Analysis and Design of Irregular Building (G+13) using Non ...ijitech.org/uploads/452136IJIT16176-477.pdf · The seismic analysis of the proposed building was done in the software

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ISSN 2321-8665

Vol.05,Issue.12,

December-2017,

Pages:2518-2525

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Analysis and Design of Irregular Building (G+13) using Non Linear Static

Method in Etabs S. KARUNAKAR REDDY

1, SYED RIZWAN

2, A. B. S. DADAPEER

3

1PG Scholar, Chiranjeevi Reddy Institute of Engineering & Technology, Anantapur, AP, India.

2Assistant Professor, Chiranjeevi Reddy Institute of Engineering & Technology, Anantapur, AP, India.

3Assistant Professor & HOD, Chiranjeevi Reddy Institute of Engineering & Technology, Anantapur, AP, India.

Abstract: The One of the major problems that the country

facing is the rapidly growing population, which necessities

more facilities in the restricted availability of land. This can be

solved to a certain extent with the construction of multistoried

building, which can serve many people in available limited

area. Hence it is the necessary requirement of multistoried

building with all facilities. Hence an attempt is made in the

project by analysis and design of irregular building (g+13)

using non linear static method in etabs. Earthquake

Engineering was developed a lot from the early days and

seismically analyzing the structures requires specialized

explicit finite element analysis software, which divides the

element into very small slices and models the actual physics.

The seismic analysis of the proposed building was done in the

software ETABS 2013, which is one of the most Advanced

software in the structural design field. The loads applied on the

structure was based on IS:875(part I)-1987[dead load], IS:875

(part II)-1987[live load], IS:875(part III)-1987[wind load],

IS:1893-2000 [Earthquake load]. Scale factor is calculated

from the design base shear (Vb) to the base shear calculated

using fundamental time period (Ta). Once the analysis was

completed all the structural components were designed

according to Indian standard code IS:456-2000. Footing,

columns, beams, slab, staircase and shear wall were designed.

Ductile detailing of the structural elements were done as per

code IS:13920-1993.

Keywords: Self Organizing Maps(SOM), MLP, ANN, Action

Recognition and Detection.

I. INTRODUCTION

The advancement and latest development of major

construction is largely associated with improving the efficiency

of the building under seismic effect, reducing cost, economic

use of new materials etc., concrete is one such material, which

is consumed in construction industry next to water

consumption in the world. This marvelous material is strong in

compression but very weak in tension. Use of dispersed

reinforcement in the cement based matrix/concrete attains

promising new material and eliminates certain drawbacks and

entrances certain property.

A. Historical Back Ground

Exact0seismic0analysis of the0structure is0highly complex

and to tackle this complexity, number of0researches has been

done with an0aim to counter the0complex dynamic0effect

of0seismic0induced forces in0structures.This0re-examination

and continuous effort has0resulted in several0revisions of

Indian Standard: 1893 (1962, 1966, 1970, 1975, 1984 and

2002) code of practice on Criteria for earthquake

resistant0design of0structuresby the0Bureau0of0Indian

Standards (BIS),0New Delhi. Many of the analysis

techniques are being used in0design and incorporated in

codes of0practices of many0countries. However, since in

the0present study our main focus is on the IS a0codal

provision, the0method of0analysis0described in IS 1893 (Part

1): 2002 are0presented in this0chapter.

B. Seismic0design0philosophy

The0design0philosophy0adopted in the0seismic0code is to

ensure that structures0possess at0least a0minimum strength

to

Resist0minor0earthquakes0which

may0occur0frequently0without0damage.

Resist0moderate0earthquake0without0significant0structu

ral0damageand0minor0non-structural0damage.

Resist0major0earthquake0without0collapse.

Design0Basis Earthquake(DBE) is defined as the maximum

earthquake that reasonably can be0expected to0experience at

the0site once during0lifetime of the structure.The0earthquake

corresponding to the0ultimate0safety0requirements is often

calledas0maximum0considered0earthquake(MCE).Generally,

DBE is half of 0MCE.

