Planning, Designing, and Estimating a Hostel Building.

Project on

“PLANNING, DESIGNING AND ESTIMATING A HOSTEL BUILDING” 

Submitted

by

ANSARI MOHD. ABUSAAD

GOUR ABDUL AHAD

KHAN MOHD. AHESAN

HUSSAIN KASHIF

Under guidance of

PROF. Faizan Shaikh

                                         CHAPTER 1

                          INTRODUCTION

Engineering is a professional art of applying science to the efficient conversion of natural resources for the benefit of man. Engineering therefore requires above all creative imagination to innovative useful application for natural phenomenon. Structural design is the primary aspect of civil engineering. The very basis of construction of any building, residential house or dams, bridges, culverts, canals etc. is designing. Structural engineering has existed since humans first started to construct their own structures.

        The future of structure engineering mainly depends on better and more effective methods of designing the structures so that they serve better and are also economical. The advancement of innovative and environmentally friendly building materials is also coming up. They can give a new direction to the structural engineering field as the availability of concrete and steel is not only decreasing but also they are harmful to the environment.

        Our project is based on the designing of RCC structure G+4 is located at that place where the RCC structure is going on normally all the building is G+4. This building is design on three purposes for the safety, economy and serviceability. 

1.1 MOTIVATION:        

As students are following the technological era they want to learn, succeed and compete with this society so they join engineering college and so as I did but as the college was far away from my place I liked to stay in hostel because there were many people in the start who were travelling 3 to 4 hrs. daily to achieve their goal. But I was shocked knowing that the college actually don’t have any hostel. I decided to stay in room nearby college and I rented a flat with some of my college mate as they were facing the same problem. But there were so many problems to face. One of the major problems was food. We were dependent on ourselves for cooking our own food.

        

So back then along with my friends I had decided to construct a hostel building in our college campus for the students who spend their most of the time in travelling.

1.2 PROBLEM DEFINITION:

Initially we were thinking that constructing hostel would be a very easy task but when we started to construct our dream project we came to know that planning, designing and estimating were the enigmatic task. We thought that surveying the field would be a easy task and it won’t consume our much time but when we actually started surveying the land we faced it as a most difficult task as we have to go through lot of climatic changes.

1.3 OBJECTIVE OF PROJECT:

The main objective of our project is to plan, design and estimate a hostel building in our college campus so that it should accommodate around 200 students and provide them all the essential facilities that a student hostel should have. Also to get educated about the new designing software for modern building structural design and applying quantitative skills for estimating building cost.

1.4 ADVANTAGES:

Admission – By going through the facilities provided by college the no. of students will be attracted towards college and it will increase the no. of admissions taken by the students.

Profit – As the no. students taking admission will increase the profit will be increase simultaneously to our college.

Studies – Students who will stay in hostel can give there more times to studies instead of travelling.

Punctuality – Students who have to wait at station to travel to college by means of bus or auto rickshaw, etc. can now attend all lectures at their respected time more punctually.

 

                                         

                                        CHAPTER 2

                         LITERATURE REVIEW

        Dharne Sidramappa Shivashaankar, Patil Raobahdur Yashwant presents the various limitations in design and construction practices along with the feedback to overcome the limitations and make the structures safer to take the earthquake forces. The paper focuses on software used in the civil engineering for analysis and design, construction methods/practices, use of materials, types of structures, experiments for earthquake studies, quality control parameters etc.

        Prashanth.P, Anshuman.S, Pandey. R. K, Arpan Herbert present day leading design software’s in the market. Many design companies’ use this software’s for their project design purposes. So, this project mainly deals with the comparative analysis of the results obtained from the design of a regular and a plan irregular (as per IS 1893) multi storey building structure when designed using STAAD-Pro and ETABS software’s separately.

These results will also be compared with manual calculations of a sample beam and column of the same structure designed as per IS 456.

Ismail Sab, Prof.S.M. Hashmi, generated 3D analytical model of twelve storeyed buildings for different buildings Models and analyzed using structural analysis tool ETABS. To study the effect of infill, ground soft, bare frame and models with ground soft having concrete core wall and shear walls and concrete bracings at different positions during earthquake; seismic analysis using both linear static, linear dynamic (Response spectrum method) has been performed. The analytical model of the building includes all important components that influence the mass, strength, stiffness and deformability of the structure.

        Swati D.Ambadkar, Vipul S. Bawner, analysed G +5 building by using STAAD PRO. Analysis is done for various variations such as 1) Terrain with few or no obstructions having heights below 1.5 m. 2) Terrain with obstructions having heights between 1.5 to 10 m. 3) Terrain with numerous closely spaced obstructions having the size of building structures up to 10 m in height.4) Terrain with numerous large high closely spaced obstructions. According to Internal Pressure Coefficients (Cpi) provided for that various variations. This analysis is done for wind speed 44 m/s, 47 m/s, 50 m/s. Results obtained from STAAD-PRO analysis are used for obtaining significant relations of moments, forces and displacement with wind speeds.

Moments, forces and displacement obtained from all cases are compared with wind speeds, according to their percentage of opening provided for various variations.

   

                                   CHAPTER 3

                                    PLANNING

3.1 PRINCIPLES OF BUILDING PLANNING:

When we first start to plan a new building construction work to begin we definitely need to remember some basic principles of building planning. Some of the basic principles of planning of a building construction are given below.

  1. An engineer or architect should prepare the building plan according to the demand, economic status & taste of the owner and also the purpose of the building is to be built whether residential, commercial etc.
  2. The design of the building should be compatible with the surrounding structures & the weather.
  3. Sufficient air and sunlight should be allowed to the building for healthy building environment.
  4. Privacy must be maintained especially in residential building planning.
  5. Proper security system should be introduced for safety and reliability.
  6. Fire safety alarm and firefighting materials should be provided within the range of the inhabitants of the proposed building structure.
  7. The value of the structure should be maintained in building plans.
  8. Follow the associated building codes closely for proper building construction. Example: Civil Engineering Codes.

Some important factors to consider for building planning are as follows.

3.2 THE DESIGN PROCESS:

Every design process is unique, and this generic step-by-step guide to the design process is indicative only. The number of steps varies depending on the complexity of the project and whether we’re building a new home, renovating or simply making a few small home improvements.

For an overview of the entire process of building or renovating a home, read this article in conjunction with Preliminary research and The construction process.

Our Home is immediately relevant to anyone designing and building a new home, and it can guide renovations and additions (see Planning home improvements; Renovations and additions; Repairs and maintenance).

If a plan house is our preference, buying a home off the plan shows which design features to look for. We can usually customise our design to some extent.

If we’re buying an apartment, Buying and renovating an apartment indicates the features to look for and how to renovate or make small improvements.

3.2.1 PRELIMINARY RESEARCH:

This first step is explained in detail in Preliminary research, which covers:

Fig 1. Location from satellite view.

3.2.2 SITE ANALYSIS:

Visit the site with our designer to do a ‘SWOT’ analysis (strengths, weaknesses, opportunities and threats). This is our first opportunity to work with our designer to see if our objectives align. It can take the form of a paid consultation or can be part of the design contract outlined in the next step.

On the site, consider:

Fig 2. Different views.

Fig 3. Site area.

