A study on Structural behavior of high Raised Building for ... · PDF fileModelling of 30- storeys r.c.c. Framed ... low and high rise buildings, ... and steel joist design, ETABS

International Journal On Recent & Innovative Trend In Technology ISSN: 2454-1400

Volume: 1 Issue: 4 August - 2015

www.ijritt.org IJRITTV1IS040025 179

A study on Structural behavior of high

Raised Building for Rectangular Shape

Modelling of 30- storeys r.c.c. Framed

Building

Golakoti. S. Kartheek,

Kakinada Institute of Engineering & Technology,

Korangi, AP, India.

Pappineedi Aruna, Aditya Engineering College,

Surampalem,A.P. India.

G. S. V. Brahamaji Pragati Engineering College,

Surampalem, AP, India.

Abstract: ETABS is the present day leading design software in the market. Many design companies use

this software for their project design purposes. ETABS is commonly used to analyze: Skyscrapers,

parking garages, steel & concrete structures, low and high rise buildings, and portal frame structures.

The case study in this paper mainly emphasizes on structural behavior of high raised building for

different plan configurations like rectangular shape. Modelling of 30- storeys R.C.C. framed building is

done on the ETABS software for analysis. Post analysis of the structure, maximum shear forces, bending

moments, and maximum storey displacement are computed and then compared for all the analyzed cases.

Keywords: Structure Design, STAADPro and ETABS.

1.0 INTRODUCTION ETABS is a sophisticated, yet easy to use, special

purpose analysis and design program developed

specifically for building systems. ETABS features

an intuitive and powerful graphical interface

coupled with unmatched modeling, analytical,

design, and detailing procedures, all integrated

using a common database. Although quick and

easy for simple structures, ETABS can also handle

the largest and most complex building models,

including a wide range of nonlinear behaviors

necessary for Performance based design, making it

the tool of choice for structural engineers in the

building industry.

1.1 What ETABS Can Do!

ETABS offers the widest assortment of analysis

and design tools available for the structural

engineer working on building structures. The

following list represents just a portion of the types

of systems and analyses that ETABS can handle

easily:

Multi-story commercial, government and

health care facilities.

Parking garages with circular and linear ramps.

Buildings with curved beams, walls and floor

edges.

Buildings with steel, concrete, composite or

joist floor framing.

Projects with multiple towers.

Complex shear walls and cores with arbitrary

openings.

Performance based design utilizing nonlinear

dynamic analyses.

Buildings based on multiple rectangular and/or

cylindrical grid systems.

Flat and waffle slab concrete buildings.

Buildings subjected to any number of vertical

and lateral load cases and combinations,

including automated wind and seismic loads.

Multiple response spectrum load cases, with

built-in input curves.

Automated transfer of vertical loads on floors

to beams and walls.




Capacity check of beam-to-column and beam-

to-beam steel connections.

P-Delta analysis with static or dynamic

analysis.

Explicit panel-zone deformations.

Construction sequence loading analysis.

Multiple linear and nonlinear time history load

cases in any direction.

Foundation/support settlement.

Large displacement analyses.

Nonlinear static pushover.

Buildings with base isolators and dampers.

Design optimization for steel and concrete

frames.

Design capacity check of steel column base

plates.

Floor modeling with rigid or semi-rigid

diaphragms.

Automated vertical live load reductions.

1.2 Load Cases

A load case defines how loads are to be applied to

the structure, and how the structural response is to

be calculated. Many types of load cases are

available. Most broadly, load cases are classified as

linear or nonlinear, depending on how the structure

responds to the loading. The results of linear

analyses may be superposed, i.e., added together,

after analysis. The following types of load cases are

available:

Static: The most common type of analysis.

Loads are applied without dynamical effects.

Response-Spectrum: Statistical calculation

of the response caused by acceleration loads.

Requires response-spectrum functions.

Time-History: Time-varying loads are

applied. Requires time history functions. The

solution may be by modal superposition or

direct integration methods.

Buckling: Calculation of buckling modes

under the application of loads. The results of

nonlinear load cases normally should not be

superposed. Instead, all loads acting together

on the structure should be combined directly

within the specific nonlinear load case.

Nonlinear load cases may be chained together

to represent complex loading sequences. The

following types of nonlinear load cases are

available:

Nonlinear Static: Loads are applied without

dynamical effects.

May be used for pushover analysis.

Nonlinear Staged Construction: Loads are

applied without dynamical effects, with

portions of the structure being added or

removed. Time-dependent effects can be

included, such as creep, shrinkage, and aging.

1.3 Load Combinations

ETABS allows for the named combination of the

results from one or more load cases and/or other

combinations. When a combination is defined, it

applies to the results for every object in the model.

The five types of combinations are as follows:

Linear Add: Results from the included load

cases and combinations are added.

Envelope: Results from the included load

cases and combinations are enveloped to find

the maximum and minimum values.

Absolute Add: The absolute values of the

results from the included load cases and

combinations are added.

SRSS: The square root of the sum of the

squares of the results from the included load

cases and combinations is computed.

Range Add: Positive values are added to the

maximum and negative values are added to the

minimum for the included load cases and

combos. Except for the Envelope type,

combinations should usually be applied only to

linear load cases, because nonlinear results are

not generally supposable.