C. Design0Lateral0Force

The procedure recommended for the determination of lateral

force in IS: 1893-2002(Part 1) performing are based on the

approximation that effects of yielding can be accounted for

by linear analysis of the building using design spectrum. This

analysis is carried out by either equivalent lateral force

procedure or dynamic analysis procedure given in the clause

7.8 of IS: 1893-2002 (Part 1). The main difference between

the two procedures lies in the magnitude and distribution of

lateral forces over the height of the building. In the dynamic

analysis procedure, the lateral forces are based on properties

of the natural vibration modes of the building which are

determined by distribution of mass and stiffness over the

height. In the equivalent lateral force procedure the

S. KARUNAKAR REDDY, SYED RIZWAN, A. B. S. DADAPEER

International Journal of Innovative Technologies

Volume.05, Issue No.12, December-2017, Pages: 2518-2525

magnitude of forces is based on an estimation of the

fundamental period and on the distribution of forces as given

by a simple empirical formula that is appropriate only for

regular buildings. The following sections will discuss in detail

the above mentioned procedures of seismic analysis.

D. Equivalent Lateral Force Method

The total design lateral force or design base shear along any

principal direction is given in terms of design horizontal

seismic coefficient and seismic weight of the structure. Design

horizontal seismic coefficient depends on the zone factor of the

site, importance of the structure, response reduction factor of

the lateral load resisting elements and the fundamental period

of the structure.The procedure generally used for the equivalent

static analysis is explained below:

i. Determination of fundamental natural period (Ta)of the

buildings

Ta =0.075h0.75Moment resisting RC frame building without

brick infill wall

Ta =0.085h0.75Moment resisting steel frame building without

brick infill walls

Where,

h -is the height of building in m

d - is the base of building at plinth level in m, along the

considered direction of lateral force.

ii. Determination of base shear (VB) of the building

VB =Ah×W

Where,

(1)

Is the design horizontal seismic coefficient, which depends

on the seismiczone factor (Z), importance factor (I), response

reduction factor (R) and the average response acceleration

coefficients (Sa/g). Sa/g in turn depends on the nature of

foundation soil (rock, medium or soft soil sites), natural period

and the damping of the structure.

iii. Distribution of design base shear. The design base shear VB

thus obtained shall be distributed along the height of the

building as per the following expression:

(2)

Where, Qi is the design lateral force, Wi is the seismic weight,

hi is the height of the 1thfloor measured from base and n is

thenumber of stories in the building.

Response Spectrum Method: The response spectrum

technique is really a simplified special case of modal analysis.

The modes of vibration are determined in period and shape in

the usual way and the maximum response magnitudes

corresponding to each mode are found by reference to a

response spectrum. The response spectrum method has the

great virtues of speed and cheapness. There are two major

disadvantages of using this approach. First, the method

produces a large amount of output information that can

require an enormous amount of computational effort to

conduct all possible design checks as a function of time.

Second, the analysis must be repeated for several different

earthquake motions in order to assure that all the significant

modes are excited, since a response spectrum for one

earthquake, in a specified direction, is not a smooth function.

According to the code, dynamic analysis may be performed

using either response spectrum method or the time history

method. In either method, the design base shear (VB) is

compared with a base shear VBcalculated using the

fundamental period Ta. It suggests that when VB is less than

VB, all the response quantities (for example member forces,

displacements, Storey force, Storey shears and base

reactions) must be suitably scaled by multiplying with

VB/VB. As per IS: 1893-2002 (PART 1) provisions, dynamic

analysis shall be performed to obtain the design seismic

force, and its distribution to different levels along the height

of the building and to the various lateral load resisting

elements, for the following buildings:

Regular buildings: Those greater than 40 m in

height in Zones IV and V, and those greater than 90

m in height in Zones II and III.

Irregular buildings: All framed buildings higher

than 12m in Zones IV and V, and those greater than

40m in height in Zones II and III.