 3.2.3 CONCEPT DESIGNS:

Designers often prepare several concept designs to communicate their thinking and allow we to assess them against our brief. They can range from a simple bubble diagram sketch on the back of an envelope, through to hand drawn concepts of form and spatial arrangements. Analyze them in light of the information in the Passive design articles that apply to our climate zone and raise any questions with our designer.

Fig 4. Conceptual structure.

Concept designs can help make initial sustainability choices.

Concept designs should consider construction systems but not lock them in unless they are a fundamental component of our brief. The choice of high or low mass materials and the amount of mass required in floor, walls or roof to achieve thermal comfort varies depending on other design decisions including glass to mass ratios and heating and cooling systems (see Thermal mass).

Input from a building sustainability consultant or assessor can be very useful at this stage to ensure that every opportunity to achieve high level thermal performance is locked in while the design is still very flexible.

3.2.4 DESIGN DEVELOPMENT:

Through discussion with our designer, choose the concept design that best suits our needs. The designer then develops the concept into a preliminary layout. More than one concept can be developed in this way but each additional concept developed may increase design fees.

This important stage usually includes preliminary room arrangements, window opening sizes and orientation, indication of indoor–outdoor flow, furniture layouts and preliminary choice of construction systems. Spend time visualising our household living in the design at this stage. Revisit our analysis of our current home. Have problems been overcome? Have new ones been created?

The decision-making process for materials selection also progresses during this step as external and internal finishes are considered. Take this opportunity to identify sustainably sourced materials with low life cycle environmental impact (see Materials).

Tip:

To help with visualisation of views, breeze and sunlight entry, consider making a simple cardboard model of the design with cut-out windows and place it on our site at different times of day and season. Make it ourselves by gluing our designer’s plans and elevations onto cardboard, or ask them to make a model for us.

Construction costing is based on a rate per square metre, as is the cost of heating and cooling our home. The larger the home, the more it costs to build and operate. Reducing the size and reallocating that budget to sustainable features is an important focus during this stage of design. Trimming just a few square metres from each room can pay for double glazing or a photovoltaic array.

The larger the home, the more it costs to build and operate.

Size does matter — a smaller house saves in many ways

Measure each piece of furniture (new or existing) we intend using in our home and ask our designer to draw and print them at scale so we can cut them out and experiment with various layouts on the concept plans. We can visualise how our family might live in the house and identify any problems — particularly oversized spaces. Make a detailed list of our storage requirements. Add each list to the brief and check each one off before signing off on the final design.

Computer-based building design and modelling tools, such as house energy rating tools like Accurate, BERS Pro and FirstRate5, can predict environmental performance and model the thermal performance benefits of window numbers, size, placement and orientation as well as various mass levels in different construction systems (see www.nathers.gov.au). Complete this analysis before finalising our design and choice of construction system. Later solutions or changes may be expensive.

Prepare our landscape design at this stage. Landscaping makes many critical contributions including shading the building or windows, diverting breezes, ensuring privacy, creating delight and saving water (see Landscaping and garden design; Water).

A landscape designer can add shade, character and delight to our home.

It is common for designers to discuss the proposal with council planners and inspectors at this stage to identify any issues requiring resolution.

Fig 5. Deducted area from actual plan.

3.2.5 FINAL DESIGN:

Make our final design and selection decisions of the following matters in light of advice from the relevant Our Home article:

This stage is often the greatest test of commitment, for both us and our designer, to achieving an environmentally sustainable home.

Final design is often when budget overruns become apparent and cost reductions are then made. This point is usually the single greatest threat to the environmental sustainability of our home because sustainability features are often considered ‘optional’ and eliminated in the trade-off process even though they may have relatively low cost.

These trade-offs are best managed by dividing our project into stages. Features we don’t need right away can be built or added later. Include the sustainability features at the start and reduce our bills from the day we move in. These features are usually less expensive to incorporate in the initial build than to add later. Additional spaces or rooms designed into a total concept at the outset can be added cost effectively when future finances allow.

Changes made after this stage has been signed off will likely add to design costs.

When both parties are satisfied with the design, submit the final design drawing to council for planning approval before design detailing, if a staged approval process is desirable. This approach can accommodate design changes required by council more cost effectively. The alternative approach (combined planning and construction approval) is more expensive if council requires design changes, which need to be made to both sets of drawings.

   


Fig 6. 3-d view of the hostel building.

Fig 7. Plan showing footings.

3.2.6 DESIGN DETAILING:

They (or more detailed versions) are also given to builders when they are invited to tender for the work and form the basis of our contract with our builder.

Final schedules of materials and quality of finishes are documented in the specification by reference to Australian Standards, industry definitions of practice and desired outcomes that are not noted on the plans. Specifications are critical to achieving sustainable outcomes because it is here that sustainable inclusions, practices and finishes are spelled out and linked to the contract.

Fig 8. Structure with complete detailing/labelling.

                                              Fig 9. Plan showing ground floor.

                          Fig 10. Plan showing first, second, third and fourth floor.

                                             

                                                Fig 11. Plan showing terrace.

Plan of building G+4

Type of building = Educational

Location = Boisar at Theem College of Engineering

Built-up Area = 4274 sq. m

Plot Area = 5786 sq. m

                                           CHAPTER 4

DESIGNING

4.1 STRUCTURAL DESIGN:

Structural design is an art and science of understanding the behavior of structural members subjected to loads and designing them with economy to give a safe, serviceable and durable structure.

4.2 THE PRINCIPLE ELEMENTS OF A R.C.C BUILDING FRAME:

The principle element of R.C.C building frame consists of:

  1. Slabs to cover large area.
  2. Beams to support slabs and walls.
  3. Columns to support beams.
  4. Footing to distribute concentrated column loads over a large of the supporting soil such that the bearing capacity of soil is not exceeded.

In a framed structure the load is transferred from slab to beam, from beam to column and then to the foundation and soil below it.

4.3 STAGES IN STRUCTURAL DESIGN:

The process of structural design involves the following stages:

  1. Structural Planning.
  2. Action of Forces and Computation of Loads.
  3. Method of Analysis.
  4. Member Design.
  5. Detailing, Drawing and Preparation of Schedules.

4.3.1 STRUCTURAL PLANNING:

After getting an architectural plan of the buildings, the structural planning of the building frame is done. This involves determination of the following

  1. Positioning and Orientation of Columns.
  2. Position of Beams.        
  3. Spanning of Slabs.
  4. Layout of Stairs.
  5. Selecting Proper Type of Footing.

4.3.1.1 POSITIONING AND ORIENTATION 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.
  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 storey of a multi storeyed 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.

4.3.1.2 POSITIONING 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. Avoid larger spacing of beams from deflection and cracking criteria. Larger spans of beams shall also be avoided from the considerations of controlling the deflection and cracking. This is because it is well known that deflection varies directly with the cube of span and inversely with the cube of depth i.e., L3/D3. Consequently, increase in D is less than increase in span L which results in greater deflection for larger span.
  4. 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.
  5. The maximum and minimum spans of slabs which decide the spacing of beams are governed by loading and limiting thickness.

4.3.1.3 SPANNING OF SLABS:

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 ways.

  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. Decide the type of the slab. While deciding the type of the slab whether a cantilever or a simply supported slab or a continuous slab loaded by UDL it should be borne in mind that the maximum bending moment in cantilever (M = wL2 / 2) is four times that of a simply supported slab (M=wL2/8), while it is five to six times that of a continuous slab or a fixed slab (M=wL2/10 or wL2/12) for the same span length.
  5. Similarly, deflection of a cantilever loaded by a uniformly distributed load is given by:

         δ = wL4 /8EI = 48/5 *(5wL4 / 38EI)

         Which is 9.6 times that of a simply supported slab = (5wL4 / 384 EI).