1.4 Design Settings

ETABS offers the following integrated design

postprocessors:

Steel Frame Design

Concrete Frame Design

Composite Beam Design

Composite Column Design

Steel Joist Design

Shear Wall Design

Steel Connection Design

The first five design procedures are applicable to

frame objects, and the program determines the

appropriate design procedure for a frame object

when the analysis is run. The design procedure

selected is based on the line object’s orientation,

section property, material type and connectivity.

Shear wall design is available for objects that have

previously been identified as piers or spandrels,

and both piers and spandrels may consist of both

shell and frame objects. Steel connection design

will identify which beam-to-beam and beam-to

column locations have adequate load transfer

capacity using the standard connections specified

in the connection preferences. Steel connection

design also includes sizing and design capacity

checks for column base plates. For each of the first

five design postprocessors, several settings can be

adjusted to affect the design of the model:




The specific design code to be used for each

type of object, e.g., AISC 360-10 for steel

frames, EUROCODE 2-2004 for concrete

frames, and BS8110 97 for shear walls.

Preferences for how these codes should be

applied to a model.

Combinations for which the design should be

checked.

Groups of objects that should share the same

design.

Optional “overwrite” values for each object

that supersede the default coefficients and

parameters used in the design code formulas

selected by the program. For steel and concrete

frames, composite beam, composite column,

and steel joist design, ETABS can

automatically select an optimum section from

a list you define. The section also can be

changed manually during the design process.

As a result, each frame object can have two

different section properties associated with it:

An “analysis section” used in the previous

analysis

A “design section” resulting from the current

design The design section becomes the

analysis section for the next analysis, and the

iterative analysis and design cycle should be

continued until the two sections become the

same. Design results for the design section,

when available, as well as all of the settings

described herein, can be considered to be part

of the model.

1.5 ETABS Analysis Techniques

This chapter provides an overview of some of the

analysis techniques available within ETABS. The

types of analyses described are P-Delta analysis,

linear static analysis, modal analysis, response-

spectrum analysis, time-history analysis, linear

buckling analysis and nonlinear analysis. In a given

analysis run, you may request a P-Delta analysis,

and multiple cases of linear static, modal, response

spectrum, time history, and buckling analyses.

Multiple nonlinear static and time history analysis

cases may also be defined.

Linear Static Analysis

A linear static load case is automatically created for

each load pattern that is defined. The results of

different load cases can be combined with each

other and with other linear load cases, such as

response spectrum analyses.

Geometric and material nonlinearity, except for the

P-Delta effect, are not considered in a linear static

analysis.

P-Delta Analysis

The P-Delta option accounts for the effect of a

large compressive or tensile load upon the

transverse stiffness of members in the structure.

Compression reduces lateral stiffness, and tension

increases it. This type of geometric nonlinearity is

known as the P-Delta effect. This option is

particularly useful for considering the effect of

gravity loads upon the lateral stiffness of building

structures.

The P-Delta analysis in ETABS considers the P-

Delta effect of a single loaded state upon the

structure. This effect can be computed in one of

two ways:

Iterative - Based on Loads: As a specified

combination of static load patterns. For

example, this may be the sum of a dead load

pattern plus a fraction of a live load pattern.

This approach requires an iterative solution to

determine the P-Delta effect upon the

structure.

Non-iterative - Based on Mass: As a story-

by-story load upon the structure computed

automatically from the mass at each level. This

approach is approximate, but does not require

an iterative solution. When you select a P-

Delta option, it is performed before all linear

analyses in the same analysis run. The P-Delta

analysis essentially modifies the characteristics

of the structure, affecting the results of all

subsequent analyses performed. Because the

load causing the P-Delta effect is the same for

all linear analysis cases, their results may be

superposed in load combinations. Finally,

building codes typically recognize two types of

P-Delta effects: the first due to the overall

sway of the structure and the second due to the

deformation of the member between its ends.

ETABS can model both of those behaviors. It

is recommended that the former effect be

accounted for in the analysis by using the

initial P-Delta option, and that the latter effect

be accounted for in design by using the

applicable building code moment-

magnification factors. The design components

in ETABS operate in this manner.

1.6Nonlinear Static Analysis

Nonlinear static analysis can be used for a wide

variety of purposes, including : to analyze a

building for material and geometric nonlinearity; to

form the P-delta stiffness for subsequent linear

analyses; to perform static pushover analysis; to

investigate staged construction; and more.

Multiple nonlinear static analysis cases can be

defined. Each analysis case considers a single

pattern of loading, specified as a linear

combination of static load cases, acceleration loads,

and vibration mode shapes.




P-Delta: The P-Delta analysis option accounts

for the effect of a large compressive or tensile

load upon the transverse stiffness of members

in the structure. A nonlinear static load case

subjected to gravity loads with P-delta is often

an appropriate choice for determining the

initial conditions for other linear and nonlinear

load cases.

Large Displacements: Large displacements

analysis considers the equilibrium equations in

the deformed configuration of the structure.

This means that if the position or orientation of

an element changes, its effect upon the

structure is accounted for.

Static Pushover: Monitors nonlinear hinge

formation as building is pushed using

displacement control.

Staged Construction: Staged construction

allows you to define a sequence of stages

wherein you can add or remove portions of the

structure, selectively apply load to portions of

the building, and to consider time-dependent

material behavior.

