g+10 HIGH RISE BUILDING

8/18/2019 g+10 HIGH RISE BUILDING

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ABSTRACT

Design and Analysis of high rise Building (G+10) using of staad pro in limit state method

analysis of staad pro methods used in STAAD-Pro analysis are imit State Design !onforming to

"ndian Standard #ode of Pra!ti!e$ STAAD$Pro features a state-of-the-art user interfa!e%&isuali'ation tools% poerful analysis and design engines ith ad&an!ed finite element and

dynami! analysis !apailities$ *rom model generation% analysis and design to &isuali'ation and

result &erifi!ation% STAAD$Pro is the professionals !hoi!e$ "nitially e started ith the analysis

of simple , dimensional frames and manually !he!ed the a!!ura!y of the softare ith our

results$ The results pro&ed to e &ery a!!urate$ .e analy'ed and designed a G + 10 storey

uilding /,-D *rame initially for all possile load !ominations /dead% li&e% ind and seismi!

loads$STAAD$Pro has a &ery intera!ti&e user interfa!e hi!h allos the users to dra the frame

and input the load &alues and dimensions$ Then a!!ording to the spe!ified !riteria assigned it

analyses the stru!ture and designs the memers ith reinfor!ement details for ## frames$ .e

!ontinued ith our or ith some more multi-storied ,-D and 2-D frames under &arious load

!ominations$

3ur final or as the proper analysis and design of a G + 10 2-D ## frame under

&arious load !ominations$

.e !onsidered a 2-D ## frame ith the dimensions of 4 ays 56m in 7-a7is and 2

ays 56m in '-a7is$ The y-a7is !onsisted of G + 10 floors$ The total numers of eams in ea!h

floor ere ,8 and the numers of !olumns ere 19$ The ground floor height as 4m and rest of

the 10 floors had a height of 2$0m$The stru!ture as su:e!ted to self eight% dead load% li&e

load% ind load and seismi! loads under the load !ase details of STAAD$Pro$ The ind load

&alues ere generated y STAAD$Pro !onsidering the gi&en ind intensities at different heights

and stri!tly aiding y the spe!ifi!ations of "S 8;6$ Seismi! load !al!ulations ere donefolloing "S 18


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The !odes of pra!ti!e to e folloed ere also spe!ified for design purpose ith other

important details$ The minimum re=uirements pertaining to the stru!tural safety of uildings are

eing !o&ered y ay of laying don minimum design loads hi!h ha&e to e assumed

for dead loads% imposed loads% and other e7ternal loads% the stru!ture ould e re=uired to ear$

Stri!t !onformity to loading standards re!ommended in this !ode% it is hoped% ill ensure the

stru!tural safety of the uildings hi!h are eing designed$ Stru!ture and stru!tural elements

ere normally designed y imit State >ethod$

#ompli!ated and high-rise stru!tures need &ery time taing and !umersome !al!ulations

using !on&entional manual methods$ STAAD$Pro pro&ides us a fast% effi!ient% easy to use and

a!!urate platform for analy'ing and designing stru!tures$


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INDEX

CONTENTS PAGENO

Chapter 1? Introduction

1$1 @arly modern and the industrial age

1$1$1 >odern ar!hite!ture

1$, Statement of the pro:e!t

1$2 iterature re&ie

1$2$1 >ethod of fle7iility !oeffi!ients

1$2$, Slope displa!ement e=uations

1$2$2 anis method

1$2$4 Appro7imate method

1$4 Design of multistoried residential uilding

1$4$1 imit state method

Chapter 2: Softare!"

,$1 Staad

,$1 Alternati&es for staad

,$, Staad editor

,$2 Staad foundation

,$, Auto !ad

Chapter #: P$an and E$e%ation

2$1 Plan


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2$, @le&ation

Chapter & : 'oadin("

4$1 oad !onditions and stru!tural system response

4$, Building loads !ategori'ed y orientation

4$,$1 ori'ontal (lateral) loads

4$,$, Certi!al loads

4$,$2 ateral loads

4$2 Stru!tural systems

4$4 Design loads for residential uildings

4$4$1 Dead loads

4$4$, i&e loads

4$4$2 .ind loads

4$4$2$1 Basi! ind speed at 10 m for height for some important !itieston

4$4$4 *loor load

4$4$6 oad !ominations

Chapter ): Bea*"

6$1 Beam Design

6$1$1 Singly reinfor!ed eams

6$1$, Douly reinfor!ed !on!rete eams

6$2 #he! for the Design of a eam

Chapter + Co$u*n"


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9$1 Positioning of !olumns

9$, A7ial loaded !olumns

9$,$1 A7ial load and unia7ial ending

9$,$, A7ial load and ia7ial ending

9$2 #olumn design

9$4 3utputs

9$6 #he! the Design of a !olumn

Chapter ,- S$a."

;$1 Design of sla

;$, >anual !al!ulations

Chapter /: 0ootin("

8$1 *oundation design

8$, Dimensions and reinfor!ement details of all the footings

eferen!e and #on!lusions


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A""u*ption" and Notation" u"ed:

The notations adopted throughout the or are same "S-469-,000$

A""u*ption" in De"i(n:

1$ Esing partial safety fa!tor for loads in a!!ordan!e ith !lause 29$4 of "S-469-,000 as ϒ tF1$6

,$Partial safety fa!tor for material in a!!ordan!e ith !lause 29$4$, is "S-469-,000 is taen as 1$6

for !on!rete and 1$16 for steel$

2$ Esing partial safety fa!tors in a!!ordan!e ith !lause 29$4 of "S-469-,000 !omination of

load$

D$+$$ 1$6

D$+$+.$ 1$,

Den"it of *ateria$" u"ed:

ATERIA': DENSIT3

i) Plain !on!rete ,4$0m2

ii) einfor!ed ,6$0m2

iii) *looring material (!$m) ,0$0m2

i&)Bri! masonry 1


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DESIGN CONSTANTS:

Esing >20 and *e 416 grade of !on!rete and steel for eams% slas% footings% !olumns$

Therefore?-

f ! F #hara!teristi! strength for >20-20mm,

f yF #hara!teristi! strength of steel-416mm,

A""u*ption" Re(ardin( De"i(n:

i) Sla is assumed to e !ontinuous o&er interior support and partially fi7ed on edges%

due to monolithi! !onstru!tion and due to !onstru!tion of alls o&er it$

ii) Beams are assumed to e !ontinuous o&er interior support and they frame in to the !olumn atends$

A""u*ption" on de"i(n:-

1) >,0grade is used in designing unless spe!ified$

,) Tor steel *e 416 is used for the main reinfor!ement$

2) Tor steel *e 416 and steel is used for the distriution reinfor!ement$

4) >ild steel *e ,20 is used for shear reinfor!ement$


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S*.o$":

The folloing symols has een used in our pro:e!t and its meaning is !learly mentioned

respe!ti&e to it?