4.3.1.4 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. Even under one small building the soil may vary from soft clay to hard murum.
  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.
  4. If columns are very closely spaced and bearing capacity of the soil is low, raft foundation can be an alternative solution. For column on the boundary line, a combined footing or a strap footing may be provided.

4.3.2 ANALYSIS OF A STRUCTURE:

The different approaches to structural analysis are: -

  1. Elastic analysis
  2. Plastic analysis
  3. Staad pro

4.3.2.1 ELASTIC ANALYSIS:

Elastic analysis is used in working stress method of design. Limit analysis is further bifurcated as plastic theory applied to steel structures and ultimate load method of design, and its modified version namely Limit State Method for R.C. Structures, which includes design for ultimate limit state at which ultimate load theory applies and in service state elastic theory applies and in service elastic theory applies and in services state elastic theory is used.

          A brief introduction: We come across various structures in our day to day life ranging from simple ones like the curtain rods and electric poles to more complex ones like multistoried buildings, shell roofs, bridges, dams, heavy machineries, automobiles, aero planes and ships. These structures are subjected to various loads like concentrated loads, uniformly distributed loads, uniformly varying loads, random loads, internal or external pressures and dynamic forces. The structure transfers its load to the supports and ultimately to the ground.

          Treating an entire structure as a single rigid body and finding the reactions from supports is the first step in analyzing a structure. While transferring the loads acting on the structure, the members of the structure are subjected to internal forces like axial forces, shearing forces, bending and torsional moments. Structural analysis deals with analyzing these internal forces in the members of the structures.

          It is easier to analyze a multistory building with the help of „frame analysis‟ than the analysis of individual beams. The frame analysis of roof, ground floor and an internal frame is done.

4.3.2.2 PLASTIC ANALYSIS:

Basics and Principles of Plastic Analysis:

Definition:

Plastic analysis is defined as the analysis in which the criterion for the design of structures is the ultimate load. We can define it as the analysis inelastic material is studied beyond the elastic limit (which can be observed in stress strain diagram). Plastic analysis derives from a simple mode failure in which plastic hinges form. Actually the ultimate load is found from the strength of steel in plastic range. This method of analysis is quite rapid and has rational approach for analysis of structure. It controls the economy regarding to weight of steel since the sections required by this method are smaller than those required by the method of elastic analysis. Plastic analysis has its application in the analysis and design of indeterminate structures.

Basics of Plastic analysis:

Plastic analysis is usually based on the idealization of stress strain curve as perfectly plastic. In this analysis it is assumed that width thickness ratio of plate elements is small so the local buckling does not occur. Broadly speaking the section will be declared as perfectly plastic. Keeping in mind these assumptions, it can be said that section will reach its plastic moment capacity and after that will be subjected to considerable moment at applied moments.

Principles of Plastic analysis:

There are following conditions for plastic analysis

  1. Mechanism condition
  2. Equilibrium condition
  3. Plastic moment condition

Mechanism condition:

When the ultimate load is reached collapse mechanism usually formed.

Equilibrium condition:

Σ FX=0, Σ FY=0, Σ Mxy=0

Plastic moment condition:

The bending moment at any section in the structure should not be more than the full plastic moment (moment at which plastic hinges form and structure moves to failure) of the section.

Plastic moment:

If we consider the case of simply supported beam, when the load is gradually applied on it, bending moment and stresses increases. As the load is increased, the stresses in fibers of beam reach to yield stress. At this stage the moment which has converted the stresses into the yield stress is said to be as Plastic moment. it is usually denoted by Mp.at this stage the beam member cannot take up any additional moment but may maintain this moment for some amount of rotation and acts like a plastic hinge (hinge means having no capacity to resist moment). Plastic hinge behaves like an ordinary hinge allowing free rotation about itself. The yield moment and plastic moment has relationship which can be described by help of following relation:

My = 2/3 Mp

In calculation of plastic moments, the term shape factor has its own importance. Shape factor can be defined as the ratio of plastic moment to yield moment is said to be as the shape factor. Shape factor depend usually on shape of the cross section.

For rectangular cross section the plastic moment can be calculated as:

Yield stress x (bh2/4)

When the load is applied on the body which is elastic (return to its shape after the load is removed), it will show resistance against deformation, such a body is called to be as structure. On the other hand, if no resistance is shown against the body, then it is known as mechanism. When plastic hinges equal to n+1 form in the structure, then the structure will collapse (where n is degree of indeterminacy of structure). It means if the plastic hinges in structures increases in number than their degree of indeterminacy, structures move towards collapse.

Plastic hinge and degree of indeterminacy:

Whenever plastic hinge forms in the structure, equilibrium is obtained. As the result the degree of static indeterminacy reduces by one with the formation of one plastic hinge. We can say that if the structure has 'n' number of degree of indeterminacy, its degree of indeterminacy reduces and it becomes determinate structure if 'n' number of plastic hinges forms in it.

4.3.3 ANALYSIS OF STRUCTURE BY STAAD-PRO:

The innovative and revolutionary new STAAD-PRO is the ultimate integrated software package for the structural analysis and design of buildings. Incorporating near about 20 years of continuous research and development, this latest STAAD-PRO offers unmatched 3D object based modeling and visualization tools, blazingly fast linear and nonlinear analytical power, sophisticated and comprehensive design capabilities for a wide-range of materials, and insightful graphic displays, reports, and schematic drawings that allow users to quickly and easily decipher and understand analysis and design results.         

From the start of design conception through the production of schematic drawings, STAAD-PRO integrates every aspect of the engineering design process. Creation of models has never been easier - intuitive drawing commands allow for the rapid generation of floor and elevation framing. CAD drawings can be converted directly into STAAD-PRO models or used as templates onto which STAAD-PRO objects may be overlaid. The state-of-the-art SAPFire 64-bit solver allows extremely large and complex models to be rapidly analyzed, and supports nonlinear modeling techniques such as construction sequencing and time effects (e.g., creep and shrinkage).

          Design of steel and concrete frames (with automated optimization), composite beams, composite columns, steel joists, and concrete and masonry shear walls is included, as is the capacity check for steel connections and base plates. Models may be realistically rendered, and all results can be shown directly on the structure. Comprehensive and customizable reports are available for all analysis and design output, and schematic construction drawings of framing plans, schedules, details, and cross-sections may be generated for concrete and steel structures.

4.4 DESIGN PHILOSOPHIES:

Reinforced concrete structures can be designed by using one of the following design philosophies.

  1. Working Stress Method (WSM)
  2. Ultimate Load Method (ULM)
  3. Limit State Method (LSM)

Working stress method used over decades is now practically out dated. It is not used at all in many advanced countries of the world because of its inherent drawbacks. The latest I.S. Code gives emphasis on Limit State method which is the modified version of Ultimate load method.

The limit state method has proved to have an edge over the working stress design from the view point of economy.

4.5 LOAD CONSIDERATION:

Loads are basic parameters affecting the design of a R. C.C. structure. It is basically of varying nature. The correct assessment of loads/forces on a structure is a very important step and serviceable design of structure.