1.7 Modal Analysis

Modal analysis calculates vibration modes for the

structure based on the stiffness’s of the elements

and the masses present. Those modes can be used

to investigate the behavior of a structure, and are

required as a basis for subsequent response

spectrum and time history analyses. Two types of

modal analysis are available: eigenvector analysis

and Ritz vector analysis. Only one type can be used

in a single load case. Modal analysis is always

linear. A modal load case may be based on the

stiffness of the full unstressed structure, or upon the

stiffness at the end of a nonlinear load case. By

using the stiffness at the end of a nonlinear case,

you can evaluate the modes under P-delta

conditions.

Eigenvector Analysis

Eigenvector/eigenvalue analysis determines the

undammed free-vibration mode shapes and

frequencies of the system. Those natural modes

provide an excellent insight into the behavior of the

structure. They can also be used as the basis for

response spectrum or time history analyses,

although Ritz vectors are strongly recommended

for those purposes. The eigenvector modes are

identified by numbers from 1 to n in the order the

modes are found by the program. Specify the

number of modes, N, to be found, and the program

will seek the N-lowest frequency (longest period)

modes. The eigenvalue is the square of the circular

frequency. The user specifies a cyclic frequency

(circular frequency/(2π)) range in which to seek the

modes. Modes are found in order of increasing

frequency, and although starting from the default

value of zero is appropriate for most dynamic

analyses, ETABS does allow the user to specify a

starting “shift frequency”; this can be helpful when

your building is subjected to higher frequency

input, such as vibrating machinery. ETABS also

offers an option for calculating residual-mass

(missing mass) modes for Eigen-analyses. In this

way, ETABS tries to approximate high-frequency

behavior when the mass participation ratio for a

given direction of acceleration load is less than

100%.

Ritz-Vector Analysis

ETABS offers the ability to use the sophisticated

Ritz-vector technique for modal analysis. Research

has indicated that the natural free-vibration mode

shapes are not the best basis for a mode-

superposition analysis of structures subjected to

dynamic loads. It has been demonstrated that

dynamic analyses based on load-dependent Ritz

vectors yield more accurate results than the use of

the same number of eigenvalue/eigenvector mode

shapes. Ritz vectors yield excellent results because

they are generated considering the spatial

distribution of the dynamic loading. The direct use

of the natural mode shapes neglects this important

information. Each Ritz-vector mode consists of a

mode shape and frequency. When a sufficient

number of Ritz-vector modes have been found,

some of them may closely approximate natural

mode shapes and frequencies. In general, however,

Ritz-vector modes do not represent the intrinsic

characteristics of the structure in the same way the

natural modes do because they are biased by the

starting load vectors. Similar to the natural modes,

specify the number of Ritz modes to be found. In

addition, specify the starting load vectors, which

may be acceleration loads, static load cases, or

nonlinear deformation loads.

Response Spectrum Analysis

For response spectrum analyses, earthquake ground

acceleration in each direction is given as a digitized

response spectrum curve of pseudo spectral

acceleration response versus period of the structure.

This approach seeks to determine the likely

maximum response rather than the full time

history.

ETABS performs response spectrum analysis using

mode superposition, and eigenvector or Ritz

vectors may be used. Ritz vectors are typically

recommended because they give more accurate

results for the same number of modes. Even though

input response spectrum curves may be specified in

three directions, only a single, positive result is

produced for each response quantity. The response

quantities may be displacements, forces, or

stresses. Each computed result represents a

statistical measure of the likely maximum

magnitude for that response quantity. Although all

results are reported as positive, actual response can

be expected to vary within a range from this

positive value to its corresponding negative value.




Linear Time History Analysis

Time history analysis is used to determine the

dynamic response of a structure to arbitrary

loading. ETABS can complete any number of

linear time history cases in a single execution of the

program. Each case can differ in the load applied

and in the type of analysis to be performed, and the

building may be subjected to a suite of time

histories using time history sets. Two types of

linear time history analyses are available:

Modal: The standard mode superposition

method of response analysis is used by the program

to solve the dynamic equilibrium equations of

motion for the complete structure. The modes used

can be the eigenvector or the load dependent Ritz

vector modes, and the damping in the structure is

modeled using modal damping, also known as

proportional or classical damping. The Ritz vector

algorithm is faster than the eigenvector algorithm,

and is therefore recommended for time history

analyses.

Direct Integration: This technique uses the

direct integration of the full equations of motion.

Although modal superposition is often more

accurate and efficient than direct integration, direct

integration provides better response when modes

are coupled or blast/impact type loads are involved.

Nonlinear Time History Analysis

As with the linear time history analysis, two types

of nonlinear analyses are available:

Modal: The method of nonlinear modal time-

history analysis used in ETABS is an

extension of the Fast Nonlinear Analysis

(FNA) method. This method is extremely

efficient and is intended for use with structural

systems that are primarily linear elastic, but

which have a limited number of predefined

nonlinear elements, such as buildings with

base isolators and/or dampers.

Direct Integration: Nonlinear direct

integration provides the same costs and

benefits as the linear procedure. Direct

integration results are extremely sensitive to

time-step size in a way that is not true for

modal superposition.. The FNA method is

highly accurate when used with appropriate

Ritz vector modes, and has advantages over

traditional time-stepping methods in terms of

speed, and control over damping and higher

mode effects.

