KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
COMPARATIVE STUDY ON DESIGN RESULTS OF A MULTI-STORIED
BUILDING USING STAAD PRO AND ETABS FOR REGULAR AND
IRREGULAR PLAN CONFIGURATION
PASUPULAETI KALYANI 1*, B BEERAIAH 2*
1. II. M.Tech , Dept of CIVIL, Velaga Nageswararao College of Engineering.
2. Asst. Prof, Dept. of CIVIL, Velaga Nageswararao College of Engineering.
ABSTRACT:
Structural Analysis and design are predominant in finding out significant threats to integrity and stability of
a structure. Multi storied structures, when designed, are made to fulfill basic aspects and serviceability. Since
Robustness of structure depends on loads imposed, it requires attention. All the challenges faced by structural
engineers were taken as opportunities to develop software’s such as STAAD PRO, ETABS & SAFE, SAP etc., with
ease of use. Software such as ETABS and STAAD-pro are leading commercial software’s worldwide for structural
analysis. The design results using STAAD PRO and ETABS of a rectangular RCC building, for both regular and
irregular plan configuration, are obtained and compared. The main purpose of this study is to carry out a detailed
analysis on simulation tools ETABS and STAAD PRO, which have been used for analysis and design of rectangular
Plan with vertical regular and rectangular Plan with Vertical geometrically irregular multi-storey building. This
study is focused on bringing out advantages of using ETABS over current practices of STAAD PRO versions to
light. It was observed that ETABS is more user friendly, accurate, compatible for analysing design results and many
more advantages to be discussed in this study over STAADPRO. Pros and cons of using these software’s will also
be mentioned in this study.
1. INTRODUCTION
Reinforced concrete is a composite material in which
1.1 RCC FRAME STRUCTURES
concrete's relatively low tensile strength and ductility
An RCC framed structure is basically an are counteracted by the inclusion of reinforcement
assembly of slabs, beams, columns and foundation having higher tensile strength and ductility. The
inter -connected to each other as a unit. The load reinforcement is usually embedded passively in the
transfer, in such a structure takes place from the slabs concrete before the concrete sets. The reinforcement
to the beams, from the beams to the columns and then needs to have the following properties at least for the
to the lower columns and finally to the foundation strong and durable construction:
which in turn transfers it to the soil. The floor area of
a R.C.C framed structure building is 10 to 12 percent • High relative strength
more than that of a load bearing walled building. • High toleration of tensile strain
Monolithic construction is possible with R.C.C • Good bond to the concrete, irrespective of
framed structures and they can resist vibrations, pH, moisture, and similar factor.
earthquakes and shocks more effectively than load • Thermal compatibility, not causing
bearing walled buildings. Speed of construction for unacceptable stresses in response to
RCC framed structures is more rapid. changing temperatures.
1.2 OBJECTIVE
1. To check the behaviour of multi-storey regular and
irregular building on software (STAADPro. &
ETABS).
2. To understand the accuracy of softwares for
analysis and design for plan and elevation
Irregularity.
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
3. To compare the results and behaviour of structures However it leads to excessive deformations and
on both the software. cracking. This method is failed to satisfy the
serviceability and durability requirements. To
DIFFERENT METHODS USED FOR DESIGN
overcome these drawbacks, the limit state method has
1. Working stress method been developed to take care of both strength and
2. Limit state method serviceability requirements.
3. Ultimate load method STAADPro Vi8.
Working Stress Method One of the most famous analysis methods
for analysis is “Moment Distribution Method”,
It is based on the elastic theory assumes which is based on the concept of transferring the
reinforced concrete as elastic material. The stress loads on the beams to the supports at their ends. Each
strain curve of concrete is assumed as linear from support will take portion of the load according to its
zero at neutral axis to maximum value at extreme K; K is the stiffness factor, which equals (EI/L). E,
fibre. This method adopts permissible stresses which and L is constant per span, the only variable is I;
are obtained by dividing ultimate stress by factor moment of inertia. I depend on the cross section of
known as factor of safety. For concrete factor of the member. To use the moment distribution method,
safety 3 is used and for steel it is 1.78. This factor of you have to assume a cross section for the spans of
safety accounts for any uncertainties in estimation of the continuous beam. To analyze the frame,
working loads and variation of material properties. In “Stiffness Matrix Method” is used which depends
Working stress method, the structural members are upon matrices. The main formula of this method is
designed for working loads such that the stresses [P] = [K] x [Δ]. [P] is the force matrix = Dead Load,
developed are within the allowable stresses. Hence, Live Load, Wind Load, etc. [K] is the stiffness factor
the failure criterions are the stresses. This method is matrix. K= (EI/L). [Δ] is the displacement matrix.