4.6 TYPE OF LOADS:

The loads are broadly classified as vertical loads, horizontal loads, and longitudinal loads. The vertical loads consist of dead load, live load, impact load. The horizontal loads comprise of wind load and earth quake load. The longitudinal loads (viz., tractive and braking forces are considered in special cases of design of bridges, design of gantry girders etc.)

4.6.1 DEAD LOAD:

Dead loads are permanent or stationary loads which are transferred to the structure throughout their life span. Dead load is primarily due to self-weight of structural members, permanent partition walls, fixed permanent equipment and weighs of different materials.

dead load (IS 875 part-1)

Sr. No.

Material

Density

1

concrete

2500 Kg/m3 

2

Brick wall

2000 Kg/m3 

3

Soil

1800 Kg/m3 

4

Water

1000 Kg/m3 

5

plaster

2000 Kg/m3 

                                           Table no. 1. Density of different materials.

4.6.2 IMPOSED LOADS OR LIVE LOADS:

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 load is to be assumed in buildings.

Sr. No.

Occupancy

Loads

1

Residential floors

200 Kg/m2 

2

Basement with car parking

250 Kg/m2 

3

Toilets and Baths

200 Kg/m2 

4

Staircases

300 Kg/m2 

5

Corridors

300 Kg/m2 

6

Terraces (accessible)

150 Kg/m2 

                            Table no. 2. Live load for different sections in a building.

        

4.6.3 IMPACT LOAD:

Impact load is caused by vibration or impact or acceleration. A person walking produces a live load but soldiers marching or frames supporting lifts and hoists produce impact loads. Thus impact load is equal to imposed incremented by some percentage depending on the intensity of impact.

4.6.4 WIND 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)2.2

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 storeys 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.

         Further in limit state method the factor for design load is reduced to 1.2(DL + LL + WL) when the wind is considered as against the factor of 1.5 (DL + LL) when wind is not considered.

Sr. No

Parameter

Value

Remark

1

Basic wind Speed (Vb)

13 km/h

For BOISAR

2

Height of the building

16.2 m

3

Terrain Category

2

Clause 5.3.2

4

Terrain Class

B

5

Probability factor (K1)

1.0

Clause 5.3.1

6

Terrain Height and structure size (K’2)

1.03

Clause 8.2 & 8.2.1, Table-33

7

Topography Factor (K3)

1.00

Clause 5.3.3

        Table no. 3. Different factors to consider while designing.

Design Wind Pressure, Pz = 0.6 x (Vb x k1 x k’2 x k3)2

4.7 LOAD COMBINATION:

Sr. No

Load Combinations

1

1.5 (Dead Loads + Live Loads)

2

1.2 (Dead Loads + Live Loads +/- Seismic load in X direction)

3

1.2 (Dead Loads + Live Loads +/- Seismic load in Y direction)

4

1.5 (Dead Loads +/- Seismic load in X direction)

5

1.5 (Dead Loads +/- Seismic load in Y direction)

6

1.2 (Dead Loads + Live Loads +/- Wind load in X direction)

7

1.2 (Dead Loads + Live Loads +/- Wind load in Y direction)

8

1.5 (Dead Loads +/- Wind load in X direction)

9

1.5 (Dead Loads +/- Wind load in Y direction)

                                        Table no. 4. Combination of loads.

                                           

4.8 DESIGN CRITERIA OF COLUMNS:

After obtaining (1) vertical load, (2) moment due to horizontal load on either axis (3) moment due to vertical load on either axis acting on each column at all floor levels of the building.

•Columns are designed by charts of SP-16 (Design Aids).

•Design of each column is carried out from the top of foundation to the roof varying the amount of steel reinforcement for suitable groups for ease in design.

REPORT BY ANALYSIS BY USING STAAD-PRO.

C O L U M N   N O.    245  D E S I G N   R E S U L T S

M25                    Fe415 (Main)               Fe415 (Sec.)

LENGTH:  3000.0 mm   CROSS SECTION:  650.0 mm X  400.0 mm  COVER: 40.0 mm

** GUIDING LOAD CASE:    3 END JOINT:   127  SHORT COLUMN

REQD. STEEL AREA   :      589.19 Sq.mm.

REQD. CONCRETE AREA:    73648.66 Sq.mm.

MAIN REINFORCEMENT : Provide   8 - 12 dia. (0.35%,    904.78 Sq.mm.)

(Equally distributed)

TIE REINFORCEMENT  : Provide  8 mm dia. rectangular ties @ 190 mm c/c

SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KNS-MET)

----------------------------------------------------------

Puz :   3101.76   Muz1 :    116.64   Muy1 :    193.42

INTERACTION RATIO: 0.99 (as per Cl. 39.6, IS456:2000)

SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KNS-MET)

----------------------------------------------------------

WORST LOAD CASE:     3

END JOINT:   127 Puz :   3196.43   Muz :    133.97   Muy :    225.08   IR: 0.86

C O L U M N   N O.   3791  D E S I G N   R E S U L T S

M25                    Fe415 (Main)               Fe415 (Sec.)

LENGTH:  3000.0 mm   CROSS SECTION:  650.0 mm X  400.0 mm  COVER: 40.0 mm

** GUIDING LOAD CASE:    3 END JOINT:  1379  SHORT COLUMN

REQD. STEEL AREA   :     2346.35 Sq.mm.

REQD. CONCRETE AREA:   257653.66 Sq.mm.

MAIN REINFORCEMENT : Provide  12 - 16 dia. (0.93%,   2412.74 Sq.mm.)

(Equally distributed)

TIE REINFORCEMENT  : Provide  8 mm dia. rectangular ties @ 255 mm c/c

SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KNS-MET)

----------------------------------------------------------

Puz :   3628.90   Muz1 :    168.29   Muy1 :    289.73

INTERACTION RATIO: 1.00 (as per Cl. 39.6, IS456:2000)

SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KNS-MET)

----------------------------------------------------------

WORST LOAD CASE:     3

END JOINT:  1379 Puz :   3648.82   Muz :    173.04   Muy :    299.66   IR: 0.97

4.9 SLAB DESIGN:

Type of slab

Based on Ratio of long span to short span

Based on Edge Conditions

Maximum diameter –

Maximum distance between bars-

The horizontal distance between parallel main reinforcement bar is ≤3d or 300mm.

The horizontal distance between parallel reinforcement bar provided against shrinkage and temperature is ≤5d or 300mm whichever is less.

Design of Slab:

Live Load = 2 kN/m2.

Floor to Floor Height = 3 m.

M20/Fe415

fck = 20 Mpa

fy = 415 Mpa

Design of slab S2:

Ly/Lx = 6.1/3.6

         = 1.69

Hence slab will be designed as two-way slab as per IS - 456 - 2000

  1. Depth of slab:

(Leff will be the shorter span)

d = Leff/ {[(20 + 26)/2] x Mft.}

   = 3600/ {[(20 + 26)/2] x 1.5}

   = 104.34 m.

Consider clear cover 20 mm and 10 mm dia. Of bar is main bar and 8 mm dia. as secondary bars.

D = 104.34 + 20 + 10/2

    = 129.34 mm.

Provide D = 130 mm.

d = 130 – 20 – 10/2

    = 105 mm

dx = 130 – 20 – 10/2

     = 105 mm.

dy = 130 – 20 – 8/2

     = 101 mm.