Introduction: ETABS is sophisticated software for analysis

and design program developed specifically for buildings

systems. ETABS version-2013.1.5 features an in intuitive and

powerful graphical interface coupled with unmatched

modeling, analytical, and design procedures, all integrated

using 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, making it the tool of choice for

structural engineers in the building industry. The ETABS

building is idealized as an assemblage of area, line and point

objects. Those objects are used to represent wall, floor,

column, beam, brace and link / spring physical members. The

basic frame geometry is defined with reference to a simple

three-dimensional grid system. With relatively simple

modeling techniques, very complex framing situations may

be considered. The building may be unsymmetrical and non-

regulator in plan, Torsional behavior of the floors and

understory compatibility of the floors are accurately reflected

in the results. The solution enforces complete three-

dimensional displacement compatibility, making it possible

to capture tubular effects associated with the behavior of tall

structures having relatively closely spaced columns.

Semi-rigid floor diaphragms may be modeled to capture

the effects of in plane floor deformations. Floor objective

may span between adjacent levels to create sloped floors

(ramps), which can be useful for modeling parking garage

structures. Static analysis for user specified vertical and

lateral floor on story loads are possible. If floor elements with

plate bending capability are modeled, vertical uniform loads

Analysis and Design of Irregular Building (G+13) Using Non Linear Static Method in Etabs



on the floor are transferred to the beams and columns through

bending of the floor elements. The program can automatically

generate lateral wind and seismic load patterns to meet the

requirements of various building codes. Three dimensional

mode shapes and frequencies, model participation factors,

direction factors and participating mass percentage are

evaluated using Eigen vector or Ritz-vector analysis-Delta

analysis effects may be included with static or dynamic

analysis. Response spectrum analysis, linear time history

analysis, nonlinear analysis and static nonlinear analysis are

possible. The static nonlinear capabilities also allow you to

perform incremental construction analysis, so that forces that

arise as a result of construction sequence are included. Results

from the various static load cases may be combined with each

other or with the results from the dynamic response dynamic

response spectrum or time history method. Output may be

viewed graphically, displayed in tabular output, the types of

output include reactions, member forces, mode shapes,

participation factors, static and dynamic story displacements

and story shears inter story drifts and joint displacements, time

history traces and more.

II. LOAD CALCULATIONS

A. General Data

Structure = G + 13

Floor height = 3.0 m

Grade of concrete = M 35

Unit weight of concrete = 25kN/m3

Unit weight of cement mortar = 24kN/m3

Unit weight of water = 10kN/m3

Unit weight of Brick = 20kN/m3

B. Design Wind Pressure

The design wind pressure at any height above mean

ground level shall be obtained by the following relationship

between wind pressure and wind velocity

(3)

Wind Forces: The value of force coefficient apply to the

building or structure as a whole and multiplied by effective

frontal area of the building by design wind pressure, Pz gives

the total wind load on that particular building or structure. The

force coefficients are given in two mutually perpendicular

directions relative to reference axis of the structural

member. They are designed as Cpn and Cpt, give the normal

and transverse, respectively to the reference plane.

(4)

(5)

Basic wind speed at Agartala (As per IS 875-1987)

=33km/s (Vb) Terrain category (clause 5.3.2.1)

= 2

Building class (B=36m, W=53.0) (clause 5.3.2.2)

= C Risk coefficient (K1) (Assume 100 years Life period)

= 1.08

Topography factor (K3)(clause 5.3.2.3 = 1

a=53.0m a=53.0m b=36m h=28.0m

In X-direction (h/b) = 0.78

In Y-direction (h/a)= 0.53

Width of building in X-direction= 53.0m

Width of building in Y-direction= 36m

1. Value of Topography Factor (k2) - Table 1

TABLE I:

Force coefficient in X-direction = 1.075(from code IS 875-

1987(part3))

Force coefficient in Y-direction = 1.20(from code IS 875-

1987(part 3)) Design speed Vz = Vb× K1 × K2 × K3

Seismic load calculation (Based on code IS 1893-2002):

During an earthquake, ground motions develop in a random

manner both horizontally and vertically in all directions

radiating from the epicenter. The ground motions develop

vibrations in the structure inducing inertial forces on them.

Hence structures located in seismic zones should be suitably

designed and detailed to ensure strength, serviceability and

stability with acceptable levels of safety under seismic forces.