A HArea

Ast - Area of steel

- Breadth of eam or shorter dimension of re!tangular !olumn

D -3&erall depth of eam or sla

D -Dead load

d1 -effe!ti&e depth of sla or eam

D - o&erall depth of eam or sla

>u%ma7 -moment of resistan!e fa!tor

*! -!hara!ters ti! !ompressi&e strength

*y -!hara!teristi! strength of steel

d -de&elopment length

-li&e load

7 -length of shorter side of sla

y - length of longer side of sla

B$>$ -ending moment

>u -fa!tored ending moment

>d -design moment

>f -modifi!ation fa!tor

>7 -mid span ending moment along short span


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>y - mid span ending moment along longer span

>7 -support ending moment along short span

>y - support ending moment along longer span

pt -per!entage of steel

. -total design load

.d -fa!tored load

T! ma7 -ma7imum shear stress in !on!rete ith shear

T& -shear stress in !on!rete

T& -nominal shear stress

ɸ -diameter of ar

Pu -fa!tored a7ial load

>u%lim -limiting moment of resistan!e of a se!tion ithout !ompression reinfor!ement

>u7%>uy -moment aout I and J a7is due to design loads

>u71%>uy1 ma7imum unia7ial moment !apa!ity for an a7ial load of pu%ending moment 7 and J

a7is respe!ti&ely

A! - area of !on!reteK

As! -area of longitudinal reinfor!ement for !olumn


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C4APTER 1

INTROD5CTION

Building !onstru!tion is the engineering deals ith the !onstru!tion of uilding su!h asresidential houses$ "n a simple uilding !an e define as an en!lose spa!e y alls ith roof%

food% !loth and the asi! needs of human eings$ "n the early an!ient times humans li&ed in

!a&es% o&er trees or under trees% to prote!t themsel&es from ild animals% rain% sun% et!$ as the

times passed as humans eing started li&ing in huts made of timer ran!hes$ The shelters of

those old ha&e een de&eloped noadays into eautiful houses$ i!h people li&e in sophisti!ated

!ondition houses$

Buildings are the important indi!ator of so!ial progress of the !ounty$ @&ery human has

desire to on !omfortale homes on an a&erage generally one spends his to-third life times in

the houses$ The se!urity !i&i! sense of the responsiility$ These are the fe reasons hi!h are

responsile that the person do utmost effort and spend hard earned sa&ing in oning houses$

oadays the house uilding is ma:or or of the so!ial progress of the !ounty$ Daily

ne te!hni=ues are eing de&eloped for the !onstru!tion of houses e!onomi!ally% =ui!ly and

fulfilling the re=uirements of the !ommunity engineers and ar!hite!ts do the design or%

planning and layout% et!% of the uildings$ Draughtsmen are responsile for doing the draingors of uilding as for the dire!tion of engineers and ar!hite!ts$ The draughtsman must no

his :o and should e ale to follo the instru!tion of the engineer and should e ale to dra

the re=uired draing of the uilding% site plans and layout plans et!% as for the re=uirements$

A uilding frame !onsists of numer of ays and storey$ A multi-storey% multi-paneled

frame is a !ompli!ated stati!ally intermediate stru!ture$ A design of $# uilding of G+10 storey

frame or is taen up$

The design is made using softare on stru!tural analysis design (staad-pro)$ The uildingsu:e!ted to oth the &erti!al loads as ell as hori'ontal loads$ The &erti!al load !onsists of dead

load of stru!tural !omponents su!h as eams% !olumns% slas et! and li&e loads$ The hori'ontal

load !onsists of the ind for!es thus uilding is designed for dead load% li&e load and ind load

as per IS /,)$ The uilding is designed as to dimensional &erti!al frame and analy'ed for the

ma7imum and minimum ending moments and shear for!es y trial and error methods as per IS


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&)+-2666$ The help is taen y softare a&ailale in institute and the !omputations of loads%

moments and shear for!es and otained from this softare$

171 Ear$ *odern and the indu"tria$ a(e?

.ith the emerging noledge in s!ientifi! fields and the rise of ne materials and

te!hnology% ar!hite!ture engineering egan to separate% and the ar!hite!t egan to !on!entrate on

aestheti!s and the humanist aspe!ts% often at the e7pense of te!hni!al aspe!ts of uilding design$

>eanhile% the industrial re&olution laid open the door for mass produ!tion and !onsumption$

Aestheti!s e!ame a !riterion for the middle !lass as ornamental produ!ts% on!e ithin the

pro&in!e of e7pensi&e !raftsmanship% e!ame !heaper under ma!hine produ!tion$

Cerna!ular ar!hite!ture e!ame in!reasingly ornamental$ ouse uilders !ould use !urrent

ar!hite!tural design in their or y !omining features found in pattern oos and ar!hite!tural

:ournals$

17171 odern architecture:

The Bauhaus Dessau ar!hite!ture department from 1


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172 State*ent of pro8ect

Salient features?

Etility of uilding? residential !omple7

o of stories? G+10

Shape of the uilding? 6 APAT>@TS

o of stair!ases? 6

o$ of flats? 20

o of lifts? 4

Type of !onstru!tion? $#$# framed stru!ture

Types of alls? ri! all

Geometri! details?

Ground floor? 4m

*loor to floor height ? 2m$

eight of plinth ? 0$9m

Depth of foundation? 600mm

>aterials?

#on!rete grade ? >20

All steel grades? *e416 grade

Bearing !apa!ity of soil? 200m,


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17# 'iterature re%ie?

>ethod of analysis of statisti!ally indeterminate portal frames?

1$ >ethod of fle7iility !oeffi!ients$

,$ Slope displa!ements methods(iterati&e methods)

2$ >oment distriution method

4$ anes method

6$ !antile&er method

9$ Portal method

;$ >atri7 method

8$ STAAD Pro

17#71 ethod of f$e9i.i$it coefficient"?

The method of analysis is !omprises redu!ing the hyper stati! stru!ture to a determinate

stru!ture form y?

emo&ing the redundant support (or) introdu!ing ade=uate !uts (or) hinges$

'i*itation":

"t is not appli!ale for degree of redundan!yL2

17#72 S$ope di"p$ace*ent euation":

"t is ad&antageous hen inemati! indetermina!y Mstati! indetermina!y$ This pro!edure

as first formulated y a7le ender in 1


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'i*itation":

A solution of simultaneous e=uations maes methods tedious for manual !omputations$

This method is not re!ommended for frames larger than too ays and to storeys$ $

Iterati%e *ethod":

These methods in&ol&es distriuting the non fi7ed and moments of the stru!tural

memer to ad:a!ent memers at the :oints in order satisfy the !onditions of !ompatiility$

'i*itation" of hard cro"" *ethod:

"t presents some diffi!ulties hen applied to rigid frame espe!ially hen the frame is

sus!eptile to side say$ The method !annot e applied to stru!tures ith intermediate hinges$

17#7# ;ani!" *ethod:

This method o&er !omes some of the disad&antages of hardy !ross method$ anis

approa!h is similar to $#$> to that e7tent it also in&ol&es repeated distriution of moments at

su!!essi&e :oints in frames and !ontinues eams$ oe&er there is a ma:or differen!e in

distriution pro!ess of to methods$ $#$> distriutes only the total :oint moment at any stage

of iteration$

The most signifi!ant feature of anis method is that pro!ess of iteration is self !orre!ti&e$

Any error at any stage of iterations !orre!ted in suse=uent steps !onse=uently sipping a fe

steps error at any stage of iteration is !orre!ted in suse=uent !onse=uently sipping a fe steps

of iterations either y o&er sight of y intention does not lead to error in final end moments$

Ad%anta(e":

"t is used for side ay of frames$

'i*itation":

The rotational of !olumns of any storey should e fun!tion a single rotation &alue of

same storey$

The eams of storey should not undergo rotation hen the !olumn undergoes translation$ That is

the !olumn should e parallel$

*rames ith intermediate hinges !annot e analysis$


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App$ica.$e

Not app$ica.$e

17#7& Appro9i*ate *ethod:

Appro7imate analysis of hyper stati! stru!ture pro&ides a simple means of otaining a

=ui! Solution for preliminary design$ "t maes Some simplifying assumptions regarding

