wall or screen wall or Panel wall): It is an external self-supporting wall (i.e., external non-load bearing wall) which carries no other vertical loads but is subjected to lateral loads. In framed structures, this external non-load bearing wall built between columns or piers is termed as panel wall or filler wall.Partition wall(or Division wall): It is generally an interior non-load bearing wall dividing the space within the building, one storey or part storey in height, for providing privacy from sight, sound or both within a room or rooms. In some cases when partition is required to partially support girders of floor above it, it is called a bearing partition.Shear wall: Any wall designed to carry horizontal forces acting in its plane with or without the imposed loads is termed as a shear wall.Pier: It is a member similar to a column expects that it is bonded into load bearing walls at the sides to form an integral part and extends to full height of the wall. Its main function is to increase the stiffness of the wall to carry additional load or to carry vertical concentrated loads or resist lateral pressure without buckling.

Floor structure:Floors: These are the horizontal elements of building structure which divide a building into different levels for the purpose of creating more accommodation within a restricted space one above the other and provide support for the occupants, furniture and equipment of a building. Floor consists of components, namely, (i) A sub-floor, which imparts strength and stability to loads, and (ii) Floor covering or flooring, which provides a clean, smooth, impervious, durable and wear-resisting surface.Ground Floor: The bottom floor near the natural surrounding ground level is termed as the ground floor. The function of the ground floor is to give a clean, smooth, impervious (i.e., damp-resisting), durable and a wear-resisting surface. Ground floors rest directly on the ground and hence do not require the construction of a sub floor.Basement Floor: A floor when provided for the accommodation below the natural ground level (i.e., a basement), is termed as a basement floor. A basement floor is similar to ground floor except its location. Upper Floors: All other floors above the ground floor such as 1st floor, 2nd floor, 3rd floor, etc., are termed as upper floors. These floors, in addition to performing the functions of ground and basement floors, have to be stronger and stable. Not only this, they have also to act as horizontal barriers for the passage of sound and fire (i.e., they should possess sound insulation and fire-resistance properties) in vertical direction when building consists of more than one storey.Note: Walls act as vertical barriers for the passage of sound and fire.Suspended Floors: In a building consisting of more than one storey, all the floors except the bottom floor (either ground floor or basement floor) and top-most floor (i.e., roof or terrace are termed as suspended floors.Requirements of good flooring:A good floor should possess the following features. They are as follows1. It should have sufficient resistance to fire wear and tear, temperature changes and chemical reactions.1. It should have a sufficient resistance against dampness in buildings.1. It should have a pleating appearance.1. It should not cause noise.1. It should have a smooth and even surface.1. It should be cheap and economical to construct.

Roof structureA roof is the upper most part of a building, which is supported on structural member and covered with a roofing material, whose main function is to enclose the space and to protect the same from the weather effects such as rain, wind, heat, snow, etc. However, the choice of a roof type construction, in addition to weather effects should be based on various other considerations such as strength and stability under anticipated loads, heat insulation, lighting, ventilation, sound insulation, etc. Various types of roofs are constructed for different types of buildings with specific functional requirements, depending upon availability of materials and economy in construction.Roof components: A roof basically is made up of two components, namely (i) Roof-deck, and (ii) Roof covering or roofing.

Wall openings, recesses and related structuresDoor: A door is defined as a movable barrier, secured in an opening through a building wall or partition, for the purpose of providing an access to the building or rooms of a building.Cupboards and Shelves: These are the substitute of movable wardrobes which are provided in the recesses, (i.e., hollow wall portions) for storing valuable articles, clothes, etc.Arch: An arch is a structure, consisting of a number of small wedge-shaped units and joined together with mortar, which is constructed to bridge across the openings meant for doors, windows, ventilators, cupboards, etc., and to support the weight of the superimposed masonry.Lintel: It is a horizontal structural member which is used to span the openings for doors, windows, corridors and recesses such that it supports the weight of the structure above it. The function of a lintel is exactly the same as of an arch but is preferred to arch because of its simple construction and better stability. Though lintels are made of various materials such as wood, stone, brick, steel and R.C.C. but R.C.C lintels are widely used these days.Types of lintels: On the basis of material used in construction the lintel are classified into the following types.1. Wooden Lintels1. Stone Lintels1. Brick Lintels1. Steel Lintels1. Reinforced concrete lintels1. Reinforced brick lintels (i.e. R.B. Lintels.RoofsA roof is the upper most part of a building whose function is to provide a covering to keep out rain, snow, wind, etc.Classification of roofs: Roofs are classified as follows. They are1. Pitched roofs.1. Flat roofs.Pitched roofs: A pitched roof is a sloping roof. It is suitable for places where there is heavy snow fall or rain fall.Flat roofs: Common types of flat roofs are as follows1. Mauras terrace roof.1. R.C.C roof.R.C.C roof: R.C.C Roofs are widely used in modern construction. For spans up to 3m for ordinary loads, a simple R.C.C slab is adequate. For greater spans a simple R.C.C. beam and slab construction would be necessary. For constructing R.C.C. floors or slabs the following procedure is adopted.1. Erection of forms.1. Typing and placing reinforcing grills.1. Batching, mixing, placing and compacting.1. Stripping of forms.

Vertical transportationVarious structures such as stairs, lifts, ramps, ladders and escalators afford the means of communication between the various floors, (i.e., vertical transportation) either for everyday use or for escaping in the event of fire.Definition: Stairs are a series of steps arranged to connect different floors of a building an enclosure which contains the stair way is called stair case.Stair case can be constructed with timber, stones, bricks, steel etc but R.C.C. has almost replaced all other materials in our country and is widely used.Location of stair case: The following points should be observed in locating stairs in a building.1. A stair case should be located so that it is easily accessible from the different rooms of the building.1. In the case of public buildings it should be located near the entrance.Types of staircases: The common types of staircases are as follows.1. Straight types of stairs.1. Quarter turn stairs.1. Half turn stairs.1. Dog legged stairs,1. Open well stairs.1. Three quarter turn stairs.1. Spiral stairs.1. Bifurcated stairs.R.C.C Stairs: All types of stairs can be constructed with R.C.C. This stairs are designed mainly in two ways they are as follows.1. Stairs spanning horizontally.1. Stairs spanning longitudinally.