simple and reasonably reliable. This method has
been deleted in IS 456-2000, but the concept of this STAAD was the first structural software
method is retained for checking the serviceability, which adopted Matrix Methods for analysis. The
states of deflection and cracking. stiffness analysis implemented in STAAD is based on
the matrix displacement method. In the matrix
Limit State Method analysis of structures by the displacement
In this method, the structural elements are method, the structure is first idealized into an
designed for ultimate load and checked for assembly of discrete structural components (frame
serviceability (deflection, cracking etc.) at working members or finite elements). Each component has an
loads so that the structure is fit for use throughout its assumed form of displacement in a manner which
life period. As in working stress method this method satisfies the force equilibrium and displacement
does not assume stress strain curve as linear. This compatibility at the joints.
method gives economical sections. STAAD stands for Structural Analysis and
Ultimate Load Method Design. STAAD.Pro is a general purpose structural
analysis and design program with applications
In this method structural elements are
primarily in the building industry – commercial
designed for ultimate loads which are obtained by
buildings, bridges and highways structures, and
multiplying the working loads with a factor known as
industrial structures etc. The program hence consists
load factor. Hence, the designer can able to predict
of the following facilities to enable this task:-
the excess load the structure can carry beyond the
working loads without collapse. Hence, this method Graphical model generation utilities as well
gives the true margin of safety. This method as text editor based commands for creating the
considers the actual stress strain curve of concrete mathematical model. Beam and column members are
and the failure criteria is assumed as ultimate strain. represented using lines. Walls, slabs and panel type
This method gives very economical sections. entities are represented using triangular and
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
quadrilateral finite elements. Solid blocks are “weak-column strong- beam frame” which is likely to
represented using brick elements. These utilities exhibit poor post yield hysteretic behaviour. The
allow the user to create the geometry, assign building was expected to have maximum lateral
properties, orient cross sections as desired, assign deformation capacities corresponding to about 2%
materials like steel, concrete, timber, aluminium, lateral drift. The unreinforced masonry infill walls
specify supports, apply loads explicitly as well as were likely to begin cracking at much smaller lateral
have the program generate loads, design parameters drifts, of the order of 0.3%, and completely lost their
etc. load carrying ability by drifts of between 1% and 2%.
Analysis engines for performing linear Sanghani and Paresh (2011) studied the
elastic and p-delta analysis, finite element analysis, behaviour of beam and column at various storey
frequency extraction and dynamic response. levels. It was found that the maximum axial force
generated in the ground floor columns, max
Design engines for code checking and
reinforcement required in the second floor beams.
optimization of steel, aluminium and timber
members. Reinforcement calculations for concrete Poonam et al. (2012) Results of the
beams, columns, slabs and shear numerical analysis showed that any storey, especially
the first storey, must not be softer/weaker than the
ETABS
storeys above or below. Irregularity in mass
ETABS stands for Extended Three distribution also contributes to the increased response
dimensional Analysis of Building Systems. ETABS of the buildings. The irregularities, if required to be
was used to create the mathematical model of the provided, need to be provided by
Burj Khalifa, designed by Chicago, Illinois-based appropriate and extensive analysis and design
Skidmore, Owings and Merrill LLP (SOM). ETABS processes.
is commonly used to analyze: Skyscrapers, parking
Prashanth.P et al. (2012) investigated the
garages, steel & concrete structures, low rise
buildings, portal frame structures, and high rise behaviour of regular and irregular multi storey
buildings. The input, output and numerical solution building structure in STAADPro. and ETABS.
Analysis and design was done according to IS-456
techniques of ETABS are specifically designed to
and IS-1893(2002) code. Also manually calculations
take advantage of the unique physical and numerical
were done to compare results. It was found that the
characteristics associated with building type
structures. A complete suite of Windows graphical ETABS gave the lesser steel area as that of
tools and utilities are included with the base package, STAADPro. Loading combinations were not
considered in the analysis and influence of storey
including a modeller and a postprocessor for viewing
height on the structural behaviour was not described.
all results, including force diagrams and deflected
shapes. 3. MODELLING OF RCC FRAMES RCC
FRAME STRUCTURE
2. REVIEW OF LITERATURE
An RCC framed structure is basically an
Most of the work for analysis of multi storey
assembly of slabs, beams, columns and foundation
building has been done on STAADP ro. Evaluation
inter-connected to each other as a unit. The load
of forces and moments for Dead load, Live load
and Seismic load considered. But there is very less transfer, in such a structure takes place from the slabs
to the beams, from the beams to the columns and then
work has been done using load combination.
to the lower columns and finally to the foundation
M C Griffith and A V Pinto (2000) have which in turn transfers it to the soil.
investigated the specific details of a 4-story, 3-bay
General
reinforced concrete frame test structure with
unreinforced brick masonry (URM) infill walls with Case I Regular Building
attention to their weaknesses with regards to seismic
Case II Irregular Building
loading. The concrete frame was shown to be a
Case I: Regular Building
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
A 32m x 20m 12-storey multi storey regular
structure is considered for the study. Size of the each
grid portion is 4m x 4m. Height of each storey is 3m
and total height of the building is 36m. Plan of the
building considered is shown in the figure 3.1
Loading
Loads acting on the structure are dead load (DL),
Live load and Earthquake load (EL), Dead load
consists of Self weight of the structure, Wall load,
Parapet load and floor load.