Buckling: Linear buckling analysis seeks the

instability modes of a structure due to the P-

delta effect under a specified set of loads. Each

eigenvalue eigenvector pair is called a

buckling mode of the structure. The eigenvalue

is called the buckling factor. It is the scale

factor that loads must be multiplied by to cause

buckling in the given mode.

2.0 REVIEW LITERATURE

Prashanth.P, Anshuman.S, Pandey.R.K, Arpan

Herbert (2012), may conclude that E-TABS gave

lesser area of required steel as compared to

STAAD-PRO. It is found out from previous studies

on comparison of STAAD results with manual

calculations that STAAD-Pro gives conservative

design results which is again proved in this study

by comparing the results of STAAD-Pro, ETABS

and Manual calculations (refer below table). Form

the design results of column; since the required

steel for the column forces in this particular

problem is less than the minimum steel limit of

column (i.e., 0.8%), the amount of steel calculated

by both the software is equal. So comparison of

results for this case is not possible.

Bardakis & Dritsos (2007), evaluated the

American and European procedural assumptions

for the assessment of the seismic capacity of

existing buildings via pushover analyses. The

FEMA and the Euro code-based GRECO

procedures have been followed in order to assess a

four-storeyed bare framed building and a

comparison has been made with available

experimental results.

Ozyigit (2009), performed free and forced in-plane

and out-of-plane vibrations of frames are

investigated. The beam has a straight and a curved

part and is of circular cross section. A concentrated

mass is also located at different points of the frame

with different mass ratios. FEM is used to analyse

the problem.

Haroon Rasheed Tamboli & Umesh N. Karadi

[2012], performed seismic analysis using

Equivalent Lateral Force Method for different

reinforced concrete (RC) frame building models

that included bare frame, infilled frame and open

first story frame. In modelling of the masonry infill

panels the Equivalent diagonal Strut method was

used and the software ETABS was used for the

analysis of all the frame models. Infilled frames

should be preferred in seismic regions than the

open first story frame, because the story drift of

first story of open first story frame is very large

than the upper stories, which might probably cause

the collapse of structure. The infill wall increases

the strength and stiffness of the structure. The

seismic analysis of RC (Bare frame) structure lead

to under estimation of base shear. Therefore other

response quantities such as time period, natural

frequency, and story drift were not significant. The

underestimation of base shear might lead to the

collapse of structure during earthquake shaking.




Narender Bodige, Pradeep Kumar Ramancharla

[2012], modelled a 1 x 1 bay 2D four storied

building using AEM (applied element method).

AEM is a discrete method in which the elements

are connected by pair of normal and shear springs

which are distributed around the elements edges

and each pair of springs totally represents stresses

and deformation and plastic hinges location are

formed automatically. Gravity loads and laterals

loads as per IS 1893-2002 were applied on the

structure and designed using IS 456 and IS 13920.

Displacement control pushover analysis was

carried out in both cases and the pushover curves

were compared. As an observation it was found

that AEM gave good representation capacity curve.

From the case studies it was found that capacity of

the building significantly increased when ductile

detailing was adopted. Also, it was found that

effect on concrete grade and steel were not highly

significant

3.0 Design and Analysis

3.1 Story Data

Table 1.1 - Story Data

Name Height

mm

Elevation

mm

Master

Story

Similar

To

Splice

Story

Story30 3000 90000 Yes None No0

Story29 3000 87000 No Story30 No









0Story20 3000 60000 No Story30 No




















Base 0 0 No None No




3.2 Properties

This chapter provides property information for materials, frame sections, shell sections, and links.

3.2.1 Materials

Table 2.1 - Material Properties - Summary

Name Type E

MPa Ν

Unit

Weight

kN/m³

Design

Strengths

A615Gr6

0 Rebar

199947.9

8 0.3 76.9729

Fy=413.69 MPa,

Fu=620.53 MPa

M25 Concrete 25000 0.2 24.9926 Fc=25 MPa

Table 2.2 - Material Properties - Concrete

Name E

MPa ν

α

1/C

G

MPa

Unit

Weight

kN/m³

Unit

Mass

kg/m³

Fc

MPa

Lightwei

ght?

M25 25000 0.2 5.5E-06 10416.67 24.9926 2548.538 25 No

Table 2.3 - Material Properties - Rebar

Name E

MPa

α

1/C

Unit

Weight

kN/m³

Unit

Mass

kg/m³

Fy

MPa

Fu

MPa

A615Gr6

0

199947.9

8 1.17E-05 76.9729 7849.047 413.69 620.53

3.2.2 Frame Sections

Table 2.4 - Frame Sections - Summary

Name Material Shape

B300X42

0 M25

Concrete

Rectangular

C320X46

0 M25

Concrete

Rectangular

Table 2.5 - Frame Sections (Part 1 of 2)

Name Materia

l Shape

t3

mm

t2

mm

Area

cm²

AS2

cm²

AS3

cm²

J

cm⁴ I22

cm⁴ I33

cm⁴ S22

cm³

S33

cm³

B300X4

20 M25

Concrete

Rectangul

ar

420 300 1260 1050 1050 211589.