Building finishesSuch as plastering, pointing, painting, varnishing, distempering, white-washing, coloring, etc. Basically perform two functions-1. They give a protective coating to the surfaces which protects them from weather effects such as rain water frost heat etc., and 1. They provide decorative effects which add to the appearance of the surfaces and buildings as a whole.Plastering: Plastering is a thin coat of mortar applied on the surfaces of walls and ceilings, plastering covers the uneven surface, scales and hides joints of walls and same times used for decorative purposes. External plastering and other finishes applied for the purpose of protection and decoration are rendering.Objects of plastering: The main objects of plastering are as follows.1. To protect the exposed surfaces from atmospheric influence.1. To cover decorative workmanship and interior quality materials.1. To improve the appearance of the structure.Types of plasters: Plastering can be applied with the following mortars.1. Lime mortar.1. Cement mortar.1. Combination mortar or cement-lime mortar.The plaster can be one or two coats of thickness 12mm or 20mm respectively.Pointing: The finishing and protection of mortar joints of walls with cement mortar or lime mortar is known as pointing. Generally pointing is done with cement mortar (1:3) or (1:4).Objects of points: The main objects of point are:1. To protect the joints from the disintegrating effects of wetness.1. To serve as an alternative to plastering.1. To cover weak mortar used.1. To enhance the natural beauty of the construction materials.White washing and color washing: The internal and external walls are treated with one, two or three coats of white wash made lime and water. If a pigment is added then it is called color wash. The objects of white washings and color washings are: as follows.1. To present a pleasing appearance.1. To provide better distribution of light in the rooms.1. To serve as a disinfectant.Painting: Wooden and steel members and sometimes walls are painted for the following reasons.1. To protect the surface from weathering effects of the atmosphere.1. To prevent decay of timber and rusting of steel.1. To provide a pleasing appearance.Plumbing services and building services Plumbing Services: They include services like water supply-cold and hot, drainage and sanitation, and gas supply required for buildings.Building Services: They include the provision of services like lighting, electricity, acoustics and sound insulation, air-conditioning, heating and thermal insulation in buildings in favor of better efficiency and comfort.Miscellaneous termsForm work (or shuttering): The concrete, being a plastic material, requires temporary supports for casting it to different sizes and shapes in concrete construction till it gains sufficient strength. These temporary supports such as timber and steel forms or moulds are known as form work or shuttering. For circular concrete work such as arch, dome, etc. the temporary supports of timber, steel or masonry when used, the term centering is generally used instead of form work.Scaffolding (or scaffold): These are temporary erections constructed (when working height exceeds 1.5m) to support a number of platforms at workers and for carrying structural materials and appliances, during building operations. This temporary framework or scaffold is useful in building construction, demolition, maintenance and repair works. The scaffolding is erected either on one or both sides of the walls. For ordinary works scaffolding may be done on one side but for all first class works, the scaffolding must be provided on both sides of the wall. Shoring: Shoring is the means of providing temporary support to unsafe structures, the stability of which has been endangered due to the unequal settlement of the foundation or due to removal of adjacent buildings, or due to the bad workmanship, or due to any other reason. The temporary support to unsafe structures is provided till such time as they have been made stable. This is also used to give temporary support to a structure which might become unstable either during the alterations (i.e., remodeling) in the structure, itself, or during the alterations of adjacent foundations, such as the underpinning of foundations.Underpinning: It is the technique of either providing a new foundation below the existing one for strengthening purposes or replacing the existing one being inadequate, without endangering the stability of the existing structure. During underpinning, the existing building is temporarily supported by means of racking shores.Construction Equipment: The various types of equipment are used in different construction activities of building construction. The purpose of important ones is given below-1. Excavation Equipment,1. Boring Equipment,1. Concrete Mixers,1. Pile Driving Equipment,1. Vibrators,1. Dump Trucks ( or Dumpers),1. Cranes,1. Gantries and etc.

1.4 NOTATIONS USED IN THE DESIGN Ag : gross area of sectionAsc : area of compression steelAst : area of tension steelb : breadth of beam, width of slab, shorter dimension of rectangle column D : overall depth of a beam, slab, staircase slabd : effective depth of slab, beam, staircase slabd : depth of compression reinforcement from the highly compressive facefck : characteristic compressive strength of concretefy : characteristic strength of steel I : moment of inertia of gross section about centroidal axis Ld : development length of the barL : length of column or length of beamLx : length of the shorter span of the slabLy : length of the longer span of the slabM : bending momentMu : factored moment Mux : design moment about x-x axis Muy : design moment about y-y axis m : modular ratioP : axial load on a compressive memberPu : axial load for limit state designPt : percentage of tension reinforcementqu : calculated maximum bearing pressure S : spacing of slab reinforcement, stirrups Vu : shear force due to factored loadVus : Length of the shear reinforcementw : Distributed load per unit area X : Depth of the neutral axis at service loadXu : Depth of the neutral axis at the limit state of collapse c : shear stress in concrete cmax : Maximum shear stress in concrete with shear reinforcementA : Area of beam, column and footingsAst : Area of steel at mid span in shorter directionAstc : Area of steel at continuous edge in shorter directionAsty : Area of steel at mid span in longer directionAstyc : Area of steel at continuous edge in longer directionB.M : Bending Momentbw : Breadth of web or ribDL : Dead loadK : Neutral axis factorLeff : Effective lengthLL : Live loadS.F. : Shear ForceZ : Lever armcbc : Permissible compressive stress in steelst : Permissible tensile stress in steel

1.5 BUILDING BYE LAWS & REGULATIONS

1. Line of building frontage and minimum Plot sizes.1. Open spaces around residential building.1. Minimum standard dimensions of building elements.1. Provisions for lighting and ventilation.1. Provisions for safety from explosion.1. Provisions for means of access.1. Provisions for drainage and sanitation.1. Provisions for safety of works against hazards.1. Requirements for off-street parking spaces.1. Requirements for landscaping.1. Special requirements for low income housing.1. Size of structural elements.

1.5.1 ORIENTATIONOrientation means proper placement of rooms in relation to sun, wind, rain, topography and outlook and at the same time providing a convenient access both to the street and back yard

The factors that affect orientation most are as follows.

Solar heat Wind direction Humidity Rain fall Intensity of wind site condition Lightings and ventilation Solar heat: Solar heat means suns heat; the building should receive maximum solar radiation in winter and minimum in summer. For evaluation of solar radiation, it is essential to know the duration of sunshine and hourly solar intensity on exposed surfaces.

Wind direction: The winds in winter are avoided and are in summer, they are accepted in the house to the maximum extent. Humidity:High humidity which is common phenomenon is in coastal areas, causes perspiration, which is very uncomfortable condition from the human body and causes more discomfort.Rain fall:Direction and intensity of rainfall effects the drainage of the site and building and hence, it is very important from orientation point of view.

Intensity of wind: Intensity of wind in hilly regions is high and as such window openings of comparatively small size are recommended in such regions.

Site conditions:Location of site in rural areas, suburban areas or urban areas also effectsorientation, sometimes to achieve maximum benefits, the building has to be oriented in a particular direction.

Lighting:Good lighting is necessary for all buildings and three primary aims. The first is to promote the work or other activities carried on within the building. The second is to promote the safety of people using the buildings. The third is to create, in conjunction to interest and of well beings.

Ventilation:Ventilation may be defined as the system of supplying or removing air by natural or mechanical mean or from any enclosed space to create and maintain comfortable conditions. Operation of building and location to windows helps in providing proper ventilation. Sensations of comfort, reduction in humidity, removal of heat, supply of oxygen are the basic requirements in ventilation apart from reduction of dust.1.6 STATEMENT OF PROJECTType of Building :(G+3) multistoried school buildingDrawings :Building plan and Drawings of structural elements.

Geometric DetailsHeight of building :3.5 m (for each floor)Area of the plot: 63.76 m x 48.55 m = 3095m2Area of each floor:53.76 m x 38.55 m = 2072 m2

Walls thicknessOuter wall thickness: 0.23mInner wall thickness: 0.15mStaircasesNumber: TwoType of staircase: Doglegged staircasesWidth of landing: 1 mTread: 270 mmRise: 150 mmMaximum Number of steps per flight : 11Unit weight of different materialsRCC: 25 KN/m3PCC: 24 KN/m3Brick masonry: 19 KN/m3Loads consideredLive load on classrooms: 3 KN/m2Balcony and staircase: 4 KN/m2 Floor finishes: 0.6 - 1.2 KN/m2library room loads: 2 KN/m2office room load: 2.5 KN/m2Office room load: 2.5 KN/m2Washroom load: 2.0 KN/m2Grades of concrete and steel usedSlabs:M20 and Fe415Beams:M20 and Fe415Columns:M20 and Fe415Footings:M20 and Fe415BeamWidth of beam: 230 mm

ColumnNumber of columns: 116Shape of column: Rectangular columnColumn size: 230 mm x 400 mm FootingsNumber of footings: 116Type of footing: Isolated footingDesign methodsSlabs: Manual method (As per IS: 456-2000)Beams: Using Staad-ProColumns: Using Staad-ProFootings: Using Staad foundation.