Stru!tural eha&ior so to otain a rapid solution to !omple7 stru!tures$

The usual pro!ess !omprises redu!ing the gi&en indeterminate !onfiguration to a determine

stru!tural system y introdu!ing ade=uate no of hinges$ it is possile to set!h the defle!ted

profile of the stru!ture for the gi&en loading and hen!e y lo!ate the print infle!tion

Sin!e ea!h point of infle!tion !orresponds to the lo!ation of 'ero moment in the stru!tures$ The

infle!tion points !an e &isuali'ed as hinges for the purpose of analysis$ The solution of


16/77

stru!tures is sundered simple on!e the infle!tion points are lo!ated$ The loading !ases are arising

in multistoried frames namely hori'ontal and &erti!al loading$ The analysis !arried out separately

for these to !ases$

4ori


17/77

ay$ A stru!ture is an assemlage of indi&idual elements lie pinned elements (truss

elements)%eam element %!olumn% shear all sla !ale or ar!h$ Stru!tural engineering is

!on!erned ith the planning% designing and the !onstru!tion of stru!tures$

Stru!ture analysis in&ol&es the determination of the for!es and displa!ements of thestru!tures or !omponents of a stru!ture$ Design pro!ess in&ol&es the sele!tion and detailing of

the !omponents that mae up the stru!tural system$

The main o:e!t of reinfor!ed !on!rete design is to a!hie&e a stru!ture that ill result in a safe

e!onomi!al solution$

The o:e!ti&e of the design is

1$ *oundation design

,$ #olumn design

2$ Beam design

4$ Sla design

These all are designed under limit state method

17&71 'i*it "tate *ethod:

The o:e!t of design ased on the limit state !on!ept is to a!hie&e an a!!eptaility that a

stru!ture ill not e!ome unser&i!eale in its life time for the use for hi!h it is intended$ "$e$ it

ill not rea!h a limit state$ "n this limit state method all rele&ant states must e !onsidered in

design to ensure a degree of safety and ser&i!eaility$

'i*it "tate:

The a!!eptale limit for the safety and ser&i!eaility re=uirements efore failure o!!urs is!alled a limit state$


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'i*it "tate of co$$ap"e?

This is !orresponds to the ma7imum load !arrying !apa!ity$ Ciolation of !ollapse limit

state implies failures in the sour!e that a !learly defined limit state of stru!tural usefulness has

een e7!eeded$ oe&er it does not mean !omplete !ollapse$

This limit state !orresponds to ?

a) *le7ural

) #ompression

!) Shear

d) Torsion

'i*it "tate of "ur%i%a.i$it:

this state !orresponds to de&elopment of e7!essi&e deformation and is used for !he!ing

memer in hi!h magnitude of deformations may limit the rise of the stru!ture of its

!omponents$

a) Defle!tion

) #ra!ing

!) Ciration


19/77

C4APTER 2

SO0T=ARES

This pro:e!t is mostly ased on softare and it is essential to no the details aout these

softares$

ist of softares used

1$ Staad pro(&8i)

,$ Staad foundations 6(&8i)

2$ Auto !ad

Staad pro Staad Auto Cad

0oundation"

STAAD

Staad is poerful design softare li!ensed y Bentley $Staad stands for stru!tural

analysis and design

Any o:e!t hi!h is stale under a gi&en loading !an e !onsidered as stru!ture$ So first

find the outline of the stru!ture% here as analysis is the estimation of hat are the type of loadsthat a!ts on the eam and !al!ulation of shear for!e and ending moment !omes under analysis

stage$ Design phase is designing the type of materials and its dimensions to resist the load$ This

e do after the analysis$


20/77

To !al!ulate S$*$D and B$>$D of a !omple7 loading eam it taes aout an hour$ So hen it

!omes into the uilding ith se&eral memers it ill tae a ee$ Staad pro is a &ery poerful

tool hi!h does this :o in :ust an hours staad is a est alternati&e for high rise uildings$

o a days most of the high rise uildings are designed y staad hi!h maes a

!ompulsion for a !i&il engineer to no aout this softare$

This softare !an e used to !arry ##% Steel% Bridge% Truss et! a!!ording to &arious !ountry

!odes$

271 A$ternati%e" for "taad:

Struts% root% sap% adds pro hi!h gi&es details &ery !learly regarding reinfor!ement and

manual !al!ulations$ But these softares are restri!ted to some designs only here as staad !an

deal ith se&eral types of stru!ture$

272 Staad Editor:

Staad has &ery great ad&antage to other softares i$e$% staad editor$ Staad editor is the

programming for the stru!ture e !reated and loads e taen all details are presented in

programming format in staad editor$ This program !an e used to analy'e another stru!ture also

y :ust maing some modifi!ations% ut this re=uire some programming sills$ So load !ases

!reated for a stru!ture !an e used for another stru!ture using staad editor$

'i*itation" of Staad pro:

1$ uge output data

,$ @&en analysis of a small eam !reates large output$

2$ Enale to sho plinth eams$

27# Staad foundation:

Staad foundation is a poerful tool used to !al!ulate different types of foundations$ "t is

also li!ensed y Bentley softares$ All Bentley softares !ost aout 10 la!s and so all

engineers !ant use it due to hea&y !ost$


21/77

Analysis and design !arried in Staad and post pro!essing in staad gi&es the load at

&arious supports$ These supports are to e imported into this softare to !al!ulate the footing

details i$e$% regarding the geometry and reinfor!ement details$

This softare !an deal different types of foundations

SA3. (DMB)

N 1$ "solated (Spread) *ooting

N,$#omined (Strip) *ooting

N 2$>at (aft) *oundation

D@@P (DLB)

N 1$Pile #ap

N ,$ Driller Pier

1$ "solated footing is spread footing hi!h is !ommon type of footing$

,$ #omined *ooting or Strap footing is generally laid hen to !olumns are &ery near to ea!h

other$

2$ >at foundation is generally laid at pla!es here soil has less soil earing !apa!ity$

4$ Pile foundation is laid at pla!es ith &ery loose soils and here deep e7!a&ations are re=uired$

So depending on the soil at type e ha&e to de!ide the type of foundation re=uired$

Also lot of input data is re=uired regarding safety fa!tors% soil% materials used should e gi&en in

respe!ti&e units$

After input data is gi&e softare design the details for ea!h and e&ery footing and gi&esthe details regarding

1$ Geometry of footing

,$ einfor!ement


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2$ #olumn layout

4$ Graphs

6$ >anual !al!ulations

These details ill e gi&en in detail for ea!h and e&ery !olumn$

Another ad&antage of foundations is e&en after the designO properties of the memers !an e

updated if re=uired$

The folloing properties !an e updated

N #olumn Position

N #olumn Shape

N #olumn Si'e

N oad #ases

N Support ist

"t is &ery easy deal ith this softare and e dont ha&e any est alternati&e to this$

AutoCAD:

Auto#AD is poerful softare li!ensed y auto des$ The ord auto !ame from auto

des !ompany% and !ad stands for !omputer aided design$ Auto#AD is used for draing different

layouts% details% plans% ele&ations% se!tions and different se!tions !an e shon in auto !ad$

"t is &ery useful softare for !i&il% me!hani!al and also ele!tri!al engineer$

The importan!e of this softare maes e&ery engineer a !ompulsion to learn this softares$

.e used Auto#AD for draing the plan% ele&ation of a residential uilding$ .e also used