9 94500 185220 6300 8820

C320X4

60 M25

Concrete

Rectangul

ar

460 320 1472 1226.7 1226.7 286539.

1

125610.

7

259562.

7 7850.7 11285.3

Table 2.5 - Frame Sections (Part 2 of 2)

Name Z22

cm³

Z33

cm³

R22

mm

R33

mm

B300X42

0 9450 13230 86.6 121.2

C320X46

0 11776 16928 92.4 132.8

3.2.3 Shell Sections

Table 2.6 - Shell Sections - Summary




Name Design

Type

Element

Type Material

Total

Thicknes

s

mm

Slab125 Slab Membran

e M25 125

3.3 Reinforcement Sizes

Table 2.7 - Reinforcing Bar Sizes

Name Diameter

mm

Area

mm²

10 10 79

20 20 314

3.4 Analysis Results

This chapter provides analysis results.

3.4.1 Structure Results

Table 4.1 - Base Reactions

Load

Case/Co

mbo

FX

kN

FY

kN

FZ

kN

MX

kN-m

MY

kN-m

MZ

kN-m

X

M

Y

m

Z

m

Dead 0 0 41968.40

33

293778.8

234 -335747 0 0 0 0

Live 0 0 13440 94080 -107520 0 0 0 0

FF 0 0 6720 47040 -53760 0 0 0 0

EQX+ 1 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQX+ 2 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQX+ 3 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQX+ 4 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQX+ 5 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQX+ 6 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQX- 1 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQX- 2 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQX- 3 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQX- 4 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQX- 5 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0




Load

Case/Co

mbo

FX

kN

FY

kN

FZ

kN

MX

kN-m

MY

kN-m

MZ

kN-m

X

M

Y

m

Z

m

EQX- 6 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQY+ 1 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQY+ 2 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQY+ 3 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQY+ 4 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQY+ 5 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQY+ 6 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQY- 1 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQY- 2 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQY- 3 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQY- 4 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