CHAPTER 2LITERATURE SURVEY

The objective of our project is to analyze and design a MULTISTORIED SCHOOL BUILDING of capacity 1300-1500 students considering gravity loads (Dead load and Live load) using STAAD-Pro.According to Dr .B.C.PUNMIA,ASHOK KUMAR JAIN,ARUN KUMAR JAIN the author of limit state design of reinforced concrete structures as per IS 456:2000 published by laxmi publications(p) ltd. In their view the design of concrete structures can be done in 3 different methods i.e., working stress method , ultimate load method & limit state method .working stress method can be used by assuming concrete as an elastic material & only working stresses are considered, which in practical is wrong and in ultimate load we do consider only service loads but not working loads .where as in limit state method the combination of both methods will be taken which will attain both safe & serviceable condition.(i.e. semi-empirical approach) . But according to P.C.VARGHESE author of limit state design of reinforced cement concrete published in the year 1970.This treatise contains up to-date information on design, analysis & construction of engineered concrete structures, based on limit state design approach philosophy .this approach has been adopted internationally in India by IS 456(1978).Thus VARGHESE says the same thing as PUNMIA said and we think that the author agrees to the view of B.C.PUNMIA.In our view the author P.C. Varghese agrees with author B.C.PUNMIA and the design are all approximately same .so in the end we followed the author B.C.PUNMIA and designed the school building. Finally mostly the designs will be same and all will be using approximately same procedures .The drawings and designs of the project are submitted at the end of the report.

CHAPTER 3PLANNING

3.1 INTRODUCTION TO PRINCIPLE OF PLANNINGThe basic objective of planning of buildings is to arrange all the units of a building on all floors and at level according to their functional requirements making best use of the space available for a building. The shape of such a plan is governed by several factors such as climatic conditions, site location, accommodation requirements, local by-laws, surrounding environment, etc. in spite of the certain principles or factors, which govern the theory of planning are common to all buildings of all classes intended to be used for residential purposes. These principles, enunciated below, are right but just factors to be considered in planning.(01)Aspect(02)Prospect(03)Privacy(04)Grouping(05)Roominess(06)Furniture Requirement(07)Sanitation(08)Flexibility(09)Circulation(10)Elegance(11)Economy(12)Practical Considerations

1.Aspect: - Aspect means peculiarity of the arrangement of doors and windows in the external walls of a building which allows the occupants to enjoy the natural gifts such as sunshine, breeze, scenery, etc. Aspect is a very important consideration in planning as it provides not only comfort and good environment to live in but from hygienic point of view also.A room, which receives light and air from a particular side, is said to have aspect of that direction; and all such rooms making a dwelling need particular aspect. From this angle, the following aspects for different rooms are preferred:1. For kitchen E-aspect1. For dining room S-aspect1. For drawing and living rooms S-aspect or S-E aspect1. For bed rooms S-W-aspect or W-aspect1. For verandahs S-W-aspect or W-aspect1. For reading rooms, stores, class-rooms, studios, stairs, etc. N-aspect

From the above sun-diagram, it is clear that a kitchen should have an E-aspect, so that the morning sun would refresh and purify the air and keep the kitchen cool during the remaining period of the day. The dining, drawing and living rooms should have a S-aspect or S-E-aspect. The sun is towards the south during winter and more deviated towards the north during summer. Similarly, the bedrooms should have W-aspect or S-W-aspect, since the breeze required in summer will be available from west side only. But a verandah, a gallery or some such sun-shading device, must be provided on that side (i.e., W or S-W side) so as to protect the structure from the hot afternoon sun. as there will be no direct sun from the north and only diffused light will be available, hence, reading rooms, stored, stairs, studios, class-rooms, etc. are placed towards the north. 2.Prospect: - it includes the attainment of pleasing appearance by the use of natural beauties; disposition of doors and windows; and concealment of some undesirable views in a given outlook.Prospect and Aspect both demand disposition of doors and windows. For sake of either seeing or hiding certain views, window sites play a vital role.

3.Privacy: - Privacy is one of the important principles in the planning of buildings of all types in general and residential buildings in particular. Privacy requires consideration in two ways: 1. Privacy of one room from another.1. Privacy of all parts of a building from the neighboring buildings, public streets and by-ways.Privacy of the former type is attained by carefully planning the building with respect to Grouping, disposition of doors, mode of hanging doors, provision of small corridor or lobby etc. this can also be achieved by planning screens or curtains.Privacy of the latter type is easily secured by carefully planning the entrance and steering it with trees or creepers trained on a trellis.4.Grouping: - Grouping means the disposition of various rooms in the layout in a typical fashion so that all the rooms are placed in proper correlating of their functions and in proximity with each other. Every apartment of a building has got a definite function or functions and there is also some sort of sequence in between them. The objective of grouping of the apartments is to maintain the sequence of their functions with least interference. For example, in a residential building, dining room must be close to the kitchen; at the same time kitchen should be away from the drawing or the main living room, otherwise kitchen smells and smoke would detract them for their usefulness. Services must be nearer to and independently accessible from every bedroom. The water closets, urinals, etc. must be far away from the kitchen and dinning room, and so on.5.Roominess: - Roominess refers to the effect produced by deriving the maximum benefit from the minimum dimensions of a room. In other words, it is the accomplishment of economy of space at the same time avoiding cramping of the plan. It is essential particularly in case of residential buildings where large storage space is required, to make maximum use of every nook and corner of built-up area of the building before making an addition to the plinth area. 6.Furniture Requirements: - The functional requirement of a room or an apartment governs the furniture requirements. This is an important consideration in planning of buildings other than residential in particular and residential in general.In case of buildings other than residential, they are generally planned, with due thought to the furniture, equipment and other fixtures, to meet the needs of particular function required to be performed. This can be done by assuming the sufficient sizes of furniture pieces and then studying the circulation and space requirements round them.In case of residential buildings, a room whether intended for bed room or kitchen or drawing room, the architect should take into account the furniture positions of all types likely to be accommodated, so that the doors, windows and circulation space do not prevent from placing of sufficient number of pieces.7.Sanitation: - Sanitation consists of providing ample light, ventilation, facilities for cleaning and sanitary conveniences in the following manner:Light: - Light has two-fold significance, firstly it illuminates and secondly from hygienic point of view. Light in interior buildings may be provided by natural or artificial lighting. Glare in light distracts and disables the vision and hence the source of glare may be avoided.Uniform distribution of light is necessary particularly in schools, workshops, etc. A room should get sunlight as long as and as much as possible. Vertical windows are, therefore, better than horizontal ones.Generally, the minimum window area fir proper lighting should not be less than 1/10th of floor area; however, this may be increased to 1/5th for buildings like schools, workshops, factories, dormitories, etc.Good lighting is necessary for all buildings. This has three primary aims. The first is to promote the work or other activities carried on with in the building; the second is to promote the safety of people using the building; and the third it to create, in conjunction with the structure and decoration, a pleasing environment conducive to interest and a sense of well-being. Ventilation: - It is the supply of outside air wither positive ventilation or by infiltration into the building. Good ventilation is an important factor conducive to comfort in buildings. Poor ventilation or lack of fresh air in building, always produces headache, sleepiness, inability to fix attention, etc. ventilation may be natural or mechanical. In natural ventilation, the outside air is supplied into the building through windows, ventilators or other openings due to wind outside and convection effect arising from temperature or vapor pressure differences or both, between inside and outside the building.Cleanliness and sanitary conveniences: - Though the general cleaning and upkeep of the building is the responsibility of the occupants but even then some provisions to facilitate cleaning and prevention of dust are necessary in planning. The floors, as far as possible, should be of non-absorbent surface, smooth and proper slope should be given to facilitates washing with suitable outlets in the walls. Prevention of dust accumulation is essential. Dust helps the growth of bacteria and spread of the disease. Sanitary conveniences include the provision of bathrooms, water closets, lavatories, latrines, urinals, etc. in a building. Provision of such conveniences is not an optional matter but is a statutory requirement. 8.Flexibility: - Flexibility means planning a room or rooms in such a way, which thought originally designed for a specific purpose, may be used to serve other overlapping purposes also, as and when desired. This is particularly important for designing the houses for middle class families or other building where economy is the major consideration. 9.Circulation: - Circulation means internal thoroughfares or the movement space provided on the same floor either between the rooms or with in the room called horizontal circulation and between the different floors through stairs or lifts called vertical circulation. Passages, corridors, halls and lobbies serve the purpose of horizontal circulation, where as for vertical circulation normally stair or staircase, electric lifts, ramps, etc. are the means of access to different floors.10.Elegance: - Elegance is the effect produce by the elevation and general layout of the plan. The elevation, therefore, should speak out the internal facts and be indicative of the character.Elevation should be impressive and should be developed together with the plan simultaneously. With the economy limitations, elevations should be aesthetically good and attractive.11.Economy: - The economy may not be a principle of planning but it is certainly a factor, which effects planning. The economy may restrict the liberties of the architect and may also require certain alteration and omission in the original plan. The economy should not have any bad effect on grouping or aspect, however the prospect at the most to some extend can be sacrificed if need be. Economy should not have any evil effect on the utilities and safety of the structure.12.Practical Considerations: - The following practical points should be given due consideration in the planning of buildings:1. Strength and stability of structure, coupled with connivance and comfort, should occupy the first place of importance in planning.1. Simplicity and effects of strength lend a lasting beauty and mobility to a building.1. It should be remembered that a building or a house is immovable property and is built to last for several generations. One has, therefore, no right to practice false economy by erecting a weak structure.1. While planning it is necessary to keep provisions for either adding a wing or extending some part of house without dismantling.