Auto#AD to sho the reinfor!ement details and design details of a stair !ase$

Auto#AD is a &ery easy softare to learn and mu!h user friendly for anyone to handle and !an

e learn =ui!ly earning of !ertain !ommands is re=uired to dra in Auto#AD$


23/77

C4APTER #

P'AN AND E'E>ATION

P'ANThe auto !ad plotting no$1 represents the plan of a g+10 uilding$ The plan !learly shos

that it is a !omination of fi&e apartments$ .e !an oser&e there is a !omination eteen ea!h

and e&ery apartments$

"t is a g+10 proposed uilding% So for 6 lo!s e ha&e 610F60 flats$

The plan shos the details of dimensions of ea!h and e&ery room and the type of room and

orientation of the different rooms lie ed room% athroom% it!hen% hall et!$$ All the fi&e

apartments ha&e similar room arrangement$

The entire plan area is aout 1100 s=$m$ There is some spa!e left around the uilding for paring

of !ars$ The plan gi&es details of arrangement of &arious furniture lie sofa% et!$

The plan also gi&es the details of lo!ation of stair !ases in different lo!s$ .e ha&e , stair !ases

for ea!h lo! and designing of stair !ase is shon in Auto#AD

"n the middle e ha&e a small !onstru!tion hi!h !onsists of four lifts and those ho ant to fly

through lift !an use this fa!ility and e no for a uilding ith more than g+4 floors should

!ompulsory ha&e lift$ So these represent the plan of our uilding and detailed e7planation of

remaining parts lie ele&ations and designing is !arried in the ne7t se!tions$

E$e%ation:

Auto#AD represents the proposed ele&ation of uilding$ "t shos the ele&ation

of a g+10 uilding representing the front &ie hi!h gi&es the o&er&ie of a uilding lo!$

The figure represents the site pi!ture of our stru!ture hi!h is taen at the site $the uilding is

a!tually under !onstru!tions and all the analysis and design or is !ompleted efore the

eginning of the pro:e!t$

This is regarding the plan and details of the site and ne7t se!tion deals ith the design part of the

uilding under &arious loads for hi!h the uilding is designed$


24/77

*igure 2$,a @le&ation of the uilding

Center $ine p$an

The elo figure represents the !enter line diagram of our uilding in staad pro$ @a!h

support represents the lo!ation of different !olumns in the stru!ture$ This stru!ture is used in

generating the entire stru!ture using a tool !alled transitional repeat and lin steps$ After using

the tool the stru!ture that is !reated !an e analy'ed in staad pro under &arious loading !ases$

Belo figure represents the seletal stru!ture of the uilding hi!h is used to !arry out the

analysis of our uilding$

All the loadings are a!ted on this seletal stru!ture to !arry out the analysis of our uilding$This is not the a!tual stru!ture ut :ust represents the outline of the uilding in staad pro$

A mesh is automati!ally !reated for the analysis of these uilding$

*igure 2$, Seletal stru!ture of the uilding


25/77

C4APTER &

'OADINGS

&71 'oad Condition" and Structura$ S"te* Re"pon"e:

The !on!epts presented in this se!tion pro&ide an o&er&ie of uilding loads and their

effe!t on the stru!tural response of typi!al ood-framed homes$ As shon in Tale% uilding

loads !an e di&ided into types ased on the orientation of the stru!tural a!tion or for!es that they

indu!e? &erti!al and hori'ontal (i$e$% lateral) loads$ #lassifi!ation of loads is des!ried in the

folloing se!tions$

&72 Bui$din( 'oad" Cate(ori


26/77

Q Soil (a!ti&e lateral pressure)

&7272 >ertica$ 'oad":

Gra&ity loads a!t in the same dire!tion as gra&ity (i$e$% donard or &erti!ally) and

in!lude dead% li&e% and sno loads$ They are generally stati! in nature and usually !onsidered a

uniformly distriuted or !on!entrated load$ Thus% determining a gra&ity load on a eam or

!olumn is a relati&ely simple e7er!ise that uses the !on!ept of triutary areas to assign loads to

stru!tural elements% in!luding the dead load (i$e$% eight of the !onstru!tion) and any applied

loads(i$e$% li&e load)$ *or e7ample% the triutary gra&ity load on a floor :oist ould in!lude the

uniform floor load (dead and li&e) applied to the area of floor supported y the indi&idual :oist$

The stru!tural designer then sele!ts a standard eam or !olumn model to analy'e earing

!onne!tion for!es (i$e$% rea!tions) internal stresses (i$e$% ending stresses% shear stresses% and a7ialstresses) and staility of the stru!tural memer or system a for eam e=uations$

The sele!tion of an appropriate analyti! model is% hoe&er no tri&ial matter% espe!ially if the

stru!tural system departs signifi!antly from traditional engineering assumptions are parti!ularly

rele&ant to the stru!tural systems that !omprise many parts of a house% ut to &arying degrees$

.ind uplift for!es are generated y negati&e (su!tion) pressures a!ting in an outard dire!tion

from the surfa!e of the roof in response to the aerodynami!s of ind floing o&er and around

the uilding$

As ith gra&ity loads% the influen!e of ind up lift pressures on a stru!ture or assemly(i$e$%

roof) are analy'ed y using the !on!ept of triutary areas and uniformly distriuted loads$ The

ma:or differen!e is that ind pressures a!t perpendi!ular to the uilding surfa!e (not in the

dire!tion of gra&ity) and that pressures &ary a!!ording to the si'e of the triutary area and its

lo!ation on the uilding% parti!ularly pro7imity to !hanges in geometry (e$g$% ea&es% !orners% and

ridges)$@&en though the ind loads are dynami! and highly &ariale% the design approa!h is

ased on a ma7imum stati! load (i$e$% pressure) e=ui&alent$ Certi!al for!es are also !reated yo&erturning rea!tions due to ind and seismi! lateral loads a!ting on the o&erall uilding and its

lateral for!e resisting systems% @arth=uaes also produ!e &erti!al ground motions or a!!elerations

hi!h in!rease the effe!t of gra&ity loads$ oe&er% Certi!al earth=uae loads are usually

!onsidered to e impli!itly addressed in the gra&ity load analysis of a light-frame uilding$


27/77

&727# 'atera$ 'oad":

The primary loads that produ!e lateral for!es on uildings are attriutale to for!es

asso!iated ith ind% seismi! ground motion% floods% and soil$ .ind and seismi! lateral loads

apply to the entire uilding$ ateral for!es from ind are generated y positi&e ind pressureson the indard fa!e of the uilding and y negati&e pressures on the leeard fa!e of the

uilding% !reating a !omined push and-pull effe!t$ Seismi! lateral for!es are generated y a

stru!tures dynami! inertial response to !y!li! ground mo&ement$

The magnitude of the seismi! shear (i$e$% lateral)load depends on the magnitude of the

ground motion% the uildings mass% and the dynami! stru!tural response !hara!teristi!s(i$e$%

dampening% du!tility %natural period of &iration %et!)$for houses and other similar lo rise

stru!tures% a simplified seismi! load analysis employs e=ui&alent stati! for!es ased onfundamental etonian me!hani!s(*Fma) ith somehat su:e!ti&e(i$e$% e7perien!e-ased)

ad:ustments to a!!ount for inelasti!% du!tile response !hara!teristi!s of &arious uilding systems$

*lood loads are generally minimi'ed y ele&ating the stru!ture on a properly designed

foundation or a&oided y not uilding in a flood plain$

ateral loads from mo&ing flood aters and stati! hydrauli! pressure are sustantial$ Soil

lateral loads apply spe!ifi!ally to foundation all design% mainly as an Rout-of-plane ending

load on the all$ ateral loads also produ!e an o&erturning moment that must e offset y thedead load and !onne!tions of the uilding$ Therefore% o&erturning for!es on !onne!tions

designed to restrain !omponents from rotating or the uilding from o&erturning must e

!onsidered$

Sin!e ind is !apale of the generating simultaneous roof uplift and lateral loads% the uplift