  1. Calculation of loads:

  1. Self-weight of slab = 0.130 x 25

                                   = 3.25 kN/m2.

  1. Imposed load = 2 kN/m2.

Total working load = 5.25 kN/m2.

Total limit load = 1.5 x 5.25

                             = 7.875 kN/m2.

Consider per mt. width

∴ Total limit load ≈ 8 kN/m

  1. Calculation of bending moment and shear force:

Ly/Lx = 6.1/3.6

= 1.69 < 2……… (Case 7) Page 91, Table 26, IS - 456-2000

-αx = 0.0867

+αx = 0.066

-αy = – (0)

+αy = 0.043

-Mx = (-αx) x (w) x (Lx)2

        = 0.0867 x 8 x 32

         = 6.24 kN-m.

+Mx = (+αx) x (w) x (Lx)2

         = 0.066 x 8 x 32

               = 4.752 kN-m.

-My = 0

+Mx = (+αy) x (w) x (Lx)2

             = 0.043 x 8 x 32

         = 3.096 kN-m.

In case of two-way slab,

Max. S.F. = (wLx)/3

                  = (8 x 3)/3

                   = 8 kN.

  1. Check for flexure:

Mu = 6.24 kN-m.

M.R. for S.R.B.S. = 0.138 x fck x b x d2

6.24 x 106 = 0.138 x 20 x 1000 x d2

d = 47.54 > dprov.

Hence, Safe.

  1. Calculation of Reinforcement:

Description

Short Span

Long Span

Mid Span

Support

Mid Span

Support

B.M. (kN-m)

6.24

4.752

3.096

           –

Effective depth (d) (mm)

105

105

105

105

Ast req. (mm2)

170.42

128.68

83.071

           –

Ast min. (mm2)

126

126

126

           –

Dia. of bar (mm)

10

10

8

           –

Spacingreq. (mm)

460.86

610.34

398.93

           –

Max. Spacing (mm)

3d or 300

3d or 300

3d or 300

           –

Reinf.prov.

10 mm ϕ @ 300 mm c/c

10 mm ϕ @ 300 mm c/c

8 mm ϕ @ 300 mm c/c

           –

Ast prov. (mm2)

261.79

261.79

167.55

           –

Pt. (%)=

Ast x 100/(b x d)

0.24

0.24

0.15

           –

                              Table no. 5. Reinforcement calculation in slab.

Note:

If spacing in short span is greater than long span, then we should keep uniform spacing in all the direction (i.e., the least of values).

  1. Calculation of edge reinforcement (long span):

Ast min. = 0.12% x b x D

            = 762.5 mm2.

Using 8 mm ϕ bars.

Provide no. of bars = 2.

Max. spacing 5 x d or 450

Provide 8 mm ϕ @ 450 mm c/c.

  1. Torsional reinforcement:

Conditions:

Ast] T max. = 3/4 x [(+ve Ast) max. req.]

                     Along shorter span.

Ast] T = 0.5 x Ast] T max.

It will be zero.

Ast] T = 0.

This torsional reinforcement should be provided in both the direction at top and bottom of corner upto a distance of Lx/5……… Page 90, IS - 456-2000.

Torsional reinforcement at bottom corners:

Ast] T max. = 3/4 x [(+ve Ast) max. req.]

Ast] T max. = 3/4 x (170.42)

                   = 127.84 mm2.

Using 8 mm ϕ bars.

Provide no. of bars = 3.

Provide 3 – 8 mm ϕ in both directions at top and bottom of corners.

Torsional reinforcement at bottom corners:

Ast] T = 0.5 x Ast] T max.

        = 0.5 x 127.84

        63.92 mm2

Using 8 mm ϕ bars.

No. of bars = 63.92/[(π/4) x 82]

                     = 1.27 ≈ 3 bars.

  1. Check for Shear:

Vu = 8 kN

Ʈv = Vu/ (b x dx)

    = (8 x 103)/ (1000 x 105)

    = 0.076.

From IS – code 456, page no. 73, table no. 19

Corresponding pt. (%) = 0.24%

D = 130 mm, K = 1.3

  1. Check for Deflection:

Fs = 0.58 x fy x (Ast req/ Ast prov.)

    = 0.58 x 415 x (170.42/261.79)

    = 156.69 N/mm2 

From IS – code 456, page no. 38, fig. 4,

M.F. = 2

d = Leff/ {[(20 + 26)/2] x Mft.}

   = 3100/ {[(20 + 26)/2] x 2}

   = 67.391 mm < dprov.

Hence, Safe.

4.10 DESIGN CRITERIA FOR BEAM:

Tension reinforcement

Minimum reinforcement –

As/bd= 0.85/fy

Where

AS =minimum area of tension reinforcement

b =breadth of beam or the breadth of the web

d =effective depth of beam

fy =characteristic strength of reinforcement in N/mm2

Maximum reinforcement –

The maximum area of tension reinforcement does not to exceed 0.04bD.

Maximum spacing of shear reinforcement (Clause26.5.1.5) 

B E A M  N O.    4714   D E S I G N  R E S U L T S

M25                    Fe415 (Main)               Fe415 (Sec.)

LENGTH:  4100.0 mm      SIZE:   230.0 mm X  600.0 mm   COVER: 25.0 mm

SUMMARY OF REINF. AREA (Sq.mm)

----------------------------------------------------------------------------

SECTION      0.0 mm     1025.0 mm     2050.0 mm     3075.0 mm     4100.0 mm

----------------------------------------------------------------------------

TOP           0.00          0.00          0.00        362.77       1212.26

REINF.      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)

BOTTOM      1192.76        267.10        267.10          0.00          0.00

REINF.      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)

----------------------------------------------------------------------------

SUMMARY OF PROVIDED REINF. AREA

----------------------------------------------------------------------------

SECTION      0.0 mm     1025.0 mm     2050.0 mm     3075.0 mm     4100.0 mm

----------------------------------------------------------------------------

TOP       2-20í         2-20í         2-20í         2-20í         4-20í

REINF.   1 layer(s)    1 layer(s)    1 layer(s)    1 layer(s)    1 layer(s)

BOTTOM     6-16í         2-16í         2-16í         2-16í         2-16í

REINF.   2 layer(s)    1 layer(s)    1 layer(s)    1 layer(s)    1 layer(s)

SHEAR   2 legged  8í  2 legged  8í  2 legged  8í  2 legged  8í  2 legged  8í

REINF.  @ 185 mm c/c  @ 185 mm c/c  @ 185 mm c/c  @ 185 mm c/c  @ 185 mm c/c

----------------------------------------------------------------------------

SHEAR DESIGN RESULTS AT DISTANCE d (EFFECTIVE DEPTH) FROM FACE OF THE SUPPORT

-----------------------------------------------------------------------------

SHEAR DESIGN RESULTS AT   765.0 mm AWAY FROM END SUPPORT

VY =  -128.68 MX =     1.29 LD=    3

Provide 2 Legged  8í  @ 185 mm c/c

============================================================================

B E A M  N O.    3747   D E S I G N  R E S U L T S

M25                    Fe415 (Main)               Fe415 (Sec.)