EQY- 5 -529.1124 0 0 0

-

36193.31

43

3703.786

6 0 0 0

EQY- 6 0 -512.0046 0 35023.07

94 0

-

4096.037

1

0 0 0

DCon1 0 0 73032.60

5

511228.2

351 -584261 0 0 0 0

DCon2 0 0 93192.60

5

652348.2

351 -745541 0 0 0 0

DCon3

Max 0 0

74554.08

4

563906.2

833 -596433 4444.544 0 0 0

DCon3

Min -634.9349 -614.4056

74554.08

4

521878.5

88 -639865

-

4915.244

5

0 0 0

DCon4

Max 634.9349 614.4056

74554.08

4

521878.5

88 -553001

4915.244

5 0 0 0

DCon4

Min 0 0

74554.08

4

479850.8

928 -596433 -4444.544 0 0 0

DCon5

Max 0 0

74554.08

4

563906.2

833 -596433 4444.544 0 0 0

DCon5

Min -634.9349 -614.4056

74554.08

4

521878.5

88 -639865

-

4915.2440 0 0




Load

Case/Co

mbo

FX

kN

FY

kN

FZ

kN

MX

kN-m

MY

kN-m

MZ

kN-m

X

M

Y

m

Z

m

5

DCon6

Max 634.9349 614.4056

74554.08

4

521878.5

88 -553001

4915.244

5 0 0 0

DCon6

Min 0 0

74554.08

4

479850.8

928 -596433 -4444.544 0 0 0

DCon7

Max 0 0

74554.08

4

563906.2

833 -596433 4444.544 0 0 0

DCon7

Min -634.9349 -614.4056

74554.08

4

521878.5

88 -639865

-

4915.244

5

0 0 0

DCon8

Max 634.9349 614.4056

74554.08

4

521878.5

88 -553001

4915.244

5 0 0 0

DCon8

Min 0 0

74554.08

4

479850.8

928 -596433 -4444.544 0 0 0

DCon9

Max 0 0

74554.08

4

563906.2

833 -596433 4444.544 0 0 0

DCon9

Min -634.9349 -614.4056

74554.08

4

521878.5

88 -639865

-

4915.244

5

0 0 0

DCon10

Max 634.9349 614.4056

74554.08

4

521878.5

88 -553001

4915.244

5 0 0 0

DCon10

Min 0 0

74554.08

4

479850.8

928 -596433 -4444.544 0 0 0

DCon11

Max 0 0

73032.60

5

563762.8

541 -584261

5555.679

9 0 0 0

DCon11

Min -793.6686 -768.007

73032.60

5

511228.2

351 -638551

-

6144.055

6

0 0 0

DCon12

Max 793.6686 768.007

73032.60

5

511228.2

351 -529971

6144.055

6 0 0 0

DCon12

Min 0 0

73032.60

5

458693.6

16 -584261

-

5555.679

9

0 0 0

DCon13

Max 0 0

73032.60

5

563762.8

541 -584261

5555.679

9 0 0 0

DCon13

Min -793.6686 -768.007

73032.60

5

511228.2

351 -638551

-

6144.055

6

0 0 0

DCon14

Max 793.6686 768.007

73032.60

5

511228.2

351 -529971

6144.055

6 0 0 0

DCon14

Min 0 0

73032.60

5

458693.6

16 -584261

-

5555.679

9

0 0 0

DCon15

Max 0 0

73032.60

5

563762.8

541 -584261

5555.679

9 0 0 0

DCon15

Min -793.6686 -768.007

73032.60

5

511228.2

351 -638551

-

6144.055

6

0 0 0

DCon16

Max 793.6686 768.007

73032.60

5

511228.2

351 -529971

6144.055

6 0 0 0

DCon16

Min 0 0

73032.60

5

458693.6

16 -584261

-

5555.679

9

0 0 0

DCon17

Max 0 0

73032.60

5

563762.8

541 -584261

5555.679

9 0 0 0

DCon17 -793.6686 -768.007 73032.60 511228.2 -638551 - 0 0 0




Load

Case/Co

mbo

FX

kN

FY

kN

FZ

kN

MX

kN-m

MY

kN-m

MZ

kN-m

X

M

Y

m

Z

m

Min 5 351 6144.055

6

DCon18

Max 793.6686 768.007

73032.60

5

511228.2

351 -529971

6144.055

6 0 0 0

DCon18

Min 0 0

73032.60

5

458693.6

16 -584261

-

5555.679

9

0 0 0

DCon19

Max 0 0

43819.56

3

359271.5

601 -350557

5555.679

9 0 0 0

DCon19

Min -793.6686 -768.007

43819.56

3

306736.9

41 -404846

-

6144.055

6

0 0 0

DCon20

Max 793.6686 768.007

43819.56

3

306736.9

41 -296267

6144.055

6 0 0 0

DCon20

Min 0 0

43819.56

3

254202.3

219 -350557

-

5555.679

9

0 0 0

DCon21

Max 0 0

43819.56

3

359271.5

601 -350557

5555.679

9 0 0 0

DCon21

Min -793.6686 -768.007

43819.56

3

306736.9

41 -404846

-

6144.055

6

0 0 0

DCon22

Max 793.6686 768.007

43819.56

3

306736.9

41 -296267

6144.055

6 0 0 0

DCon22

Min 0 0

43819.56

3

254202.3

219 -350557

-

5555.679

9

0 0 0

DCon23

Max 0 0

43819.56

3

359271.5

601 -350557

5555.679

9 0 0 0

DCon23

Min -793.6686 -768.007

43819.56

3

306736.9

41 -404846

-

6144.055

6

0 0 0

DCon24

Max 793.6686 768.007

43819.56

3

306736.9

41 -296267

6144.055

6 0 0 0

DCon24

Min 0 0

43819.56

3

254202.3

219 -350557

-

5555.679

9

0 0 0

DCon25

Max 0 0

43819.56

3

359271.5

601 -350557

5555.679

9 0 0 0

DCon25

Min -793.6686 -768.007

43819.56

3

306736.9

41 -404846

-

6144.055

6

0 0 0

DCon26

Max 793.6686 768.007

43819.56

3

306736.9

41 -296267

6144.055

6 0 0 0

DCon26

Min 0 0

43819.56

3

254202.3

219 -350557

-

5555.679

9

0 0 0

Modal Results

Table 4.3 - Modal Periods and Frequencies

Case Mode Period

sec

Frequenc

y

cyc/sec

Circular

Frequenc

y

rad/sec

Eigenval

ue

rad²/sec²

Modal 1 4.384 0.228 1.4333 2.0543

Modal 2 3.871 0.258 1.6233 2.635

Modal 3 3.267 0.306 1.9232 3.6986




Case Mode Period

sec

Frequenc

y

cyc/sec

Circular

Frequenc

y

rad/sec

Eigenval

ue

rad²/sec²

Modal 4 1.438 0.695 4.3698 19.0954

Modal 5 1.264 0.791 4.9716 24.7165

Modal 6 1.084 0.922 5.7944 33.575

Modal 7 0.783 1.276 8.0198 64.3178

Modal 8 0.691 1.448 9.0984 82.7813

Modal 9 0.643 1.554 9.7646 95.3483

Modal 10 0.547 1.829 11.4893 132.0051

Modal 11 0.481 2.077 13.0498 170.2983

Modal 12 0.454 2.201 13.8276 191.2026

Table 4.4 - Modal Participating Mass Ratios (Part 1 of 2)

Case Mode Period

sec UX UY UZ Sum UX Sum UY Sum UZ

Modal 1 4.384 0 0.8114 0 0 0.8114 0

Modal 2 3.871 0.8054 0 0 0.8054 0.8114 0

Modal 3 3.267 0 0 0 0.8054 0.8114 0

Modal 4 1.438 0 0.1316 0 0.8054 0.943 0

Modal 5 1.264 0.1305 0 0 0.936 0.943 0

Modal 6 1.084 0 0 0 0.936 0.943 0

Modal 7 0.783 0 0.0308 0 0.936 0.9738 0

Modal 8 0.691 0.0321 0 0 0.9681 0.9738 0

Modal 9 0.643 0 0 0 0.9681 0.9738 0

Modal 10 0.547 0 0.012 0 0.9681 0.9858 0

Modal 11 0.481 0.0134 0 0 0.9814 0.9858 0

Modal 12 0.454 0 0 0 0.9814 0.9858 0

Table 4.4 - Modal Participating Mass Ratios (Part 2 of 2)