CHAPTER 4ANALYSIS4.1 ANALYSIS OF A STRUCTUREAnalysis of a structure involves in determination of the following : 1. Positioning and orientation of column of columns 1. Position of beams 1. Spanning of slabs 1. Layout of stairs 1. Selecting proper type of footing The basic principle in deciding the layout of component members is that the loads should be transferred to the foundation along the shortest path. 4.2 POSITION OF COLUMNS 1) Columns should be preferably located at or near the corners of a building and at the intersections of beams/walls. Since the basic function of the columns is to support beams which are normally placed under the walls to support them, their position automatically gets fixed. 2) Select the position of columns so as to reduce bending moments in beams. When the locations of two columns are very near, then one column should be provided instead of two at such a position so as to reduce the beam moment. 3) Avoid larger spans of beams. When the center to center distance between the intersection of walls is large or when there are no cross walls, the spacing between two columns is governed by limitations of spans of supported beams because spacing of columns decides the span of beam. As the span of the beam increases, the required depth of the beam, and hence its self-weight, and the total load on beam increases. It is well known that the moment governing the beam design varies with the square of the span and directly with the load. Hence with the increase in the span, there is considerable increase in the size of the beam. On the other hand, in the case of column, the increase in total load due to increase in length is negligible as long as the column is short. Therefore the cost of the beam per unit length increases rapidly with the span as compared to beams on the basis of unit cost. Therefore the larger span of the beams should be preferably avoided for economy reasons. In general, the maximum spans of beams carrying live loads upto 2 kN/m^2 may be limited to the following values. Beam type Cantilevers Simply supported Fixed/continuous

rectangular 3meters 6meters 8meters

flanged 5meters 10meters 12meters

4) Avoid larger center to center distance between columns. Larger spacing of columns not only increases the load on the column at each floor posing problem of stocky columns in lower storeys of a multi storied building. Heavy sections of column lead to offsets from walls and obstruct the floor area. 5) The columns on property line need special treatment. Since column footing requires certain area beyond the column, difficulties are encountered in providing footing for such columns. In such cases, the column may be shifted inside along a cross wall to make room for accommodating the footing within the property line. 4.3 ORIENTATION OF COLUMNS 1) Avoid projection of column outside wall. According requirements of aesthetics and utility, projections of columns outside the wall in the room should be avoided as they not only give bad also obstruct the use of floor space and create problems in furniture flush with the wall. Provide depth of the column in the plane of the wall to avoid such offsets. 2) Orient the column so that the depth of the column is contained in the major plane of bending or is perpendicular to the major axis of bending. When the column is rigidly connected to right angles, it is subjected to moments of addition to the axial load. In such cases, the column should be so oriented that the depth of the column is perpendicular to major axis of bending so as to get larger moment of inertia and hence greater moment resisting capacity. It will also reduce Leff/D ratio resulting in increase in the load carrying capacity of the column. 3) It should be borne in mind that increasing the depth in the plane of bending not only increases the moment carrying capacity but also increases its stiffness, there by more moment is transferred to the column at the beam column junction. 4) However, if the difference in bending moment in two mutually perpendicular directions is not large the depth of the column may be taken along the wall provided column has sufficient strength in the plane of large moment. This will avoid offsets in the rooms. 4.4 POSITION OF BEAMS 1) Beams shall normally be provided under the walls or below a heavy concentrated load to avoid these loads directly coming on slabs. Since beams are primarily provided to support slabs, its spacing shall be decided by the maximum spans of slabs. 2) Slab requires the maximum volume of concrete to carry a given load. Therefore the thickness of slab is required to be kept minimum. The maximum practical thickness for residential/office/public buildings is 200mm while the minimum is 100mm. 3) However, for large span, normally higher L/D ratio is taken to restrict the depth from considerations of head room, aesthetics and psychological effect. Therefore spans of beams which require the depth of beam greater than one meter should be avoided.

4.5 SPANNING OF SLABS This is decided by supporting arrangements. When the supports are only on opposite edges or only in one direction, the slab acts as a one way supported slab. When rectangular slab is supported along its four edges, it acts as one way slab when Ly / Lx > 2 and as two way slab for Ly/Lx < 2. however two way action of the slab not only depends on the aspect ratio Ly / Lx and but also on the ratio of reinforcement in the two directions. Therefore, designer is free to decide as to whether the slab should be designed as one way or two way.1) A slab normally acts as a one way slab when the aspect ratio Ly/Lx >2, since in this case one way action is predominant. In one way slab, main steel is provided along the short span only and the load is transferred to two opposite supports only. The steel along the long span just acts as distribution steel and is not designed for transferring the load but to distribute the load and to resist shrinkage and temperature stresses. 2) A two way slab having aspect ratio Ly / Lx < 2 is generally economical compared to one way slab because steel along the spans acts as main steel and transfers the load to all its four supports. The two way action is advantageous essentially for large spans and for live loads greater than 3kN/m^2. For short spans and light loads, steel required for two way slab does not differ appreciably as compared to steel for one way slab because of the requirement of minimum steel. 3) Spanning of the slab is also decided by the continuity of the slab. 4.6 CHOICE OF FOOTING TYPE 1) The type of footing depends upon the load carried by the column and bearing capacity of the supporting soil. It may be noted that the earth under the foundation is susceptible to large variations. 2) It is necessary to conduct the survey in the area where the proposed structure is to be constructed to determine the soil properties. Drill holes and trail pits should be taken and in situ plate load test may be performed and samples of soil tested in the laboratory to determine the bearing capacity of soil and other properties. 3) For framed structure under study, isolated column footings are normally preferred except in case of soils with very low bearing capacities. If such soil or black cotton soil exists for great depths, pile foundations can be appropriate choice.

CHAPTER 5STRUCTURAL DESIGN Structural design for framed R.C.C structure can be done by three methods:1. Working Stress Methods1. Ultimate Strength Methods1. Limit State Method

5.1 WORKING STRESS METHOD OF DESIGN

It is earliest modified method of R.C.C structures. In this method structural element is so designed that the stress resulting from the action of services load as computed in linear elastic theory using modular ratio concept do not exceed a pre-designed allowable stress which is kept as some fraction of ultimate stress, to avail a margin of safety. Since this method does not utilize full strength of the material it results in heavy section, the economy aspect cannot be fully utilized in the method.

