Design and Analysis of Residential Buildingijirt.org/master/publishedpaper/IJIRT148642_PAPER.pdf ·...

© September 2019 | IJIRT | Volume 6 Issue 4 | ISSN: 2349-6002

IJIRT 148642 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 179

Design and Analysis of Residential Building

Faisal Mehraj Wani1, Tamseel Ahmad Bhat

2, Khair Ul Faisal Wani

3, Danish Zahoor

4

1,3M.Tech. Student, Structural Engineering, Jain University, Bengaluru

2,4B.Tech. Student, Civil Engineering, Jain University

Abstract- Manual design of multistory building is

becoming obsolete day by day due to invent of new

software’s like ETABS, STAAD PRO. This software

save energy, time, provide exact and provide precise

results. Etabs offer a single user interface to perform:

Modeling, Analysis, Design and Detailing. We have

adopted limit state method of analysis. The design is in

confirmation with IS 456-2000.

In this project we are analyzing (G+3) residential 2

BHK flat by using Etabs. —ETABS stands for

Extended Three dimensional Analysis of Building

Systems. The modeling of structure is done in rivet and

a realistic 3d image of structure is obtained. Design of

beam, column is done by Etabs. Staad foundation is

used for designing of footing and spread sheet for

designing of slabs. Post analysis of the structure,

maximum shear forces, bending moments, and

maximum storey displacement are computed.

Index terms- Boiler Etabs, Staad foundation

1. INTRODUCTION

Structural design is the primary aspect of civil

engineering. Structural analysis means determination

of the general shape and all the specific dimensions

of a particular structure so that it will perform the

function for which it is created and will safely

withstand the influences which will act on it

throughout its useful life. The foremost basic in

structure is the design of simple basic components

and members of a building like slabs, beams,

columns, and footings. In order to design them it is

important to first obtain the plan of the particular

building. Thereby depending on the suitability plan

layout of beams and the position of columns are

fixed. Thereafter, the vertical loads are calculated

namely the dead load and live load. Once the loads

are obtained, the component takes the load first i.e.

the slabs can be designed. Designing of slabs depends

upon whether it is a one-way or a two-way slab, the

end condition and the loading. From the slabs, the

loads are transferred to the beam. The loads coming

from the slabs onto the beam may be trapezoidal or

triangular. Depending on this, the beam may be

designed. Thereafter, the loads (mainly shear) from

the beams are taken by the columns. For designing

columns, it is necessary to know the moments they

are subjected to for this purpose; frame analysis is

done by Kanis method. After this the designing of

column is taken up depending on end conditions,

moments, eccentricity and if it is a short or slender

column. Finally, the footings are designed based on

the loading from the column and also the soil bearing

capacity value for that` particular area. Most

importantly, the sections must be checked for all the

components with regard to strength and

serviceability.

1.1 OBJECTIVE

Following are the objectives

1. Modeling the building using the software

ETABS 2016

2. Applying gravity loads and different load

combinations as per Indian codal provision.

3. Analyzing and designing of residential building

for worst case of load combination.

4. Design of footing using STAAD foundation.

1.2 PLAN OF RESIDENTIAL BUILDING

The residential building 2bhk flat is taken for

analyzing and designing. The architect plan was

modeled in Revit and a realistic 3d image of structure

is obtained. Placements of column were done keeping

in mind the orientation and the distance between the

columns. After placement of column the beams were

run parallel to columns to form structure layout.



Fig 1.1 Plan of residential building

Fig 1.2 3D of residential building using Revit

software

2. MODELLING OF RCC FRAMES

An RCC framed structure is basically an assembly of

slabs, beams, columns and foundation inter-

connected to each other as a unit. The load transfer

mechanism in these structures is from slabs to beams,

from beams to columns, and then ultimately from

columns to the foundation, which in turn passes the

load to the soil. In this structural analysis study, we

have adopted a regular geometry with dimension

11.09x12.25M. A floor to floor height of 3m is

assumed. Structural Plan of the building is shown in

the following figure.

Fig 2.1 Structure layout of residential building

Table 1 Building Description

Length x Width 12.25x11.09m

No. of storeys 4

Height of similar storey 3m

Height of parapet wall 1m

Thickness of outer wall 230mm

Thickness of inner wall 125mm

Beam dimension 230x450mm

Column dimension 250x450mm

Table 2 material specification

Grade of concrete,M25 fck= 25N/mm2

Grade of steel fy= 415N/mm2

Density of brick ϒbrick= 20kN/m

Density of concrete ϒc= 25kN/m

2.1 LOADING

Loads acting on the structure are dead load (DL),

Live load and Earthquake load (EL).

1. Dead load: Wall load, Parapet load and floor load

(IS 875(Part1))

The dimensions of the cross section are to be

assumed initially which enable to estimate the dead

load from the known weights of the structure. The

values of the unit weights of the structure and the

values of the unit weight of the materials are

specified in IS 875:1987(Part-I). As per IS 875: 1987



(part I). The dead load assigned in the ground floor is

shown in the figure 3.

Unit weight of brick = 20 kN/m 3

Unit weight of concrete = 25kN/m

a) Wall load= (unit weight of brick masonry X wall

thickness X wall height)

= 20 kN/m3 X 0.230m X (3-0.45) m = 11.73

kN/m (acting on outer beam)

= 20 kN/m3 X 0.125m X (3-0.45) m = 6.375

kN/m (acting on inner beam)

b) Wall load (due to Parapet wall at top floor) =

(unit weight of brick masonry X parapet wall

thickness X wall height) = 20 kN/m3 X 0.125m

X 1m= 2.5 kN/m

Fig 2.1 Details of wall load on frames

2. Live load:

They are also known as imposed loads and consist of

all loads other than the dead loads of the structure.