LENGTH:  7165.0 mm      SIZE:   230.0 mm X  600.0 mm   COVER: 25.0 mm

SUMMARY OF REINF. AREA (Sq.mm)

----------------------------------------------------------------------------

SECTION      0.0 mm     1791.3 mm     3582.5 mm     5373.8 mm     7165.0 mm

----------------------------------------------------------------------------

TOP         428.74          0.00          0.00        311.56       1738.75

REINF.      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)

BOTTOM         0.00        308.21        455.86          0.00        223.57

REINF.      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)

----------------------------------------------------------------------------

SUMMARY OF PROVIDED REINF. AREA

----------------------------------------------------------------------------

SECTION      0.0 mm     1791.3 mm     3582.5 mm     5373.8 mm     7165.0 mm

----------------------------------------------------------------------------

TOP       3-16í         2-16í         2-16í         2-16í         9-16í

REINF.   1 layer(s)    1 layer(s)    1 layer(s)    1 layer(s)    2 layer(s)

BOTTOM     4-10í         4-10í         6-10í         4-10í         4-10í

REINF.   1 layer(s)    1 layer(s)    2 layer(s)    1 layer(s)    1 layer(s)

SHEAR   2 legged  8í  2 legged  8í  2 legged  8í  2 legged  8í  2 legged  8í

REINF.  @ 185 mm c/c  @ 185 mm c/c  @ 185 mm c/c  @ 185 mm c/c  @ 185 mm c/c

----------------------------------------------------------------------------

DXF IMPORT OF METRE C.C.DXF                              -- PAGE NO.  661

SHEAR DESIGN RESULTS AT DISTANCE d (EFFECTIVE DEPTH) FROM FACE OF THE SUPPORT

-----------------------------------------------------------------------------

SHEAR DESIGN RESULTS AT   877.8 mm AWAY FROM END SUPPORT

VY =  -127.49 MX =    -8.64 LD=    3

Provide 2 Legged  8í  @ 175 mm c/c

 

4.11 DESIGN OF STAIRCASE:

RCC Dog-legged Staircase design:

In this type of staircase, the succeeding flights rise in opposite directions. The two flights in plan are not separated by a well. A landing is provided corresponding to the level at which the direction of the flight changes.

Procedure for Dog-legged Staircase design

Based on the direction along which a stair slab span, the stairs maybe classified into the following two types.

  1. Stairs spanning horizontally
  2. Stairs spanning vertically

Stairs spanning horizontally

These stairs are supported at each side by walls. Stringer beams or at one side by wall or at the other side by a beam.

Loads

Stairs spanning Longitudinally

In this, stairs spanning longitudinally, the beam is supported ay top and at the bottom of flights.

Loads

For the efficient design of an RCC stair, we have to first analyze the various loads that are going to be imposed on the stair.

The load calculations will help us determine, how much strength is required to carry the load. The strength bearing capacity of a staircase is determined on the amount of steel and concrete used.

The ratio of steel to concrete has to be as per standards. Steel in the staircase will take the tension imposed on it and the concrete takes up the compression.

These are the essential steps that are to be followed for the RCC Stair Design.

DESIGN OF STAIRCASE:

Staircase room size = 4.565 m x 3.23 m.

Floor to Floor Height = 3 m.

Grade of Concrete = M20 (i.e. fck = 20 N/mm2)

Grade of Steel = Fe415 (i.e. fy = 415 N/mm2)

Live Load = 1 kN/m2.

Floor Finish Load = 1 kN/m2.

Riser (R) = 150 mm.

Tread (T) = 250 mm.

  1. General arrangement:

No. of riser = Floor to Floor Height/Riser

                     = 3000/150

                     = 20 nos.

No. of riser each side = 20/2

                                      = 10 nos.

No. of tread each side = No. of Riser – 1

                                        = 10 – 1

                                        = 9 nos.

Space occupied by tread = No. of tread x Tread length

                                             

                                             = 250 x 9

                                             = 2250 mm.

Width of Landing = (3230 – 2250)/2

                                = 490 mm.

Effective length for flight AB (Leff) = 490 + 2250

                                                            = 2740 mm.

Effective length for flight CD (Leff) = 490 + 2250 + 490

                                                              = 3230 mm.

  1. Design of flight AB:

  1. Depth of slab = Length of flight AB/Density of concrete

                                       = 2740/25

                                       = 109.6 mm. ≈ 120 mm.

              Effective (d) = D – Cover – ϕ/2

                                     = 120 – 20 – 12/2

             

                                     = 94 mm ≈ 100 mm.

  1. Calculation of Loads:

  1. On flight:

Self-weight of waist slab = 25 x D x (R2 + T2 )1/2 /T

                                             = 25 x 0.12 x (0.152 + 0.252 )1/2 /0.25

                               

                                             = 5 kN/m2 ......... (1)

Weight of step = 1/2 x R x Density of concrete

 

                            = 1/2 x 0.15 x 25

                            = 1.875 kN/m2……… (2)

Floor Finish Load = 1 kN/m……… (3)

Live Load = 1 kN/m2……… (4)

Total Load = (1) + (2) + (3) + (4)

                    = 5 + 1.875 + 1 + 1

                    = 8.875 kN/m2

Ultimate Load = 1.5 x 8.875

                   Wu = 13.31 kN/m2

  1. On landing:

Self-weight of slab = Density of concrete x D

                                  = 25 x 0.12

                                  = 3 kN/m……… (5)

Floor Finish Load = 1 kN/m……. (6)

Live Load = 1 kN/m2……. (7)

Total Load = (5) + (6) + (7)

                    = 3 + 1 + 1

                    = 5 kN/m2

Factored Load = 1.5 x 5

                           = 7.5 kN/m2

  1. Bending Moment and Shear Force Calculation:

B.M. = (Wu x L2)/8

          = (13.31 x 2.742)/8

          = 12.05 kN-m

S.F. = (Wu x L)/2

       = (12.05 x 2.74)/2

       = 17.97 kN

  1. Check for Flexure:

d2 = Mu/ (0.138 x fck x b)

d2 = (12.05 x 106)/ (0.138 x 25 x 1000)

    = 59 ≈ 70 mm. < 100 mm.

Hence, Safe.

  1. Calculation of Main Reinforcement:

Mu = 12.05 x 106

Ast req = [(0.5 x fck x b x d)/fy] x {1 – [1 – (4.6 x Mu)/ (fck x b x d2)]1/2}

      = [(0.5 x 25 x 1000 x 100)/415 x {1 – [1 – (4.6 x 12.05 x 106)/ (25 x 1000 x 1002)]1/2}

      = 355 mm2

Ast min. = 0.12% x b x D

           = (0.12/100) x 1000x 120

            = 144 mm2

Provide 10 mm ϕ bars

No. of Bars = Ast req/(π/4) x 102

                                = 355/(π/4) x 102

                                = 5 Nos.