5.2 ULTIMATE STRENGTH METHOD OF DESIGN

This method is primarily based on strength concept. In this method the structural element is proportioned to with stand the ultimate load, which is obtained by enhancing the service load of some factor referred to as load factor for giving desired margin of safety. Since this method is based on actual stress strain behavior of the material, of the member as of the structure that too right up to failure, the values calculated by this method agree well the experiment results.

5.3 LIMIT STATE METHOD DESIGN

During the past several years, extension research works have been carried out on the different aspects of the research in the actual behavior of member and structure has led to the development of design and approach of LIMIT STATE METHOD OF DESIGN.5.4 LIMIT STATE CONCEPTIn limit state method the working load is multiplied by partial factor of safety in accordance with clause 36.4.1 of IS 456- 2000; And also the ultimate strength of material is divided by the partial safety in accordance with clause 36.4.1 of IS 456-2000; and also the ultimate strength of the material is divided by partial safety in accordance with clause 36.4.2 of IS-456-2000. Partial safety factor is introduced to reduce the probability of failure to about zero. When a structure or apart of a structure becomes unfit for use, it is said to have reached a limit state, unfitness for use can arise in various ways and aim of limit state method of design is to provide an acceptable probability that the structure will not reach any of the limit states during its service life span. Limit state can be broadly classified into two main categories.1. LIMIT STATE OF COLLAPSE: It is the limit state on attainment of which the structure is likely to collapse. It relates to stability and strength of the structure. Design to this limit ensures safety of the structure from collapse.1. LIMIT STATE OF SERVICEABILITY: It relates to performance or behavior of structure at working loads and is based on causes affecting serviceability of the structure. This limit state is concerned with cracking and deflection of the structure.

CHAPTER 6LOAD CALCULATIONS6.1 INTRODUCTIONLoads and properties of materials constitute the basic parameter of a R.C structures. Both of them are basically of a varying nature .for such a quality of varying nature, it is necessary to arrive of a single representative value. Such value is known as characteristic value. The value to be taken in design which provides appropriate or designed margin of safety is known as design values. The loads are taken as per IS-875 and the material properties like characteristic value are taken from IS-456. 6.2TYPES OF LOAD The various types of loads acting on the structure which needs consideration in building design as follows:-0. dead loads0. live loads0. wind loads0. earthquake loads0. other loads

Dead load :- IS : 875 (part - 1)Dead loads are permanent or stationary loads which are transferred to the structure throughout their life span. Dead loads are mainly due to self weight of structural members, permanent partitions, fixed equipments and fittings. These loads shall be calculated by estimating the quantity of each material and then multiplying it with the unit weight. The unit weights of various materials used in building construction are given in the code IS: 875 (Part-1).

The unit weight of commonly used building materials are given in the following table. MATERIAL UNIT WEIGHT (KN/m3)1. Plain concrete24.0 KN/m31. Reinforced concrete25.0 KN/m31. Brick masonry, cement plaster20.0 KN/m31. Fly ash5.0 KN/m31. Wood8.0 KN/m31. Steel78.5 KN/m31. Floor finishes0.6 1.2 KN/m3 Imposed loads or Live loads :- IS : 875 (part - 2) Live loads or movable loads without any acceleration or impact. These are assumed to be produced by the intended use or occupancy of the building including weights of movable partition or furniture etc. The imposed loads to be assumed in buildings Live Load on beams: This is the live loads of slab which comes on beams in form of triangular or trapezoidal variation.Live load on slabs:-These are taken as, Residential building = 3 KN/m2 Commercial building = 3.5 KN/m2 Institutional building =3KN/m2

LIVELOADS: In accordance with IS 875 (Part-2)(i)Live load on slabs=3.0 KN/m2(ii) Live load on passages=4.0 KN/m2(iii)Live load on stairs=4.0 KN/m2Wind load:- Wind load is primary horizontal load caused by movement of air relative to earth. The details of design wind load are given is IS : 875 (part - 3) Wind load is required to be considered in design especially when the height of the building exceeds two times dimensions transverse to the exposed wind surface. For low rise building say up to 4 to 5 stories the wind load is not critical because the moment of resistance provided by the continuity of floor system to column connection and walls provided between column connection and walls provided between columns are sufficient to accommodate the effect of these forces. Earthquake forces :- (As per IS 1893-2002)Earthquake shocks causes movement of foundation of structures. Due to inertia additional forces develop on the super structure. The impact of earthquake on structures depends on the stiffness of the structure; stiffness of the soil media, height and location of the structure etc. Accordingly, the country has been divided into several zones depending on the magnitude of the earthquake. Depending on the problem, one of the following two methods may be used for computing the seismic forces.1. Seismic coefficient method1. Response spectrum methodThe details of these methods are prescribed in IS: 1893 code and also in National Building Code of India

Snow loads :- (As per IS 875 Part 4)These are important loads for structures located in areas having snow fall, which gets accumulated in different parts of the structure depending on projections, height, slope etc. of the structure. The standard values of snow loads are specified in Part 4 of IS: 875.Shrinkage, creep and temperature effect :-Shrinkage, creep and temperature (high or low) may produce stresses and cause deformations like other loads and forces. Hence, these are also considered as loads which are time dependent. The safety and serviceability of structures are to be checked following the stipulations of clauses 6.2.4, 5 and 6 of IS: 456-2000 and Part 5 of IS: 875.6.3 DESIGN LOADS The variation in loads due to unforeseen increase in the loads, constructional inaccuracies, type of limit state etc., are taken into account to define the design load. The design load is given by : Design load = characteristic load Where: = partial safety of loads. Partial safety factor( ) for loads (according to IS : 456 2000) Load combination limit state of collapse limit state of serviceability DL IL WL DL IL WLDL + IL 1.5 1.0 1.0 1.0 -DL + WL 1.5 - 1.5 1.0 - 1.0DL + IL + WL 1.2 1.2 1.2 1.0 0.8 0.8

* This value is considered when stability against overturning or stress reversal is critical Notes: (1) DL = dead load IL = imposed load WL = wind load (2) While considering earth quake effects. Substitute EL for WL. (3) Since the serviceability relates to the behavior of structure at working load the partial safety factors for limit state of serviceability are unity. (4) For limit state of serviceability, the values given in this table are applicable for short term effects. While assessing the long term effects due to creep, the dead load and that part of the dead load and live load likely to be permanent may only be considered. 6.4 CRITICAL LOAD COMBINATIONS While designing a structure, all load combinations, in general are required to be considered and the structure is designed for the most critical of all. For building up to 4 storeys, wind load is not considered; the elements are required to be designed for critical combination of dead load and live load only. For deciding critical load arrangements, we are required to use maximum and minimum loads. For this code prescribes different load factors as given below: Maximum load = wmax = 1.5(DL + LL + wall load) Minimum load = wmin = 1.0((DL + LL + wall load)The maximum positive moments producing tension at the bottom will occur when the deflection is maximum or curvature producing concavity upwards is maximum. This condition will occur when maximum load (i.e. Both DL and LL) covers the whole span while minimum load (i.e. only DL) is on adjacent spans.