Live load: 3kN/m2 is considered, Seismic zone: V,
Soil type: II, Response reduction factor: 5,
Importance factor: 1, Damping: 5%. Members are
Case II: Irregular Building loaded with dead load, live load and seismic loads
according to IS code 875(Part1, Part 2) and IS
A 32m X 20m 12-storey multi storey irregular
1893(Part-1):2002.
structure is considered for the study. Size of each grid
portion is 4m x 4m. Plan of the building considered is Self weight
shown in the figure 3.2. Self weight comprises of the weight of beams,
columns and slab of the building.
Dead load
All permanent constructions of the structure form
the dead load. The dead load comprises of the
weights of walls, partition floor finishes, floors and
other permanent constructions in the building. Dead
load consists of:
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
3. RESULTS AND DISCUSSION
Fig-3.3: Regular building
Fig-3.4: Irregular building
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
2. Max Deformation of members of 12-storey regular
and irregular building
As per above table it has been concluded
that the maximum displacement is along x- direction
and its value is 106.25mm (in STAADPro.)
for irregular building and 53.47mm (in ETABS)
along z-direction for regular building. So, more
precise results are generated by ETABS which leads
to economical design of the building.
3. Design Results of sample beam and column
Column C13 of storey 6 from ETABS and Column
851 of storey 6 from STAADPro. Of 12 storey –
CONCLUSION regular building are taken for comparison.
After Discussion of results and observation
some of results are summarized. Based on the
behaviour of RCC frames on STAAD.PRO and
ETABS some important conclusions are drawn
1. Results of max vertical reactions of a 12- storey
regular building. As per table 5.1 it has been
concluded that the max reaction produced is
As per above table it has been
4572.12kN in ETABS and 4624.92kN in
concluded that the ETABS gave lesser area of steel
STAAD.Pro due to load 1.5(Self+Dead+Live).
required as compared to STAADPro. in case of
beam whereas in case of column steel calculated is
same by both softwares.
4. Comparison of Storey Overturning Moments
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
KALYANI P, et al, International Journal of Research Sciences and Advanced
Engineering [IJRSAE]TM. Thomson Reuters Research ID: D-1153-2018, SJI
Listed, Volume 2, Issue 22, PP: 142 - 148, APR - JUN’ 2018.
5) Bureau of Indian Standards: IS-875, part 2 (1987),
Live Loads on Buildings and Structures, New
Delhi, India.
6) Bureau of Indian Standards: IS-1893, part 1
(2002), Criteria for Earthquake Resistant Design
of Structures: Part 1 General provisions and
Buildings, New Delhi, India.
7) Hammad Salahuddin, Saqib Habib, Talha
Rehman (2010), “Comparison of design of a
building using ETABS V 9.5 & STAAD PRO
2005,” University of Engineering and Technology,
As per above graph it has been concluded Taxila, Pakistan
that the storey overturning moment decreases with
increase in storey height along x-direction for
EQlength load and they are more in regular building
than the irregular building.
5. Maximum Steel Reinforcement of beam and
column of regular and irregular building in
ETABS.
As per above table it has been concluded that
the ETABS gave lesser area of steel reinforcement for
irregular building as compared to regular building
in case of beams and columns.
REFERENCE
1) Griffith M. C., Pinto A. V. (2000), “Seismic
Retrofit of RC Buildings - A Review and Case
Study”, University of Adelaide, Adelaide,
Australia and European Commission, Joint
Research Centre, Ispra Italy
2) Sanghani bharat k. and Paresh Girishbhai Patel,
2011, “Behaviour of Building Component in
Various Zones,” International Journal of Advances
in Engineering Sciences, Vol. 1, Issue 1(Jan. 2011)
3) Poonam, Kumar Anil and Gupta Ashok K, 2012,
“Study of Response of Structural Irregular Building
Frames to Seismic Excitations,” International
Journal of Civil, Structural, Environmental and
Infrastructure Engineering Research and
Development (IJCSEIERD), ISSN 2249-6866
Vol.2, Issue 2 (2012) 25-31.
4) Bureau of Indian Standards: IS-875, part 1 (1987),
Dead Loads on Buildings and Structures, New
Delhi, India
International Journal of Research Sciences and Advanced Engineering
Vol.2 (22), ISSN: 2319-6106, APR - JUN’ 2018. PP: 142 - 148