The satisfactory performance of a large number of reinforced

concrete structures subject to severe earthquake in various

parts of the world has demonstrated that it is possible to

design structures to successfully withstand the destructive

effects of major earthquakes. The Indian standard codes IS:

1893-1984 and IS: 13920-1993 have specified the minimum

design requirements of earthquake resistant design

probability of occurrence of earthquakes, the characteristics

of the structure and the foundation and the acceptable

magnitude of damage. Determination of design earthquake

forces is computed by the following methods,

Equivalent static lateral loading.

Dynamic Analysis.

In the first method, different partial safety factors are

applied to dead, live, wind earthquake forces to arrive at the

design ultimate load. In the IS: 456-2000 code, while

considering earthquake effects, wind loads assuming that

both severe wind and earthquake do not act simultaneously.

The American and Australian code recommendations are

similar but with different partial safety factors. The dynamic

analysis involves the rigorous analysis of the structural

system by studying the dynamic response of the structure by

considering the total response in terms of component modal

responses.

C. Zone Factor (Z)

The values of peak ground acceleration given in

units ‘g’ for the maximum considered earthquake.




The value of (Z/2) corresponds to design basis earthquake

damage control in limit state.

Based on history of seismic activities seism tectonic

understanding the entire country has been divided in to

four zones. The zone factor from table 2(IS 1893:2002)

TABLE II: Zone Factor Values

D. Response Reduction Factor (R)

R is the response reduction factor and controls the

permitted damage in design basis earthquake.

The minimum value of R is 3 and maximum is 5 however

to use higher values of R special ductile detailing

requirements are must and the designer is accepting more

damages but in the controlled manner. The Response

reduction factor from table 7(IS1893:2002).

E. Importance Factor (I)

I is the importance factor and permitted damage could be

reduced by setting the value of is more than ‘1’.

F. Seismic Weight (W)

Seismic weight of the building is measured in Newton.

Seismic weight includes the dead loads (that of floor,

slabs, finishes, columns, beams, water tanks, permanent

machines etc.

Seismic weight includes only a part of Imposed loads, for

example 25% to 50% of imposed loads for buildings from

table 8 (IS 1893:2002).

G. Soil Classification

Sa/g is the lateral acceleration to be established in m/s2.

For 5 present of damping three different types of curves

are recommended in IS 1893:2002 for different

stiffness of supporting media-Rock, Medium soil and Soft

soil.

The classification of soil is based on the average shear

velocity for 30m of rock or soil layers or based on average

Standard Penetration Test (SPT) values for top 30m.

Zone factor of the building (Z) = 0.1 (Zone II)

Indian IS875:1987 Auto Wind Load Calculation: This

calculation presents the automatically generated lateral wind

loads for load pattern WX according to Indian IS875:1987, as

calculated by ETABS.

Exposure Parameters:

Exposure From = Diaphragms

Structure Class = Class B

Terrain Category = Category 2

Wind Direction = 0 degrees

Basic Wind Speed, Vb [IS Fig. 1]

Windward Coefficient, Cp,wind Cp,wind=0.8

Leeward Coefficient, Cp,lee Cp,lee=0.5

Top Story = 13RF

Bottom Story = GRF

Include Parapet = No

Factors and Coefficients:

Risk Coefficient, k1 [IS 5.3.1] k1=1

Topography Factor, k3 [IS 5.3.3] k3=1

Lateral Loading:

Design Wind Speed, Vz [IS 5.3]

Vz=37.0363125

Design Wind Pressure, pz [IS 5.4]

Applied Story Forces:

TABLE III:

Dead Load (As per IS 875 part I):

Typical Floor Slab:

Self-weight of slab (150mm thick) = 3.75 kN/m2

Floor Finish = 1.5 kN/m2

Total Load = 5.25 kN/m2




Terrace Floor Slab:

Self-weight of slab (150mm thick) = 3.75 kN/m2

Terrace (Roof finish + Water proofing) = 3.20 kN/m2

Total Load = 6.95 kN/ m2

Live Load (As per IS 875 part II):

Living room, Toilet & Bath room = 3.00 kN/m2

General Rooms = 2.00 kN/m2

Corridors & stair case = 3.00 kN/m2

Terrace Floor = 1.5 kN/m2

Balcony/Utility =3.00 kN/m2

Wall Load: Member load due to 230mm thick exterior wall

Wall thickness = 230 mm

Floor Height = 3200 mm

Beam Depth = 450 mm (0.23 × (3-0.45) × 20) = 11.7kN/m

III. MODELLING AND ANALYSIS

A. Define Geometry

The Building Plan Grid System and Storey Data form is

used to specify horizontal and vertical grid line spacing, storey

data, storey elevation and units. They automatically add the

structural objects with appropriate properties to the model as

shown in Figs.1 and 2.