(a) Consideration may be limited to combination of : 1) Design dead load on all spans will full design live loads on two adjacent spans (for obtaining maximum hogging moment.) 2) Design dead load on all spans with full design imposed load on alternate spans ( to get maximum span moment.) 3) When design imposed load does not exceed three-fourths of the design dead load, the load arrangement may be design dead load and design imposed load on all the spansCode of practice for rcc design All reinforced concrete structural design in our country should conform to the recently revised Indian Standard Code IS: 456-2000, Code of practice for plain and reinforced concrete (Fourth revision).The Bureau of Indian Standards have released over the years several hand books to facilitate reinforced concrete structural designers to design routine structural elements quickly by referring to the various tables and graphs presented in the hand books.The following hand books will serve as useful design aids for structural concrete designers.SP: 16-1980: Design aids for reinforced concrete to IS: 456SP: 24-1983: Explanatory hand book on IS: 456SP: 34-1987: Hand book on concrete reinforcement and detailingSP: 23-1982: Hand book on concrete mixes

6.5 LOAD CALCULATIONS1} Calculation of DL on beams Self-weight of beams = 0.23 * 0.4 * 25 = 2.3 KN/mWeights due to external walls on beam = (3.5-0.35) * 0.23 * 20 = 14.49 KN/m -------------------- Total = 16.79 KN/m Amount of distributed load coming from slab either in the form of triangular load or Trapezoidal load = {w Lx (3 (Lx / Ly) 2} / 6 or {w Lx / 3} And loads from cantilever slabs i.e. = w LxHere, w = self wt of slab, Lx = shorter dimension, Ly= longer dimension of slab panel 2} Calculation of DL on classroom slab Self-weight of the slab = 0.15 * 25 = 3.75 KN/m2 Floor finish on the slab = 1.0 KN/m2 Sunken load on toilet slabs = 3.0 KN/m ------------------------ Total = 7.75 KN/m2 DESIGN CONSTANTSFck= Characteristic strength of concrete 20 N/mm2Fy= Characteristic strength of steel 415 N/mm2

Structural analysisThe procedure of structural analysis is simple in concept but complex. In detail, it involves the analysis of a proposed structure to show that its resistance or strength will meet or exceed a reasonable expectation. This expectation is usually expressed by a specified load or the demand and an acceptable margined of safety that constitutes a performance goal for a structure. The performance goals structural design is multifaceted. Foremost, a structure must perform its intended function safely over its useful life.

The concept of useful life implies consideration of durability and established the basis for considering the cumulative exposure to time varying risks (i.e. corrosive environments, that performance is inextricably linked to cost, owners, builders, and designer must considers economic limit to the primary goal of safety and durability.

In the view of the above discussion, structural designer may appear to have little control over the fundamental goals of structural design except to comply with or exceed the minimum limits established by law. While this is generally true, a designer can still do much to optimize the design through alternative means and methods that can for more efficient analysis techniques, creative design detailing, and the use of innovative construction materials and methods. In summary the goal of structural design are defined by law and reflect the collective interpretation of general public welfare by those involved in the development and local adoption of building could. Alex Bendex first formulated this procedure in 1914 based on the applications of compatibility and equilibrium of compatibility and equilibrium conditions. This method derives its name from the facts that supports and displacements are explicitly computed. Set up simultaneous equation is formed from the solution of these parameters and the join moment in each or computed from these values.

UNIT 7STAAD-PRO INTRODUCTIONSTAAD PROThis chapter reviews about some of the fundamental concepts of structural design and present them in a manner relevant to the design of light frame residential structures. The concepts from the basis for understanding the design procedures and overall design approach addressed in the remaining chapter of the guide. With this conceptual background, it is hoped that the designer will gain a greater appreciation for creative and efficient design of home, particularly the many assumptions that must be made.

The world is leading Structural Analysis and Design package for Structural Engineers.

Starting the Program. Creating a New Structure. Creating Joints and Members. Switching On Node and Beam Labels. Specifying Member Properties. Specifying Material Constants. Specifying Member Offsets. Printing Member Information. Specifying Supports. Specifying Loads. Specifying the Analysis type. Specifying Post-Analysis Print Commands. Specifying Steel Design Parameters. Performing Analysis and Design.

Viewing the Output File . Verifying results on screen both graphically and numerically. World's #1 Structural Analysis and Design software supporting Indian and major International codes. The choice of 0.2 million Structural Engineers worldwide, STAAD pro is guaranteed to meet all your structural engineering needs. STAADpro features state of the art user interface, visualization tools, powerful analysis and design engines with advanced finite element (FEM) and dynamic analysis and design to visualization and result verification STAADpro is the professional first choice. STAADpro was developed by practicing engineers around the globe. It has evolved over 20 years and meets the requirements of ISO 9001 certification. STAADpro has building codes for most countries including US, Britain, Canada, Australia, France, Germany, Spain, Norway, Finland, Sweden, India, China, Japan, Denmark and Holland.

Structural Analysis And Design: STAAD-III, the world's most powerful and popular structural analysis and design software is in use across the globe since 1980. Now it is available in the form of STAAD.Pro which consists of STAAD + STARDYNE +FEMkit + Visual Draw .STAAD.Pro is a comprehensive, general purpose software for integrated structural analysis and design. STAAD.Pro may be utilized for analyzing and designing practically all types of structures - buildings, bridges, towers, transportation, industrial and utility structures. STAAD.Pro implements the most modern technologies in today's Computer-Aided-Engineering. It unifies leading-edge graphics and visualization techniques with proven and time tested analysis and design. A live, unified database provides seamless integration across all mission critical application from concept design/analysis to detail design, simulation and visualization.

STAAD.Pro Overview:

"Concurrent Engineering" based user environment for model development, analysis, design, visualization and verification. Pull down menus, floating toolbars, tool tip help. Flexible Zoom and multiple views. Isometric and perspective views 3D shapes. Built-in Command File Editor. Simple Command Language. Graphics/Text input generation. State-of-the-art Graphical Pre and Post Processor. Rectangular/Cylindrical Coordinate systems. Joint, Member/element, Mesh Generation with flexible user-controlled numbering. Efficient algorithm minimizes disk space requirements. FPS, Metric or SI units. Presentation quality printer plots of Geometry and Results as part of run output.

Graphics Environment: Model Generation 0. Interactive Menu-driven Model Generation with simultaneous 3D display. 0. 2D and 3D Graphic Generation using rectangular or polar coordinate system. 0. Segments of repetitive geometry may be used to generate complex structural models. 0. Generate Copy, Repeat, Mirror, Pivot, etc, or quick and easy geometry generation. 0. Quick/easy mesh generation. 0. Comprehensive graphics editing. 0. Graphical Specification and Display of Properties, Loadings, Supports, Orientations. 0. Import AutoCAD DXF files. 0. Access to Text Editor. Model Verification

1. 2D/3D drawings on screen as well as on plotter/printer. 1. Full 3D shapes for Frames, Elements. 1. Sectional views or views with listed members only. 1. Isometric or any rotations for full 3D viewing. 1. Display of properties, Loadings, Supports, Orientations, Joint/Member numbering, Dimensions, Hidden line removed, etc. 1. Plot manipulation according to the size, rotation, viewing origin and distance.

Analysis & Design:

1. Static Analysis 1. 2D/3D analysis based on state-of-the-art Matrix method to handle extremely larger job. 1. Beam, Truss, Tapered Beam, Shell/Plate Bending/Plane Stress. 1. Full/partial Moment Releases. 1. Member Offset Specification. 1. Fixed, Pinned and Spring Supports with Releases. Also inclined Supports. 1. Automatic Spring Support Generator. 1. Linear, P-Delta Analysis, Non-Linear Analysis with automatic load and stiffness correction. 1. Multiple Analysis within same run. 1. Active/Inactive Members for Load-Dependent structures. 1. Tension-only members and compression-only members, Multi-linear spring supports. 1. CIMSTEEL Interface. Load Types and Load Generation:

1. Loading for Joints, Members/Elements including Concentrated, Uniform, Linear, 1. Trapezoidal, Temperature, Strain, Support Displacement, Prestressed and Fixed-end Loads.