Case Mode RX RY RZ Sum RX Sum RY Sum RZ

Modal 1 0.1918 0 0 0.1918 0 0

Modal 2 0 0.1976 0 0.1918 0.1976 0

Modal 3 0 0 0.8551 0.1918 0.1976 0.8551

Modal 4 0.6188 0 0 0.8106 0.1976 0.8551

Modal 5 0 0.5977 0 0.8106 0.7953 0.8551

Modal 6 0 0 0.0897 0.8106 0.7953 0.9449

Modal 7 0.0823 0 0 0.8928 0.7953 0.9449

Modal 8 0 0.0819 0 0.8928 0.8772 0.9449

Modal 9 0 0 0.0278 0.8928 0.8772 0.9727

Modal 10 0.0553 0 0 0.9481 0.8772 0.9727

Modal 11 0 0.0583 0 0.9481 0.9354 0.9727

Modal 12 0 0 0.0117 0.9481 0.9354 0.9844

Table 4.5 - Modal Load Participation Ratios

Case Item

Type Item

Static

%

Dynamic

%

Modal Accelerati

on UX 99.99 98.14

Modal Accelerati

on UY 99.99 98.58

Modal Accelerati

on UZ 0 0

Table 4.6 - Modal Direction Factors

Case Mode Period

sec UX UY UZ RZ

Modal 1 4.384 0 1 0 0




Case Mode Period

sec UX UY UZ RZ

Modal 2 3.871 1 0 0 0

Modal 3 3.267 0 0 0 1

Modal 4 1.438 0 1 0 0

Modal 5 1.264 1 0 0 0

Modal 6 1.084 0 0 0 1

Modal 7 0.783 0 1 0 0

Modal 8 0.691 1 0 0 0

Modal 9 0.643 0 0 0 1

Modal 10 0.547 0 1 0 0

Modal 11 0.481 1 0 0 0

Modal 12 0.454 0 0 0 1

4.1 Concrete Frame Design

Table 1.1 - Concrete Frame Preferences - IS 456-2000

Item Value

Multi-Response

Design

Step-by-Step

- All

# Interaction

Curves 24

# Interaction

Points 11

Minimum

Eccentricity Yes

Additional

Moment Yes

Gamma (Steel) 1.15

Gamma

(Concrete) 1.5

Pattern Live

Load Factor 0.75

D/C Ratio Limit 1

Table 1.2 - Concrete Column Overwrites - IS 456-2000 (Part 1 of 2)

Story Label Unique

Name

Design

Type

Design

Section LLRF LMajor LMinor

KMajor(S

way)

KMinor(S

way)

KMajor(Br

aced)

Story30 C1 1287 Column Program

Determined 1 0.86 0.86 2.041025 1.540526 0.815732


Determined 1 0.86 0.86 2.041025 1.302652 0.815732


Determined 1 0.86 0.86 2.041025 1.302652 0.815732


Determined 1 0.86 0.86 2.041025 1.302652 0.815732


Determined 1 0.86 0.86 2.041025 1.540526 0.815732


Determined 1 0.86 0.86 1.616952 1.540526 0.729591


Determined 0.949879 0.86 0.86 1.616952 1.302652 0.729591


Determined 0.939035 0.86 0.86 1.616952 1.302652 0.729591


Determined 0.949879 0.86 0.86 1.616952 1.302652 0.729591


Determined 1 0.86 0.86 1.616952 1.540526 0.729591


Determined 1 0.86 0.86 1.616952 1.540526 0.729591




Story Label Unique

Name

Design

Type

Design


KMajor(S

way)

KMinor(S

way)

KMajor(Br

aced)


Determined 0.934939 0.86 0.86 1.616952 1.302652 0.729591


Determined 0.92346 0.86 0.86 1.616952 1.302652 0.729591


Determined 0.934939 0.86 0.86 1.616952 1.302652 0.729591


Determined 1 0.86 0.86 1.616952 1.540526 0.729591


Determined 1 0.86 0.86 1.616952 1.540526 0.729591


Determined 0.949879 0.86 0.86 1.616952 1.302652 0.729591


Determined 0.939035 0.86 0.86 1.616952 1.302652 0.729591


Determined 0.949879 0.86 0.86 1.616952 1.302652 0.729591


Determined 1 0.86 0.86 1.616952 1.540526 0.729591


Determined 1 0.86 0.86 2.041025 1.540526 0.815732


Determined 1 0.86 0.86 2.041025 1.302652 0.815732


Determined 1 0.86 0.86 2.041025 1.302652 0.815732


Determined 1 0.86 0.86 2.041025 1.302652 0.815732


Determined 1 0.86 0.86 2.041025 1.540526 0.815732


Determined 0.838655 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.804578 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.794715 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.804578 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.838655 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.80667 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.765708 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.755618 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.765708 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.80667 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.795631 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.754578 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.744229 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.754578 0.86 0.86 1.800611 1.396223 0.775735

Story29 C15 1708 Column Program 0.795631 0.86 0.86 1.800611 1.702609 0.775735




Story Label Unique

Name

Design

Type

Design


KMajor(S

way)

KMinor(S

way)

KMajor(Br

aced)