!omponent of the ind load e7a!erates the o&erturning tension for!es due to the lateral

!omponent of the ind load$ #on&ersely the dead load may e suffi!ient to offset the

o&erturning and uplift for!es as is the !ase in loer design ind !onditions and in many seismi!design !onditions$

&7# Structura$ ""te*":

As far a! as 1


28/77

appli!ale(BS%1ore spe!ifi!ally% the BS do!ument en!ourages the use of more

ad&an!ed methods of stru!tural analysis for homes$ Enfortunately% the study in =uestion and all

suse=uent studies addressing the topi! of system performan!e in housing ha&e not led to the

de&elopment or appli!ation of any signifi!ant impro&ement in the !odified design pra!ti!e as

applied to housing systems$

This la! of appli!ation is partly due to !onser&ati&e nature of the engineering pro!ess and partly

due to diffi!ulty of translating the results of narroly fo!used stru!tural systems studies to

general design appli!ations$ Sin!e this do!ument is narroly s!oped to address residential

!onstru!tion% rele&ant system

Based studies and design information for housing are dis!ussed% referen!ed% and applied as

appropriate$ "f a stru!tural memer is part of system% as it typi!ally the !ase in light frameresidential !onstru!tion% its response is altered y the strength and stiffness !hara!teristi!s of the

system as a hole$

"n general% system performan!e in!ludes to asi! !on!epts non as load sharing and

!omposite a!tion$ oad sharing is found in repetiti&e memer systems(i$e$% ood framing) and

refle!ts the aility of the load on one memer to e shared y another or% in the !ase of a

uniform load% the aility of some of the load on a eaer memer to e !arried y ad:a!ent

memers$ #omposite a!tion is found in assemlies of !omponents that% hen !onne!ted to oneanother% from a R!omposite memer ith greater !apa!ity and stiffness than the sum of the

!omponent parts$

oe&er% the amount of !omposite a!tion in a system depends on the manner in hi!h the

&arious elements are !onne!ted$ The aim is to a!hie&e a higher effe!ti&e se!tion modulus than

the !omponent memers are taen separately$ *or e7ample% hen floor sheathing is nailed and

glued to floor :oists% the floor system reali'es a greater degree of !omposite a!tion than a floor

ith sheathing that is merely nailedO the adhesi&e eteen !omponents helps pre&ents shear

slippage% parti!ularly if a rigid adhesi&e is used$ Slippage due to shear stresses transferred

eteen the !omponent parts ne!essitates !onsideration of partial !omposite a!tion% hi!h

depends on the stiffness of an assemlys !onne!tions$ Therefore% !onsideration of the floor

system of fully !omposite T-eams may lead to an un!onser&ati&e solution$


29/77

.hereas the typi!al approa!h of only !onsidering the floor :oist memer ithout

!omposite system effe!t ill lead to a !onser&ati&e design$ This guide addresses the strength

enhan!ing effe!t of sharing and partial !omposite a!tion hen information is a&ailale for

pra!ti!al design guidan!e$ @stalishment of repetiti&e memer in!rease fa!tors (also !alled

system fa!tors) for general design use is a diffi!ult tas e!ause the amount of system effe!t !an

&ary sustantially depending on system assemly and materials$

Therefore% system fa!tors for general design use are ne!essarily !onser&ati&e to !o&er

road !onditions$ Those that more a!!urately depi!t system effe!ts also re=uire a more e7a!t

des!ription of and !omplian!e ith spe!ifi! assemly details and material spe!ifi!ations$ "t

should e re!ogni'ed hoe&er that system effe!ts do no t only affe!t the strength and stiffness

of light-frame assemlies(in!luding alls% floors and roofs)$They also alter the !lassi!al

understanding of ho loads are transferred among the &arious assemlies of a !omple7 ood

framed home$ *or e7ample% floor :oists are sometimes douled under non load-earing partition

alls Re!ause of the added dead load and resulting stresses determined in a!!ordan!e ith

a!!epted engineering pra!ti!e$

Su!h pra!ti!e is ased on a !onser&ati&e assumption regarding a load path and the

stru!tural response$ That is% the partition all does !reate an additional load% ut the partition

all is relati&ely rigid and a!tually a!ts as a deep eam% parti!ularly hen the top and ottom are

atta!hed to the !eiling and floor framing% respe!ti&ely$ As the floor is loaded and defle!ts% the

interior all helps resist the load$ 3f !ourse% the magnitude of effe!t depends on the all

!onfiguration (i$e$% amount of openings) and other fa!tor$ The ao&e e7ample of !omposite

a!tion due to the intera!tion of separate stru!tural systems or suassemlies points to the

impro&ed stru!tural response of the floor system su!h that it is ale to !arry more dead and li&e

than if the partition all ere asent $on hole-house assemly test has demonstrated this effe!t

(urst%1


30/77

At this point% the readership should !onsider that the response of a stru!tural system% ot :ust its

indi&idual elements% determines the manner in hi!h a stru!ture distriutes and resists hori'ontal

and &erti!al loads$ *or ood framed systems% the departure from !al!ulations ased are !lassi!al

engineering me!hani!s (i$e$% single memers ith standard triutary areas and assumed elasti!

eha&ior) and simplisti! assumptions regarding load path !an e sustantial

&7& De"i(n $oad" for re"identia$ .ui$din(":

Genera$

oads are a primary !onsideration in any uilding design e!ause they define the nature

and magnitude of ha'ards are e7ternal for!es that a uilding must resist to pro&ide a reasonale

performan!e(i$e$% safety and ser&i!eaility )throughout the stru!tures useful life$ The anti!ipated

loads are influen!ed y a uildings intended use (o!!upan!y and fun!tion)% !onfiguration (si'e

and shape)and lo!ation(!limate and site !onditions)$Eltimately% the type and magnitude of design

loads affe!t !riti!al de!isions su!h as material !olle!tion% !onstru!tion details and ar!hite!tural

!onfiguration$

Thus% to optimi'e the &alue (i$e$% performan!e &ersus e!onomy) of the finished produ!t% it

is essential to apply design loads realisti!ally$ .hile the uildings !onsidered in this guide are

primarily single-family deta!hed and atta!hed dellings% the prin!iples and !on!epts related

to uilding loads also apply to other similar types of !onstru!tion% su!h as lo-rise apartment uildings$ "n general% the design loads re!ommended in this guide are ased on appli!ale

pro&isions of the AS#@ ; standard->inimum Design Oloads for uildings and other stru!tures

(AS#@%1


31/77

uildings methods for determining design loads are !omplete yet tailored to typi!al residential

!onditions$ as ith any design fun!tion% the designer must ultimately understand and appro&e the

loads for a gi&en pro:e!t as ell as the o&erall design methodology% in!luding all its inherent

strengths and eaness$

Sin!e uilding !odes tend to &ary in their treatment of design loads the designer should%

as a matter of due diligen!e% identify &arian!es from oth lo!al a!!epted pra!ti!e and the

appli!ale !ode relati&e to design loads as presented in this guide% e&en though the &arian!es may

e !onsidered te!hni!ally sound$ #omplete design of a home typi!ally re=uires the e&aluation of

se&eral different types of materials$ Some material spe!ifi!ations use the alloale stress design

(ASD) approa!h hile others use load and resistan!e fa!tor design (*D)$

&7&71 Dead 'oad":

Dead loads !onsist of the permanent !onstru!tion material loads !ompressing the roof%

floor% all% and foundation systems% in!luding !laddings% finishes and fi7ed e=uipment$ Dead

load is the total load of all of the !omponents of the !omponents of the uilding that generally

do not !hange o&er time% su!h as the steel !olumns% !on!rete floors% ri!s% roofing material et!$