1. Global, Local and Projected Loading Directions.

1. Uniform or varying Element Pressure Loading on entire or selected portion of elements.

1. Floor/Area Load converts load-per-area to member loads based on one-way or two-way actions.

Concrete Design:

1. Design of Concrete Beam/Column/Slab/Footing as per all major international codes.

1. Numerical and Graphical Design outputs with complete reinforcement details.

1. IS 456-2000 for RCC design implemented.

1. RC detailer as per IS 456-2000 has been implemented which has given a new dimension to RCC design never witnessed in STAAD before.

CHAPTER 8DESIGNS

8.1 STRUCTURAL DESIGN0. Design of slabs0. Beam Design. 0. Column Design.0. Foundation Design.

8.1.1 S L A B S

Slab is plain structural members forming floors and roofs of building whose thickness is quite small compared to their other dimensions. These carry load primarily by flexure and are in various shapes such as square, rectangular, circular and triangular in buildings, tanks etc. inclined slabs may be used as ramps for multistoried as parking. A staircase is considered to be an inclined slab.Slab may be supported by beams or by walls and may be simply supported or continuous over one or more supports. When all four edges are off same length (aspect ratio Ly/Lx = 1), then the load on slab will be equally distributed to all the four edges. But as the length of long span increases (aspect ratio > 1) the tendency of the load on slab would be such that more load will tries to flow along short span (to the beams supporting long edges) than along long span(the beams supporting short edges). When the length of long span further increases to such extent that Ly/Lx > 2 then the total load on slab will tends to flow along only short span and no load flows along long span.It has to be noted that what everything said above regarding flow of load is just the tendency based on the aspect ratio. However the actual flow of load along any direction depends upon the relative stiffness of the slab along both the directions. According to ELASTIC THEORY the transfer of load along any direction is proportional to the stiffness of the slab along that direction. More is the stiffness along any particular direction; more is the flow of load along that particular direction. On the basis of the direction of transfer of the load, slabs are classified into two types:1) One Way Slab2) Two Way Slab

One Way Slab: When the load on the slab is transferred along only one direction then the slabs are called one way slabs. In general, when the aspect ratio (Ly/Lx) is greater than 2, then the load on slab is made to transfer along only the short span by stiffening the slab along short span by providing steel reinforcement only along short span. The steel along the short span is called MAIN STEEL. A minimum reinforcement is provided along the direction perpendicular to the main steel reinforcement also, in order to keep the main steel bars in position and prevent the temperature and shrinkage stresses. This reinforcement is called SECONDARY REINFORCEMENT or (DISTRIBUTION REINFORCEMENT). Because of this secondary reinforcement a small part of the load will be transferred along the long span, to the beams supporting short edges.In practice, some situations arise, especially in case of along long span and no load is transferred along short span, even when the aspect ratio Ly/Lx is greater than Two (but not greater than around 2.5).This can be made possible by arranging main steel reinforcement along only long span and secondary steel along short span.Two Way Slab: When load on the slab is transferred along both directions then the slabs are called two way slabs. In Two Way Slabs, the slab is stiffened along both directions by providing main steel reinforcement along both the directions. In general, slabs are designed as Two Way Slabs when aspect ratio Ly/Lx 3 KN/m2 and Lx > 3.5 m then only two way slabs are advantageous or economical. As per the minimum requirement of reinforcement, unless LL and Lx values are less than what is specified above, there will not be any advantage in particular in differentiating between One Way Slabs and Two Way Slabs.Despite the fact that the two way slabs are economical the reason behind choosing the one way slabs is the functional requirement. In order to avoid certain structural hindrances such as columns in a hall, and heavier sections for beams, one way slabs are preferred.The thickness of the reinforced concrete slabs ranges from 75mm to 300mm slabs are designed just like beams keeping the breadth of slab as unity depending on the system of units. Thus the total slab is assumed to the consisting of strips of unit width compression reinforcement is used only in exceptional basis in a slab. Shear stress in a slab are very low and hence shear reinforcement is never provided and if necessary it is preferred to increase the depth of the slab to reduce the stress than providing the reinforcement. Temperature reinforcement is provided at right angles to the main longitudinal reinforcement in a slab. The design of the slab is purely is accordance with the code IS-456 2000 the designing process of the slabs the following assumption are made.M20 Concrete and Fe415 steel is used both for design and execution purpose.1. The overall depth of the slab is restricted to 150mm with a clear cover of 20mm.1. The main reinforcement consists of Tor steel bars and temperature reinforcement consists of mild steel bars.1. The total depth of the section is obtained from the maximum bending moment of all moments on the span.

Steps to be followed in the slabs design of ONE-WAY SLAB:

1. Assume suitable thickness or depth (D) of the slab for working out its self weight.

1. Calculate 1. Dead load1. Live load1. Floor Finish load1. Imposed load (if any)

1. Calculate effective span for the slab.

1. Find the type of slab by the governing formula

If (One-Way Slab)

If(Two-Way Slab)1. Calculate the maximum bending moment (M) by the Near middle of Span

1. Required effective depth from max. B.M. Consideration.

d = 1. Check for required effective depth of slab from stiffness/deflection considerationAssume percentage of tension reinforcement provided and corresponding value of modification factor from graph in fig 3 of IS 456Calculate required effective depth (d) from stiffness/deflection controlConsiderationNote: Basic values for different kinds of slab are given in clause 23.1 of IS 456.

1. Calculate the area of steel per meter width

M = Distribution ReinforcementArea of distribution steel Adist = 0.15% of bd for Mild SteelOr Adist = 0.12% of bd for Tor Steel Select suitable diameter (d) of the bar and find their center to center spacing.9. Check for shear by following the steps given below.0. Calculate Maximum shear force (v) from the governing formula.0. Calculate Nominal shear stress by formula

=

Calculate from table 13 of IS 456 the value of permissible shear ()for the balanced percentage of reinforcement. Obtain value of K clause 47.2.1.1 of IS 456 and work out value of permissible shear in slab by the formula

= k

If = k the slab is safe in shear and requires no shear reinforcement else shear reinforcement shall be provided.

10.Check for the development length at supports.

Ld < 1.3 + Lo Steps to be followed in the design of TWO-WAY SLAB:

1. Assume suitable thickness or depth (D) of the slab for working out its self weight.1. Calculate Deed Load 1. Live load1. Floor finish Load1. Imposed Load (if any)

1. Assume suitable thickness of depth (D) of the slab for working out its self-weight.

1. Calculate effective spans both in respect of short span (lx) as well as long span (ly)1. To find the type of slab by the governing formula.

If (One-Way Slab)

If(Two-Way Slab)1. Calculate the maximum Bending Moments per unit width along short span and long span by I.S code method.Mx = x .w. lx2My = y.w.lx21. Calculate the effective depth of the slab from Max B.M consideration.

M = (or)

d =

1. Consideration check for required effective depth of slab from stiffness/deflection control.Assume percentage of tension reinforcement and corresponding valued of modification factor from graph in fig 3 IS 456.Calculate required graph depth (d) from stiffness/deflection control consideration.

D = Note: Basic Value for different kinds of slabs is given in clause 23.1 of IS 456.This should work out to be less than the value of effective depth adopted in design.1. Calculate the area of steel per meter width along each span by

M = Check for min. reinforcementAst =0.12% bdSelect suitable diameter (X) of the bar and find their center to center spacing.

1. Check for shear by following the steps given below.

0. Calculate Maximum shear force (v) from the governing formula.0. Calculate Nominal shear stress by formula

=

Calculate from table 13 of IS 456 the value of permissible shear ()for the balanced percentage of reinforcement. Obtain value of K clause 47.2.1.1 of IS 456 and work out value of permissible shear in slab by the formula

= k

If = k the slab is safe in shear and requires no shear reinforcement else shear reinforcement shall be provided.Check for the development length at supports.