  1. Spacing:

  1. = [(π/4) x ϕ2] x 1000 / Ast req

= [(π/4) x 102] x 1000 / 355

= 220 mm

  1. ≯ 3 x d

≯ 3 x 100 ≯ 300 mm

        

  1. 300 mm

Least values from above 3 values will be the spacing.

spacing = 220 mm c/c

∴ provide 10 mm ϕ bars @ 220 mm c/c

  1. Calculation of Secondary Reinforcement:

Ast = 0.15% x b x D

      = (0.15/100) x 1000x 120

      = 144 mm

∴ provide 10 mm ϕ bars

  1. Spacing:

  1. = [(π/4) x ϕ2] x 1000 / Ast req

= [(π/4) x 82] x 1000 / 144

= 350 mm

  1. ≯ 3 x d

≯ 3 x 100 ≯ 300 mm

        

  1. 450 mm

Least values from above 3 values will be the spacing.

spacing = 350 mm c/c

∴ provide 8 mm ϕ bars @ 350 mm c/c

  1. Check for Shear:

Ʈv = Vu/ (b x d)

    = (17.97 x 103)/ (1000 x 100)

    = 0.179 Mpa

Ast prov. = [(π/4) x ϕ2] x 1000 / Spacing

            = [(π/4) x 102] x 1000 / 220

            = 360 mm2

Pt. (%) = Ast prov. x 100/ (b x d)

             = (360 x 100)/ (1000 x 100)

             = 0.36%

From IS – code 456, page no. 73, table no. 19

By Interpolation,

Ʈc = 0.42 Mpa

From IS – code 456, page no. 72,

K = 1.30

K x Ʈc = 1.30 x 0.42

          = 0.546 N/mm2 

Ʈv < k x Ʈc

0.179 < 0.546

Hence, Safe.

  1. Check for Deflection:

Fs = 0.58 x fy x (Ast req/ Ast prov.)

    = 0.58 x 415 x (355/360)

    = 237 N/mm2 

From IS – code 456, page no. 38, fig. 4,

M.F. = 1.6

d = Leff/ (20x M.F.)

   = 2740/ (1.6 x 20)

   = 85 < 100

Hence, Safe.

Length of each type of bar on either side of crossing should be at least,

Ld = 47 x ϕ

     = 47 x 10

     = 470 mm

  1. Design of flight CD:

  1. Depth of slab = Length of flight CD/Density of concrete

                                       = 2740/25

                                       = 109.6 mm. ≈ 120 mm.

              Effective (d) = D – Cover – ϕ/2

                                     = 120 – 20 – 12/2

             

                                     = 94 mm ≈ 100 mm.

  1. Calculation of Loads:

  1. On flight:

Self-weight of waist slab = 25 x D x (R2 + T2 )1/2 /T

                                             = 25 x 0.12 x (0.152 + 0.252 )1/2 /0.25

                                             = 5 kN/m2 ......... (1)

Weight of step = 1/2 x R x Density of concrete

 

                            = 1/2 x 0.15 x 25

                            = 1.875 kN/m2……… (2)

Floor Finish Load = 1 kN/m……… (3)

Live Load = 1 kN/m2……… (4)

Total Load = (1) + (2) + (3) + (4)

                    = 5 + 1.875 + 1 + 1

                    = 8.875 kN/m2

Ultimate Load = 1.5 x 8.875

                   Wu = 13.31 kN/m2

  1. On landing:

Self-weight of slab = Density of concrete x D

                                  = 25 x 0.12

                                  = 3 kN/m……… (5)

Floor Finish Load = 1 kN/m……. (6)

Live Load = 1 kN/m2……. (7)

Total Load = (5) + (6) + (7)

                    = 3 + 1 + 1

                    = 5 kN/m2

Factored Load = 1.5 x 5

                          = 7.5 kN/m2

  1. Bending Moment and Shear Force Calculation:

B.M. = (Wu x L2)/8

          = (13.31 x 3.232)/8

          = 16.62 kN-m

S.F. = (Wu x L)/2

       = (12.05 x 3.23)/2

       = 18.65 kN

  1. Check for Flexure:

d2 = Mu/ (0.138 x fck x b)

d2 = (16.62 x 106)/ (0.138 x 25 x 1000)

    = 69.49 ≈ 70 mm. < 100 mm.

    Hence, Safe.

  1. Calculation of Main Reinforcement:

Mu = 16.62 x 106

Ast req = [(0.5 x fck x b x d)/fy] x {1 – [1 – (4.6 x Mu)/ (fck x b x d2)]1/2}

      = [(0.5 x 25 x 1000 x 100)/415 x {1 – [1 – (4.6 x 16.62 x 106)/ (25 x 1000 x 1002)]1/2}

      = 500 mm2

Ast min. = 0.12% x b x D

           = (0.12/100) x 1000x 120

           = 144 mm2

Provide 10 mm ϕ bars

No. of Bars = Ast req/(π/4) x 102

                                = 500/(π/4) x 102

                                = 7 Nos.

  1. Spacing:

  1. = [(π/4) x ϕ2] x 1000 / Ast req

= [(π/4) x 102] x 1000 / 500

= 155 mm

  1. ≯ 3 x d

≯ 3 x 100 ≯ 300 mm

        

  1. 300 mm

Least values from above 3 values will be the spacing.

spacing = 150 mm c/c

∴ provide 10 mm ϕ bars @ 150 mm c/c

  1. Calculation of Secondary Reinforcement:

Ast = 0.12% x b x D

      = (0.12/100) x 1000x 120

      = 144 mm

∴ provide 8 mm ϕ bars

  1. Spacing:

  1. = [(π/4) x ϕ2] x 1000 / Ast req

= [(π/4) x 82] x 1000 / 144

= 350 mm

  1. ≯ 5 x d

≯ 5 x 100 ≯ 500 mm

        

  1. 450 mm

Least values from above 3 values will be the spacing.

spacing = 350 mm c/c

∴ provide 8 mm ϕ bars @ 350 mm c/c

  1. Check for Shear:

Ʈv = Vu/ (b x d)

    = (18.65 x 103)/ (1000 x 100)

    = 0.186 Mpa

Ast prov. = [(π/4) x ϕ2] x 1000 / Spacing

            = [(π/4) x 102] x 1000 / 155

            = 510 mm2

Pt. (%) = Ast prov. x 100/ (b x d)

             = (510 x 100)/ (1000 x 100)

             = 0.51%

From IS – code 456, page no. 73, table no. 19

By Interpolation,

Ʈc = 0.46 Mpa

From IS – code 456, page no. 72,

K = 1.30

K x Ʈc = 1.30 x 0.46

        = 0.606 N/mm2 

Ʈv < k x Ʈc

0.18 < 0.606

Hence, Safe.

  1. Check for Deflection:

Fs = 0.58 x fy x (Ast req/ Ast prov.)

    = 0.58 x 415 x (500/510)

    = 240 N/mm2 

From IS – code 456, page no. 38, fig. 4,

M.F. = 1.6

d = Leff/ (20x M.F.)

   = 3230/ (1.6 x 20)

   = 95 < 100

Hence, Safe.

Length of each type of bar on either side of crossing should be at least,

Ld = 47 x ϕ

     = 47 x 10

     = 470 mm

PAD FOOTING:

                                               Fig 12. Analytical plan of pad footing.

COMBINED FOOTING:

                                          Fig 13. Analytical plan of combined footing.

DESIGN AND DETAILINGS OF FOOTINGS:

                                     Fig 14. Schedule of both footings.

ABSOLUTE LOADING:

                                      Fig 15. Absolute loading on the designed structure.

BENDING MOMENT:

                                      Fig 16. Bending moment on the designed structure.

STRESSES IN BEAMS:

                                  Fig 17. Stresses on the beam on the designed structure.

CHAPTER 5

ESTIMATION

There are several kinds of estimating techniques; these can be grouped into two main categories:

  1. Approximate Estimate.
  2. Detailed Estimate.

5.1 APPROXIMATE ESTIMATE:

An approximate estimate is an approximate or rough estimate prepared to obtain an approximate cost in a short time. For certain purposes the use of such methods is justified.