"n staad pro assignment of dead load is automati!ally done y gi&ing the property of the memer$

"n load !ase e ha&e option !alled self eight hi!h automati!ally !al!ulates eights using the

properties of material i$e$% density and after assignment of dead load the seletal stru!ture loosred in !olor as shon in the figure$

*ig 4$4$1a @7ample for !al!ulation of dead loadO

Dead load !al!ulation

.eightFColume 7 Density

Self eight floor finishF0$1,,6+1F2nm,

The ao&e e7ample shos a sample !al!ulation of dead load$

Dead load is !al!ulated as per IS /,) part 1


32/77

&7&72 'i%e 'oad":

i&e loads are produ!ed y the use and o!!upan!y of a uilding$ oads in!lude those

from human o!!upants% furnishings% no fi7ed e=uipment% storage% and !onstru!tion and

maintenan!e a!ti&ities$ As re=uired to ade=uately define the loading !ondition% loads are presented in terms of uniform area loads% !on!entrated loads% and uniform line loads$ The

uniform and !on!entrated li&e loads should not e applied simultaneously n a stru!tural

e&aluation$ #on!entrated loads should e applied to a small area or surfa!e !onsistent ith the

appli!ation and should e lo!ated or dire!ted to gi&e the ma7imum load effe!t possile in

endues !onditions$ *or e7ample% the stair load of 200 pounds should e applied to the !enter of

the stair tread eteen supports$

"n staad e assign li&e load in terms of E$D$ $e has to !reate a load !ase for li&e load andsele!t all the eams to !arry su!h load$ After the assignment of the li&e load the stru!ture appears

as shon elo$

*or our stru!ture li&e load is taen as 2) N** for design$

i&e loads are !al!ulated as per IS /,) part 2

*ig 4$4$,a diagram of li&e load

&7&7# =ind $oad":

"n the list of loads e !an see ind load is present oth in &erti!al and hori'ontal loads$

This is e!ause ind load !auses uplift of the roof y !reating a negati&e (su!tion) pressure on

the top of the roof


33/77

*ig 4$4$2a a diagram of ind load

.ind produ!es non stati! loads on a stru!ture at highly &ariale magnitudes$ The &ariation in

pressures at different lo!ations on a uilding is !omple7 to the point that pressures may e!ome

too analyti!ally intensi&e for pre!ise !onsideration in design$ Therefore% ind load spe!ifi!ations

attempt to amplify the design prolem y !onsidering asi! stati! pressure 'ones on a uilding

representati&e of pea loads that are liely to e e7perien!ed$ The pea pressures in one 'one for

a gi&en ind dire!tion may not% oe&er% o!!ur simultaneously in other 'ones$ *or some

pressure 'ones% the pea pressure depends on an arro range of ind dire!tion$ Therefore% the

ind dire!tionality effe!t must also e fa!tored into determining ris !onsistent ind loads on

uildings$"n fa!t% most modern ind load spe!ifi!ations tae a!!ount of ind load dire!tionality

and other effe!ts in determining nominal design loads in some simplified form(s!!i%1


34/77

o&er the surfa!e of a uilding$ .ind load star !onsidered at to different s!ales$ on

large s!ale% the load produ!ed on the o&erall uilding are on ma:or stru!tural systems that sustain

ind loads from more than one surfa!e of uilding% are !onsidered the main ind for!e

resisting systems (>.*S)$the >.*S of a home in!ludes the shear alls% Diaphragms that

!reate the lateral for!e resisting systems (*S)$As ell as the stru!tural systems su!h as trusses

that e7perien!e loads from to surfa!es are regimes of the uilding$

The ind loads applied to the >.*S a!!ount for the large affe!ts of time &arying ind

pressures on the surfa!e are surfa!es of the uilding$ 3n a Smaller s!ale% pressures are somehat

greater on lo!ali'ed surfa!e area of the uilding% parti!ularly near arupt !hanges in uilding

geometry (i$e$% ea&es% ridges% and !orners)$ These higher ind pressures o!!ur on smaller areas%

parti!ularly affe!ting the loads orne y !omponents and !ladding (e$g$% sheathing% indos%

doors% purling% studs)$

The !omponents and !ladding (#K#) transfer lo!ali'ed time-&arying loads to the

>.*S% at hi!h point the loads a&erage out oth spatially and temporally sin!e% at a gi&en

time% some !omponents may eat near pea loads hile others are at sustantially less than pea$

The ne7t se!tion presents a simplified method for determining oth >.*S and #K#

ind loads$

#entury% modernism morphed into the international style% an aestheti! epitomi'ed inmany ays y the Tin Toers of e Jors orld trade !enter$

>any ar!hite!ts resisted modernism% finding it de&oid of the de!orati&e ri!hness of

ornamented styles$ Jet as the mo&ement lost influen!e in the late 1odernism$ oert &entures !ontention that a

Rde!orated shed (an ordinary uilding hi!h is fun!tionally designed inside and emellished on

the outside) as etter than a RDu! (a uilding in hi!h the hole form and its fun!tion are

tied together) gi&es an idea of this approa!h$

Assignment of ind speed is =uite different !ompared to remaining loads$

.e ha&e to define a load !ase prior to assignment$

After designing ind load !an e assigned in to ays


35/77

1$ #olle!ting the standard &alues of load intensities for parti!ular heights and assigning of the

loads for respe!ti&e height$

,$ #al!ulation of ind load as per IS /,) part #7

.e designed our stru!ture using se!ond method hi!h in&ol&es the !al!ulation of ind load

using ind speed$

"n yderaad e ha&e a ind speed of 46 mph for 10 m height and this &alue is used in

!al!ulation$

After the assignment of ind load the stru!ture loos as shon in figure

&7&7#71 Ba"ic ind "peed:

Gi&es asi! ind speed of "ndia% as appli!ale to 1m height ao&e means ground le&el for

different 'ones of the !ountry$ Basi! ind speed is ased on pea :ust &elo!ity a&eraged o&er a

short time inter&al of aout 2 se!onds and !orresponds to mean heights ao&e ground le&el in an

open terrain$

The ind speed for some important !itiestons is gi&en tale elo$

&7&7#72 De"i(n ind "peed:

The asi! ind speed (C) for any site shall e otained the folloing effe!ts to get

design ind

&elo!ity at any height (C') for the !hosen stru!ture$

a) is le&el

) Terrain roughness% height and si'e of the stru!ture and

!) o!al topography

"t !an e mathemati!ally e7pressed as follos?

Cs$FC 1 , 2


36/77

.here

C'F design ind speed at any height U in ms

1F proaility fa!tor (ris !oeffi!ient)

,Fterrain height and stru!ture si'e fa!tor and

2Ftopography fa!tor

figure 4$4$2$2 .ind oad

&7&7& 0$oor $oad?