The standard values are stipulated in IS875:1987

(part II).The live loads considered are given in table.

The assigned live load on ground floor in Etabs will

be as shown in the figure. Live load: 2kN/m2 (acting

on slab)

Table 3 live loads (IS875:1987 (part II)

Area Live load ( kN/m2 )

All rooms and kitchens 2

Toilet and bathrooms 2

Corridors, Passages,

Staircases

3

Balconies 3

Parking 5

Electrical Room 5

Machine room 5

Fig 2.2 Details of live load on shells

3. Floor finish: 1 kN/m

Fig 2.3 Details of floor finish on shells

4. Seismic Load:

Earthquakes generate waves which move from the

origin of its location with velocities depending on the



intensity and magnitude of the earthquake. The

impact of earthquake on the structures depends on the

stiffness of the structure, stiffness of the soil media,

height and location of the structure, etc. the

earthquake forces are prescribed in IS 1893:2002

(part-I).

Seismic zone: V (Z=0.36), Soil type: I, Importance

factor: 1, Response reduction factor: 5, Damping:

5%. IS 1893(Part-1):2002

Here Seismic load is considered along two directions

EQlength and EQwidth.

2.2 LOAD COMBINATION

The structure should be analyzed for different load

combination as different types of loads are acting on

a structure throughout the life of structure. The

different types of loads on the building are

1. Dead load

2. Live load

3. Eq X

4. EQ Y

The beams, column and slab are designed for

factored load combination whereas footings are to be

designed for factored load combination. Geotechnical

engineer has already taken factor of safety into

account while determining the safe bearing capacity

(SBC) of soil.

3. ANALYSIS

Fig 3.1 Displacement of joints

It can be seen that the displacement increase while

going up as the fixity of column decreases as we go

up as there is no floor on the top. The displacement at

top floor is minimum.

Fig 3.2 Bending moment diagram

Colorful image of bending moment is obtained from

software. The BM at the ends are hogging which

means reinforcement is to be provided at the top

while in the middle portion BM is sagging, the

reinforcement provided at bottom. The BM at the

Centre is maximum as we go up due to decreases in

fixity of joints.

Fig 3.3 Axial force diagram



Fig 3.4 Details of axial force due to seismic load

The axial force for the bottom stories is more than the

top stories. Structures experiencing earthquake

forces, axial force for external column is high while

internal column experience less force as shown in

above figure.

4. CONCRETE FRAME DESIGN

The design methods used for the design of reinforced

concrete structures are working stress method,

ultimate load method and limit state method. Here we

have adopted the limit state method of design for

slabs, beams, columns and stairs. In the limit state

method, the structure is designed to withstand safely

all loads liable to act on it through its life and also to

satisfy the serviceability requirements, such as

limitation to deflection and cracking. After the

analysis and interpretation of result, the concrete

frame design is carried out by selecting the design

load combination. The structural member (column

and beam) is said to be failed if it is shown in red

color. The minimum reinforcement of columns

should be 0.8% of cross section and maximum should

be 6% of cross section but practically 4% of cross

section is taken into consideration. The minimum

reinforcement in beams should be 0.4bd and

maximum of 4% of cross section. All the structural

members passed the design check in this project as

shown in figure.

Fig 4.1 concrete frame design

Fig 4.2 check for concrete frame design

5. DETAILING

The final step after designing is to generate rebar

tables for structural members. The detailing process

helps us to generate drawing sheets, floor plans,

reinforcement cage view etc.



Table 4 concrete beam rebar table

6. DESIGN OF SLAB

The slabs were designed using spread sheet in which

length and width were used to check the minimum

required thickness and reinforcement of slab. The

minimum thickness was takes as 125mm for whole

structure. The minimum steel for slab should be

0.12%of c/s area of slab.

Fig 6.1 Spread sheet for designing of slab

7. DESIGN OF FOUNDATION

The footings were designed using staad foundation.

The FZ forces were imported to staad foundation to

design all footing at once. The footing should be

designed as isolated in the beginning; if the footings

are overlapping then we should design for combined

footing. The SBC of soil was taken as 150kpa and the

depth of soil above footing as 2000mm.In this project

we are designing isolated footing as the exaction plan

does not coincide. The different sizes of footing were

obtained from the software.

Fig 7.1 Excavation plan for residential building

Table 5 Details of size of footing

8. CONCLUSION



1. This project has given an opportunity to re-

collect and co-ordinate the various methods of

designing and engineering principles which we

have learnt in our lower classes.

2. Analysis was done by using ETABS software

and successfully verified manually as per IS456.

3. Calculation by both manual work as well as

software analysis gives almost same result.

4. Shear force and bending moment increases for

both beams and columns as the storey height

Increases.

5. Design of isolated footing was done

successfully.

REFERENCES

[1] IS: 456-2000, Code of Practice Plain and

Reinforced Concrete.

[2] IS: 875-1987 (Part 1) – 1987, Code of practice

for design loads (other than earthquake) for

buildings and structures.

[3] IS: 875-1987 (Part 1) – 1987, Code of practice

for design loads (other than earthquake) for

buildings and structures – Imposed loads.

[4] Mohd atif et [al] “comparative study on seismic

analysis of multistory building stiffened with

bracing and shear wall”, IRJET – 2015.

[5] Syed khasim mutwallie et [al] “Dynamic

response of high rise structure under the

influence of shear walls”. Int. Journal of

engineering research and applications. ISSN:

22248-9622, vol 4.

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