Fig.1 &2 - Building Plan Grid System and Storey Data

Definition.

B. Define Material Property

The material properties of each object in the model is

specified in the appropriate form. The material used is

concrete, the grade of concrete, the properties of concrete

such as Mass per unit volume, Modulus of Elasticity of

concrete, Poisson ratio are specified and for steel yield

strength is specified as shown in Figs.3 to 5.




Fig.3,4&5 - Material property data.

C. Define Frame Section

Assign the frame section such as Column and Beam. Select

the section property as Rectangle and define the depth, width

and reinforcement details, cover provisions. Similarly for

various sections like circular pipe, steel joist sections also

assigned with suitable data as shown in Figs.6 to 9.

Fig.6,7,8&9- Section properties and Reinforcement

details.

IV. MODEL OUTPUT

Model output of this paper is as shown in bellow Figs.20 to

25.

A. Output: 3d-Model Of A Rc Frame




Fig.20&21-3D model of RC frame.

B. Bending Moment Diagram From Analysis

Fig.22 & 23.Bending Moment from analysis.

C. Shear Force From Analysis

Fig. 24&25- Shear Force from analysis.

V. CONCLUSION

The Nonlinear Residential building was designed with the

earthquake resistant design consideration in Nonlinear static

method, analysis and design were done by using ETABS

software. The detailing of the structural elements were done

as per IS 13920-1993(Ductile detailing for Earthquake

resistant structures). To conclude a complete design involving

several parameters so as to result the earthquake has been

done.

VI. REFERENCES

[1] “Comparative Study of the Static and Dynamic Analysis

of Multi-Storey Irregular Building” Bahador Bagheri, Ehsan

Salimi Firoozabad, and Mohammadreza Yahyaei

[2]. Static and Dynamic Behaviour of Reinforced Concrete

Framed Building: A Comparative Study

[3]. Prakash Sangamnerkar*, Dr. S. K. Dubey,

[4].Design Cell,M.P.Housing and Infrastructure Development

Board, Bhopal (M.P.) 462013




[5]. Professor, Deptt. Of Civil Engineering, Maulana Azad

National Institute of Technology, Bhopal (M.P.) 462051

[6]. Response Analysis of Multi-Storey RC Buildings under

Equivalent Static and Dynamic Loads According to Egyptian

Code Sayed Mahmoud1, Waleed Abdallah2 1Department of

Construction Engineering, College of Engineering, Dammam

University Dammam, Saudi Arabia 2Faculty of Engineering at

Mataria, Helwan University Cairo, Egypt

[7].Static and Dynamic Behavior of Reinforced Concrete

Framed Building: A Comparative Study

[8]. Prakash Sangamnerkar*, Dr. S. K. Dubey

[9]. Design Cell,M. P. Housing and Infrastructure Development

Board, Bhopal (M.P.) 462013

[10].Professor, Deptt. Of Civil Engineering, Maulana Azad

National Institute of Technology, Bhopal (M.P.)

[11].Bureau of Indian Standards:IS-875,part (1) 1987,Dead

loads on Buildings and Structures, New Delhi, India

[12].Bureau of Indian Standards:IS-875,part (2) 1987, Live

loads on Buildings and Structures, New Delhi, India

[13].Bureau of Indian Standards:IS-1893, part (1)

2002,Criteriaof Eqrth quakeResitant Design of Structures: part

1 General provisions on Buildings, New Delhi, India.

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Analysis and Design of Irregular Building (G+13) using Non ...ijitech.org/uploads/452136IJIT16176-477.pdf · The seismic analysis of the proposed building was done in the software