*loor load is !al!ulated ased on the load on the slas$ Assignment of floor load is done

y !reating a load !ase for floor load$ After the assignment of floor load our stru!ture loos asshon in the elo figure$

The intensity of the floor load taen is? 6766#) N**2

-&e sign indi!ates that floor load is a!ting donards$

*ig 4$4$4$a Dia(ra* of f$oor $oad

&7&7) 'oad co*.ination":

All the load !ases are tested y taing load fa!tors and analy'ing the uilding in different

load !omination as per IS&)+ and analy'ed the uilding for all the load !ominations and

results are taen and ma7imum load !omination is sele!ted for the design

oad fa!tors as per IS&)+-2666

'i%e $oad Dead $oad =ind $oad

1$6 1$6 01$, 1$, 1$,

0$< 0$< 0$<.hen the uilding is designed for oth ind and seismi! loads ma7imum of oth is taen$

Be!ause ind and seismi! do not !ome at same time as per !ode$ Stru!ture is analy'ed y taing

all the ao&e !ominations$


37/77

C4APTER )

BEAS

Beams transfer load from slas to !olumns $eams are designed for ending$"n general e ha&e to types of eam? single and doule$ Similar to !olumns geometry

and perimeters of the eams are assigned$ Design eam !ommand is assigned and analysis is

!arried out% no reinfor!ement details are taen$

)71 Bea* de"i(n:

A reinfor!ed !on!rete eam should e ale to resist tensile% !ompressi&e and shear stress

indu!ed in it y loads on the eam$

There are three types of reinfor!ed !on!rete eams

1$) Singly reinfor!ed eams

,$) Douly reinfor!ed !on!rete

2$) *langed eams

)7171 Sin($ reinforced .ea*":

"n singly reinfor!ed simply supported eams steel ars are pla!ed near the ottom of the

eam here they are more effe!ti&e in resisting in the tensile ending stress$ " !antile&er eams

reinfor!ing ars pla!ed near the top of the eam% for the same reason as in the !ase of simply

supported eam$

)7172 Dou.$ reinforced concrete .ea*":

"t is reinfor!ed under !ompression tension regions$ The ne!essity of steel of !ompressionregion arises due to to reasons$ .hen depth of eam is restri!ted$ The strength a&ailaility

singly reinfor!ed eam is in ade=uate$ At a support of !ontinuous eam here ending moment

!hanges sign su!h as situation may also arise in design of a eam !ir!ular in plan$

*igure shos the ottom and top reinfor!ement details at three different se!tions$

These !al!ulations are interpreted manually$


38/77

*ig 6$,a A diagram of the reinfor!ement details of eam

The folloing figure shos the defle!tion of a !olumn$

Def$ection:

*ig 6$, A diagram of the defle!tion of a !olumn$

*ig 6$,! A diagram of the shear for!e of a !olumn$

)7# Chec for the de"i(n of a .ea* ?no7 2#6@:

Gi%en data?

#ross se!tion of eam ? 7 d F 200mm 7400 mm

Certi!al shear for!e F &u F146$


39/77

F1$,19 mm,

V& W V!

design reinfor!ement Cus F Cu- V!77d (As per !lause 40$4 of "S 469-,000)

F 146$


40/77

S& should not e more than the folloing

1$ 0$;67d F 0$;6 7 400 F 200 mm

,$ 200 mm

2$ >inimum shear reinfor!ement spa!ing F S&min

ini*u* "hear reinforce*ent:

>inimum shear reinfor!ement in the form of stirrups shall e pro&ided su!h that?

As&S& W 0$4 0$8;fy (As per !lause ,9$6$1$9 of "S 469-,000)

As& F total !ross-se!tional area of stirrup legs effe!ti&e in shear%

S& F stirrup spa!ing along the length of the memer%

F readth of the eam or readth of the e of flanged eam% and

fy F !hara!teristi! strength of the stirrup reinfor!ement in mm hi!h shall not e taen

greater than 416 mn,

S&F,7(X4)78,70$8;7416(0$47200)

F20, mm$

Pro&ided , legged 8mm 5140 mm strirrups $

en!e mat!hed ith staad output$

C4APTER +

CO'5NS


41/77

A !olumn or strut is a !ompression memer% hi!h is used primary to support a7ial

!ompressi&e loads and ith a height of at least three it is least lateral dimension$

A reinfor!ed !on!rete !olumn is said to e su:e!ted to a7ially loaded hen line of the

resultant thrust of loads supported y !olumn is !oin!ident ith the line of #$G of the !olumn "

the longitudinal dire!tion$

Depending upon the ar!hite!tural re=uirements and loads to e supported% $# !olumns

may e !ast in &arious shapes i$e$ s=uare% re!tangle% and he7agonal% o!tagonal% !ir!ular$ #olumns

of shaped or T shaped are also sometimes used in multistoried uildings$

The longitudinal ars in !olumns help to ear the load in the !omination ith the

!on!rete$ The longitudinal ars are held in position y trans&erse reinfor!ement% or lateral

inders$The inders pre&ent displa!ement of longitudinal ars during !on!reting operation and

also !he! the tenden!y of their u!ling toards under loads$

+71 Po"itionin( of co$u*n"?

Some of the guiding prin!iples hi!h help the positioning of the !olumns are as

follos?-

A) #olumns should e preferaly lo!ated at or near the !orners of the uilding and at theinterse!tion of the all% ut for the !olumns on the property line as the folloing

re=uirements some area eyond the !olumn% the !olumn !an e shifted inside along a

!ross all to pro&ide the re=uired area for the footing ith in the property line$

Alternati&ely a !omined or a strap footing may e pro&ided$

B) The spa!ing eteen the !olumns is go&erned y the lamination on spans of supported

eams% as the spanning of the !olumn de!ides the span of the eam$ As the span

of the of the eam in!reases% the depth of the eam% and hen!e the self eight of the eam and the total$

Effecti%e $en(th?

The effe!ti&e length of the !olumn is defined as the length eteen the points of

!ontra fle7ure of the u!led !olumn$ The !ode has gi&en !ertain &alues of the effe!ti&e


42/77

length for normal usage assuming ideali'ed and !onditions shon in appendi7 D of "S -

469(tale ,4)

A !olumn may e !lassified ased as follos ased on the type of loading?

1) A7ially loaded !olumn

,) A !olumn su:e!ted to a7ial load and uneasily ending

2) A !olumn su:e!ted to a7ial load and ia7ial ending$

+72 A9ia$$ $oaded co$u*n":

All !ompression memers are to e designed for a minimum e!!entri!ity of load into

prin!ipal dire!tions$ "n pra!ti!e% a truly a7ially loaded !olumn is rare %if not none7istent$

Therefore% e&ery !olumn should e designed for a minimum e!!entri!ity $!lause ,,$4 of "S !ode

@ min F (600) + D200)% su:e!ted to a minimum of ,00 mm$

.here is the unsupported length of the !olumn (see ,4$1$2 of the !ode for definition

unsupported length) and

D is the lateral dimension of the !olumn in the dire!tion under the !onsideration$

+7271 A9ia$ $oad and unia9ia$ .endin(:

A memer su:e!ted to a7ial for!e and ending shall e designed on the asis of

1) The ma7imum !ompressi&e strength in !on!rete in a7ial !ompression is taen as 0$00,

,) The ma7imum !ompressi&e strength at the highly !ompressed e7treme fier in !on!rete

su:e!ted to highly !ompression and hen there is no tension on the se!tion shall e

0$0026-0$;6 times the strain at least !ompressed e7treme fier$ Design !harts for !omined a7ial

!ompression and ending are in the form of interse!tion diagram in hi!h !ur&es for Puf ! D

&erses >uf! D, are plotted for different &alues of pf ! here p is reinfor!ement per!entage$

+7272 A9ia$ $oad and .ia9ia$ .endin(:


43/77

The resistan!e of a memer su:e!ted to a7ial for!e and ia7ial ending shall e otained

on the asis of assumptions gi&en in 28$1 and 28$, ith neutral a7is so !hosen as to satisfy the

e=uilirium of load and moment aout to ees$

Alternati&ely su!h memers may e designed y the folloing e=uation?

(>u7 >uy)Yn +(>uy >uy1)YnMF1$0

>u7K>uyFmoment aout 7 and J a7is due to design loads

>u71K>uy1Fma7imum unia7ial moment !apa!ity for an a7ial load of Pu ending aout 7 and

ya7is respe!ti&ely$

Yn is related to Pupu'

pu'F0$46f!A!+0$;6fyAs!