Determined


Determined 0.80667 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.765708 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.755618 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.765708 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.80667 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.838655 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.804578 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.794715 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.804578 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.838655 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.724005 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.701629 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.693762 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.701629 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.724005 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.701438 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.675113 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.666911 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.675113 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.701438 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.692784 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.666245 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.65788 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.666245 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.692784 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.701438 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.675113 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.666911 0.86 0.86 1.800611 1.396223 0.775735




Story Label Unique

Name

Design

Type

Design


KMajor(S

way)

KMinor(S

way)

KMajor(Br

aced)


Determined 0.675113 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.701438 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.724005 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.701629 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.693762 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.701629 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.724005 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.657714 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.640607 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.633797 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.640607 0.86 0.86 2.34188 1.396223 0.857809


Determined 0.657714 0.86 0.86 2.34188 1.702609 0.857809


Determined 0.639672 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.620008 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.612848 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.620008 0.86 0.86 1.800611 1.396223 0.775735


Determined 0.639672 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.632273 0.86 0.86 1.800611 1.702609 0.775735


Determined 0.612365 0.86 0.86 1.800611 1.396223 0.775735




4.1.1 ETABS 2015 Concrete Frame Design

IS 456:2000 Column Section Design (Flexural Details)

Column Element Details Type: Sway Special (Flexural Details)

Level Element Section ID Combo ID Station Loc Length (mm) LLRF

Story30 B4 B300X420 DCon26 3340 3500 1

Section Properties

b (mm) h (mm) dc (mm) Cover (Torsion) (mm)

300 420 60 30

Material Properties

Ec (MPa) fck (MPa) Lt.Wt Factor (Unitless) fy (MPa) fys (MPa)

25000 25 1 413.69 413.69

Design Code Parameters

ɣC ɣS

1.5 1.15

Axial Force and Biaxial Moment Design For Pu , Mu2 , Mu3

Design Pu

Kn

Design Mu2

kN-m

Design Mu3

kN-m

Minimum M2

kN-m

Minimum M3

kN-m

Rebar Area

mm²

Rebar %

%

0 0 0 0 0 0 0

Factored & Minimum Biaxial Moments

NonSway Mns

kN-m

Sway Ms

kN-m

Factored Mu

kN-m

Major Bending(Mu3 ) 0 0 0

Minor Bending(Mu2 ) 0 0 0

Slenderness Effects (IS 39.7.1) and Minimum Biaxial Moments (IS 39.2, 25.4) (Part 1 of 2)

End Moment

Mu1 (kN-m)

End Moment

Mu2 (kN-m)

Initial

Moment (kN-m)

k*Ma

Moment (kN-m)

Major Bending (M3 ) 0 0 0 0

Minor Bending (M2 ) 0 0 0 0

Slenderness Effects (IS 39.7.1) and Minimum Biaxial Moments (IS 39.2, 25.4) (Part 2 of 2)




Minimum

Moment (kN-m)

Minimum

Eccentricity (mm)

0 0

0 0

Effective Length Factors (IS 25.2, Annex E)

K

Sway

K

Non-Sway

Framing

Type

P-Delta

Done?

Q

Factor

K

Used

Major Bend(M3 ) 0 0 Sway Special No 0 0

Minor Bend(M2 ) 0 0 Sway Special No 0 0

Additional Moment Reduction Factor k (IS 39.7.1.1)

Ag

cm²

Asc

cm²

Puz

kN

Pb

Kn

Pu

kN

k

Unitless

0 0 0 0 0 0

Additional Moment (IS 39.7.1) (Part 1 of 2)

Consider

Ma

Length

Factor

Section

Depth (mm)

KL/Depth

Ratio

KL/Depth

Limit

KL/Depth

Exceeded

Major Bending (M3 ) Yes 0 0 0 0 No

Minor Bending (M2 ) Yes 0 0 0 0 No

Design Images:

CONCLUSIONS

From our results obtained from the analyses

outputs, the elements are in accordance to our

objectives of the study which are:

1. The dead, live and floor finish loads obtained

by the ETABS are similar to the manually

calculated values

2. Analysis of the structural integrity of these

buildings in withstanding the design

earthquake loadings was conducted and was

judged to be safe 3. The way forward will be to conduct

studies on different shapes and

geometrical configurations and to see the

variations as the study we conducted only

included regular rectangular shape and

symmetrical configuration




REFERENCES

[1] ACI Committee 318. (2002) Building code requirements

for reinforced concrete (ACI 318-02). American Concrete

Institute, Detroit, MI [2] AISC.(2002) Seismic provisions for structural steel

buildings. (Chicago (IL): American Institute of Steel Construction. Aristizabal-Ochoa, J.D. (1986). Disposable

knee bracing: improvement in seismic design of steel

frames. Journal of Structural Engineering, 112 (7): 1544-1552.

[3] Abou-Elfath, H. & Ghobarah, A. (2000). Behaviour of

reinforced concrete frames rehabilitated with concentric steel bracing. Canadian Journal of Civil Engineering. 27

433-444.

[4 Balendra, T., Yu, C.Y., & Xiao, Y. (2001). An economical structural system for wind and earthquake loads.

Engineering Structures, 23: 491-501.

[5] Badoux, M. & Jirsa, O. (1990). Steel bracing of RC frames for seismic retrofitting. Journal of Structural Enineering.

ASCE, No. 1, 116, 55-74.

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