         Approximate estimation for (G+4) Hostel building based on built-up area

Sr. No

Description

Qty. per sq. m

Total built-up(sq. m)

Total quantities

Unit

1

Cement

 

 

 

 

 

(i) R.C.C. work

2.04

4273.82

8718.59

bags

 

(ii) Masonary wall

0.86

4273.82

3675.49

bags

 

(iii) Plaster wall

1.61

4273.82

6880.85

bags

 

(iv) Other works

0.33

4273.82

1410.36

bags

 

 

 

Total

20685.29

bags

2

Sand

 

 

(i) R.C.C. work

0.22

4273.82

940.2404

cum

 

(ii) Masonary wall

0.11

4273.82

470.1202

cum

 

(iii) Internal plaster wall

0.3

4273.82

1282.146

cum

 

(iv) External plaster wall

0.2

4273.82

854.764

cum

 

(v) Tiles

0.04

4273.82

170.9528

cum

 

(vi) Other

0.01

4273.82

42.7382

cum

 

 

 

Total

3760.962

cum

3

Aggregate

0.27

4273.82

1153.931

cum

4

Rubble(soling)

0.06

4273.82

256.4292

cum

5

Murum filling

0.23

4273.82

982.9786

cum

 

 

 

 

 

 

6

Steel

 

 

 

 

 

Footing

0.55

4273.82

2350.6

kg

 

Column up to plinth

2.15

4273.82

9188.71

kg

 

Plinth beam

1.15

4273.82

4914.89

kg

 

Column

4.8

4273.82

20514.34

kg

 

Slab

7

4273.82

29916.74

kg

 

Beam

7.5

4273.82

32053.65

kg

 

Chajja

0.55

4273.82

2350.6

kg

 

O.H.T

0.55

4273.82

2350.6

kg

 

 

 

Total

103640.1

kg

 

 

 

 

 

 

7

Bricks

 

 

 

 

 

Plinth work

 

4273.82

0

Nos.

 

External walls

86

4273.82

367548.5

Nos.

 

Internal walls

43

4273.82

183774.3

Nos.

 

 

 

Total

551322.8

Nos.

8

Aluminum window frame

0.14

4273.82

598.33

Sq. m

 

 

 

 

 

 

9

Glass for window

0.14

4273.82

598.33

Sq. m

10

Skirting

0.82

4273.82

3504.53

r. m

11

TILES

 

 

 

 

 

White & colored glazed dado(including flooring)

0.2

309.28

61.86

Sq. m

12

Floor tiles

0.75

3964.54

2973.41

Sq. m

13

Stair case

 

 

 

 

 

Riser

0.014

4273.82

59.83

Sq. m

 

Tread

0.028

4273.82

119.67

Sq. m

 

Landing

0.022

4273.82

94.02

Sq. m

 

 

Total

273.52

Sq. m

14

Water proofing

 

 

 

 

 

Brick bats

0.09

4273.82

384.64

cum

 

Cement

0.5

879.74

439.87

bags

 

Sand

0.14

879.74

123.16

cum

 

Lime(30 kg/bags)

0.13

879.74

114.37

bags

 

Kavadi(china chips)

13.5

879.74

11876.49

Kg

 

White cement

2.7

879.74

2375.3

Kg

 

 

 

 

 

 

15

Concrete grill(Stair case)

0.03

4273.82

128.21

Sq. m

                                     Table no. 6. Approximate estimate of hostel building.

  1. DETAILED ESTIMATE:

A detailed estimate of the cost of a project is prepared by determining the quantities and costs of everything that a contractor is required to provide and do for the satisfactory completion of the work. It is the best and most reliable form of estimate. A detailed estimate may be prepared in the following two ways:

  1. Unit Quantity Method
  2. Total Quantity Method

  1. UNIT QUANTITY METHOD:

In the unit quantity method, the work is divided into as many operations or items as are required. A unit of measurement is decided. The total quantity of work under each item is taken out in the proper unit of measurement. The total cost per unit quantity of each item is analyzed and worked out. Then the total cost for the item is found by multiplying the cost per unit quantity by the number of units.

For example, while estimating the cost of a building work, the quantity of brickwork in the building would be measured in cubic meters. The total cost (which includes cost of materials. labor, plant, overheads and profit) per cubic meter of brickwork would be found and then this unit cost multiplied by the number of cubic meters of brickwork in the building would give the estimated cost of brickwork. This method has the advantage that the unit costs on various jobs can be readily compared and that the total estimate can easily be corrected for variations in quantities.

  1. TOTAL QUANTITY METHOD:

In the total quantity method, an item of work is divided into the following five subdivisions:

  1. Materials.
  2. Labor.
  3. Plant.
  4. Overheads.
  5. Profit

The total quantities of each kind or class of material or labor are found and multiplied by their individual unit cost. Similarly, the cost of plant, overhead expenses and profit are determined.

                                               Table no. 7. Detailed estimate of steel

                                     Table no. 8. Overall steel required for the structure.

Table no. 9. Detailed estimate of concrete in structure.

CHAPTER 6

CONCLUSION AND REFERENCES

6.1 CONCLUSIONS:

We can conclude that there is difference between the theoretical and practical work done. As the scope of understanding will be much more when practical work is done. As we get more knowledge in such a situation where we have great experience doing the practical work.

Knowing about the softwares we studied earlier, we have drawn plan of different floors using AutoCAD. We gained much more knowledge and now it becomes handier to use. All other designing and estimating are done by using proper references like IS code and authorised books by well-known authors.

We also learned working in team and till now we have put all our efforts doing the project and we will continue to give all our efforts in our future work.

6.2 REFERENCES:

6.2.1 REFERENCE CODES FOR PROJECT:

Sr. No

Codes

Code detail

1

IS 1893 (part-1): 2002

Criteria for earthquake resistance Design of Structure.

2

IS 875 (part-1): 1987

Code of Practice for Design loads (other  than Earthquake) for Buildings and Structures (Dead loads – Unit  weights of  building materials and stored materials)

3

IS 875 (part-2): 1987

Code of Practice for Design loads (other than Earthquake) for Buildings and Structures (Imposed load)

4

IS 875 (part-3): 1987

Code of Practice for Design loads (other than Earthquake) for Buildings and Structures (wind load).

5

IS 875 (Part-4): 1987

Code of Practice for Design loads (other than Earthquake) for Buildings and Structures (Snow load)

6

IS 13920: 1993

Ductile detailing of reinforced concrete structures subjected to seismic force.

7

IS 800: 2007

Code of Practice for general Construction in steel.

8

IS 3370: 1982

Code of practice for concrete structure for the storage of liquids.

                                                 Table no. 10. IS codes.

6.2.2 REFERENCE BOOKS FOR PROJECT:

1. A.K. Jain, Advanced R.C.C. Design.

2. VN Vazirani Civil Engineering Estimating, Costing & Valuation.

3. Sandeep Mantri – The A to Z of Practical Building Construction and its Management.                                 

4. N. Krishna Raju, Reinforced Concrete Design.

5. S.S. Bhavikatti, Advanced R.C.C. Design.

6.2.3 REFERENCE WEBSITES FOR PROJECT:

1. https://aboutcivil.org

2. https://thesis123.com

3.https://1000projects.org

4. https://mycadsite.com/tutorials/

5. http://www.yourhome.gov.au/

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