Ld < 1.3 + Lo 1. Torsional reinforcement; As per code, area of steel of torsion reinforcement per Meter width of slab in each layer of mesh at each corner of the slab= Area of reinforcement for max + ve B.M.8.1.2 BEAMS A reinforcement concrete beam should be able to resist tensile, compressive and shear stresses induced in it by the on the beam. Concrete is fairly strong in compression but very weak in tension. Paint concrete beams are thus limited in carrying capacity by the low tensile strength. Steel is very strong in tension. Thus, the tensile weakness of concrete is overcome by the provision of reinforced steel in the tension zone round the concrete to make a reinforce concrete beam. The beams and slabs in concrete structure are cast monolithic. Hence the structure becomes a slab, which is stiffened by concrete ribs in which the intermediate beams act as T beam, and beams round the staircase. Lift openings, supports frames, etc. act as L beams. The portion of the slab that acts as a-flange of T or 1 beams on its own thickness and span. The flange of the T-beam provides the necessary resistance to compression while the vertical rib provides the depth and hence the necessary lever arm. The width of the rib must be such as to accommodate the tensile reinforcement. A certain portion of the slab on either slab may be considered as forming the compression flange. If the supporting beam happens to be an end beam, the flange of the beam is present only on side of the beam, in such a case is called an L- beam.For a T-beam or L-beam action the following condition shall be satisfied:I. The slab shall be cast integrally with the web, or the web and the slab shall be effectively bounded together in any other manner, andII. If the main reinforcement of the slab is parallel to the beam, the transverse reinforcement shall not be less than 60% of the main rein for cement and at mid span of the slab.Hence the sections of the beam are taken as rectangle and the beams are doubly reinforced.The necessity of providing steel in the compression region arises due to two reasons,A) The main reinforcement of a singly reinforced beam cannot be increased by more than 25% of a balanced section by increasing the steel only on tension side.B)At the support of a continuous beam the bending moment changes its sing. Such a situation may also arise in the design of a beam.Beams may be singly reinforced or doubly reinforced. If case of singly reinforced beam, the main reinforcement is provided near the faces of the beam subjected to tension and compression.

A doubly reinforced section is generally provided under the following conditions.1.When the depth and breadth of the beam are restricted and it has to resist greater bending moment than a singly reinforced beam of that section would do.2.When the beam is continuous over several supports, the section of the beam at the support is usually designed as doubly reinforces section.3.When the member is subjected to eccentric loading.4. When the bending moment in the member reverses according to the loading conditions e.g., the wall of the under ground R.C.C storage reservoir, brackets etc.,5. When the member is subjected to shocks, impact or accidental lateral thrust.

DESIGN SPECIFICATION ACCORDING TO IS: 456-2000 Effective depth of beams is the distance between the centroid of the area of tension reinforcement and the maximum compression fiber, excluding the thickness of the finishing material not placed monolithically.

Control of deflection

The deflection of a structure or a part there of shall not adversely affect the appearance or efficiency of the structure of finishes or partitions. The deflection shall generally be limited to the following:The final deflection due to all loads including the effects of temperature, creep and shrinkage are measured from the as-cast level of the support of the floor, roofs and all other horizontal members not normally exceed span/250.The deflection including the effects of temperature, creep and shrinkage occurring after erection of partitions and the application of finishes should not normally exceed span/350 or 20mm whichever is less.Doubly reinforced beamsA doubly reinforced beam is that in which reinforcement is provided both for tension as well as compression face.ConditionsIn continuous beams where tension is developed at both face near the center of the beam and on the top face near the supports. From architectural point of view if the size of the beam is restricted.T- beamsWhenever slabs are casted monolithically a part of the slab acts along with the beam, as a result the cross-section of the beam appears to the similar to the letter T. Hence the beam is called as T-beamConditions

1. The flange must be under compression.1. Both slab and beam must be casted monolithically or they must be connected together by some other means.1. The main reinforcement of the slab must be casted perpendicular to the beam.Shear

A beam subjected to shear force and bending moment experience diagonal tension. Vertical shear force alone is not as critical when compared with the result due to the intersection of bending moment and shear force.The resultants of these stresses produce diagonal tension, which may develop crack in the beam.To take care of this resultant diagonal tension shear reinforcement is provided in two forms.1. Cranked bars1. Stirrups1. Vertical1. Inclined. 8.1.3 COLUMNA Column is a vertical member in a structure used to transfer the loads from slabs to the foundation below. The load from slab may be either directly transferred to the columns or indirectly transferred to the columns through the beams. Only those vertical members in a structure whose slenderness ratio is greater than 3 are called columns.

If the slenderness ratio is less than 3, those vertical members are called PEDESTALS.If the slenderness ratio is more than 12, those members are called SLENDER (or Long Columns).If the slenderness ratio is less than 12, those vertical members are called Short Columns.However, the maximum slenderness ratio of a column should not exceed 60.In addition to the compressive loads, the columns may be subjected to tension due to either accidental eccentricity of load or due to bending moment owing to the end restraint. To resist this tension some amount of steel has to be provided longitudinally. To keep this longitudinal steel in position and to prevent buckling of bars, transverse reinforcement (generally called as TIES) has to be provided.The common shapes of Columns are in practice are:1) Circular Columns2) Square Columns3) Rectangular ColumnsIn case of Circular Columns, the minimum numbers of longitudinal bars provided are 6.In case of Square Columns or Rectangular Columns, the minimum numbers of longitudinal bars provided are 4.`When all other factors such as Grade of Materials, Cross Sectional area etc., are constant a short column will carry more load than a long column. In other words the load carrying capacity of a column decreases as its length increases.Effective LengthThe effective length of a column is defined as the length between the points of contra flexure of the buckled column. The code has given certain values of the effective length for normal usage assuming idealized and condition shown in appendix D of IS 456 (table 24)

A column may be classified as follows based on the type of loading.1. Axially loaded column.1. A column subjected to axial load and uni-axial bending.1. A column subjected axial loads and bi-axial bending.

Axially Loaded ColumnsAll compression members are to be designed for a minimum eccentricity of load into principal directions. IN practice, a truly axially loaded column is rare, if not non-existent. Therefore, every column should be designed for an eccentricity. Clause 22.4 of IS code specifies the following eccentricity, emin for the design of column in the direction under consideration.Axial Load and Uniaxial BendingA member subjected to axial force and uniaxial bending shall be designed on the basis of 1. The maximum compressive strain in concrete in concrete in axial compression is taken as .0021. The maximum compression strain in concrete at the highly compressed extreme fiber in concrete subjected to axial compression and when there is no tension on the section shall be 0.0035 minus 0.75 times the strain at the least compressed extreme fiber.Design charges for combined axial compression and bending are given in the form of interaction diagrams in which curves for Pu /fck bD Vs Mu /fck b D2 are plotted for different values of p/ fck where P is the reinforcement percentage (N/C)Axial Load and Biaxial BendingThe resistance of a member subjected to axial fore and biaxial bending shall be obtained on the basis of assumptions given in 38.1 and 38.2 with neutral axis so chosen as to satisfy the equilibrium of load and moments about two axes.Alternatively such members may be designed by the following equation: (N/C)Mux,Muy = Moment about x and y-axis due to design loadMuxl, muyl = Maximum uniaxial moment capacity for an axial load of pu, bending about x and y axis respectivelyAn is related to pu/puzPuz = 0.45 x fck x Ac + 0.75 x fy x AscFor values of Pu/puz = 0.2 to 0.8, the values of an varies from 1 to 2For values less than 0.2 =1.0For values greater than 0.8, = 2.0

8.1.4 FOUNDATIONFoundations are structural elements that transfer loads from the buildings or individual column to the earth. If these loads are to be properly transmitted, foundations must be designed to prevent excessive settlement of rotation, to minimize differential settlement and to provide adequate safety against sliding and overturning most foundations may be classified as follows:1. Isolated footings under individual columns.These may be square, rec