*or &alues of puPu'F0$, to 0$8% the &alues of Yn &ary linearly from 1$0 to ,$0 for &alues less

than 0$,% Yn is &alues greater than 0$8% Yn is ,$0

The main duty of !olumn is to transfer the load to the soil safely$ #olumns are designed for

!ompression and moment$ The !ross se!tion of the !olumn generally in!reases from one floor to

another floor due to the addition of oth li&e and dead load from the top floors$ Also the amount

if load depends on numer of eams the !olumns is !onne!ted to$ As eam transfer half of the

load to ea!h !olumn it is !onne!ted$

+7# Co$u*n de"i(n:

A !olumn may e defined as an element used primary to support a7ial !ompressi&e loads

and ith a height of a least three times its lateral dimension$ The strength of !olumn depends

upon the strength of materials% shape and si'e of !ross se!tion% length and degree of proportional

and dedi!ational restrains at its ends$

A !olumn may e !lassify ased on deferent !riteria su!h as

1$) Shape of the se!tion

,$) Slenderness ratio (AF+D)


44/77

2$) Type of loading% land

4$) Pattern of lateral reinfor!ement$

The ratio of effe!ti&e !olumn length to least lateral dimension is released to as slenderness ratio$

"n our stru!ture e ha&e 2 types of !olumns$

N #olumn ith eams on to sides

N #olumns ith eams on three sides

N #olumns ith eams on four sides

So e re=uire three types of !olumn se!tions$ So !reate three types of !olumn se!tions and

assign to the respe!ti&e !olumns depending on the !onne!tion$ But in these stru!ture e adopted

same !ross se!tion throughout the stru!ture ith a re!tangular !ross se!tion $"n foundations e

generally do not ha&e !ir!ular !olumns if !ir!ular !olumn is gi&en it maes a !ir!le y !reating

many lines to in!rease a!!ura!y$

The !olumn design is done y sele!ting the !olumn and from geometry page assigns the

dimensions of the !olumns$ o analy'e the !olumn for loads to see the rea!tions and total loads

on the !olumn y seeing the loads design !olumn y gi&ing appropriate parameters lie

1$ >inimum reinfor!ement% ma7imum ar si'es% ma7imum and minimum spa!ing$

,$ Sele!t the appropriate design !ode and input design !olumn !ommand to all the !olumn$

2$ o run analysis and sele!t any !olumn to !olle!t the reinfor!ement details

The folloing figure shos the reinfor!ement details of a eam in staad$

The figure represents details regarding

1$ Trans&erse reinfor!ement

,$ ongitudinal reinfor!ement

The type of ars to e used% amount of steel and loading on the !olumn is represented in the

elo figure$


45/77

*ig 9$2a reinfor!ement details of a !olumn

Output:

Due to &ery huge and detailed e7planation of staad output for ea!h and e&ery !olumn e

ha&e shon a !olumn design results elo shoing the amount of load% moments% amount of

steel re=uired% se!tion adopted et!$

The main prolem ith staad is it taes all !olumns also as eams initially efore design and

!ontinue the same$ So here output of !olumn 1 hi!h is a!tually 121st eam as most of eams

are used in draing the plan$

*ig 9$2 defle!tion of !olumn

Chec for Co$u*n de"i(n :

Short a7ially oaded !olumns?

Gi&en data

f! F20 mm,

fy F416mm,

pu'F,;24

F260 dF460

Design of reinfor!ement Area?

(As per !lause 2


46/77

As!F,041$16 S=$mm$((>at!hed ith 3utput)

Design of >ain(ongitudinal) reinfor!ement?

(As per !lause ,9$6$2$1 of "S 469-,000 )

1$ The !ross se!tional area of longitudinal reinfor!ement shall not e less 0$8Z % not more

than 9Z of the gross !ross se!tional area of the !olumn$

,$ The ars shall not e less than 1, mm in diameter$

2$ Spa!ing of longitudinal ars measured along the periphery of the !olumn shall not

e7!eed 200 mm$

Pro&ided main reinfor!ement ? ,0 - 1, dia

(1$44Z% ,,91$


47/77

C4APTER ,

S'ABS

,71 S$a. de"i(n?


48/77

Sla is plate elements forming floor and roofs of uildings !arrying distriuted loads

primarily y fle7ure$

One a "$a.?

3ne ay sla are those in hi!h the length is more than ti!e the readth it !an e

simply supported eam or !ontinuous eam$

To a "$a.?

.hen slas are supported to four sides to ays spanning a!tion o!!urs$Su!h as sla are

simply supported on any or !ontinuous or all sides the defle!tions and ending moments

are !onsideraly redu!es as !ompared to those in one ay sla$

Chec":

There is no need to !he! ser&i!eaility !onditions% e!ause design satisfying the span for

depth ratio$

a$) Simply supported sla

$) #ontinuous eam


49/77

*ig ;$1$ a Diagrams of sla defle!tion in one ay and to ay slas


50/77

*olloing figures shos the load distriutions in to slas$

*ig ;$1$ A Diagram of load distriution of one ay and to ay slas


51/77

Slas are designed for defle!tion$ Slas are designed ased on yield theory

This diagram shos the distriution of loads in to slas$

*igure ;$1$! Distriution of loads in to slas$

order to design a sla e has to !reate a plate y sele!ting a plate !ursor$ o sele!t the

memers to form sla and use form sla utton$ o gi&e the thi!ness of plate as 0$1, m$ o

similar to the ao&e designs gi&e the parameters ased on !ode and assign design sla !ommand

and sele!t the plates and assign !ommands to it$ After analysis is !arried out go to ad&an!ed sla

design page and !olle!t the reinfor!ement details of the sla$

Slas are also designed as per IS&)+-2666

The folloing figure shos the monolithi! !onne!tion eteen eam% !olumn and sla

*igure ;$1$d monolithi! !onne!tion eteen eam% !olumn and sla

De"i(n of "$a." :

Si'e? 2$88m 7 2$62m


52/77

@nd !onditions for sla?

Ad:a!ent long and short sides are !ontinuous and other edges dis!ontinuous$

Assuming the thi!ness of sla as 1,0 mm$

Ca$cu$ation of $oad":

'i%e $oad:

*or residential uilding li&e load is usually taen as , s=$m$ (in a!!ordan!e ith 8;6 part "")

Dead $oad :

Self eight of sla F 17170$1,7,6 F 2$0 m,

.eight of flooring (;6mm thi!) F 17170$0067,0 F 1$0 m,

A!!idental loads F 1$0 m, F 1$0 m,

)76 m,

'i%e $oad?

i&e load is taen F ,$0 m,

Total load F , + 6$0 m,

*a!tored load F 1$67;$0 m,

Design load F 10$6 m,

Ca$cu$ation of *o*ent":

?As per Tale 1, of "S 469-,000)

Bendin( *o*ent coefficient" for "$a. :

Dead load and super imposed load

ear the middle


53/77

@nd of span +11,

At support ne7t to

@nd support -110

Positi&e ending moment at mid span F l,1,

>u F 10$67(2$88),1,

F 12$1;m

egati&e ending moment at support F -10$67(2$88),10

F 16$8m

Design ending moment F 16$8m

Ca$cu$ation of effecti%e depth:

Adopting >20 !on!rete and *e 416 steel

As per "S 469-,000(Anne7ure G)

>u%limit F0$297Iuma7d(1-0$4,Iuma7d)d,f!

F0$2970$49(1-0$4,70$48)d,720

Iuma7d F0$48

>ulimit F4$12d,

Assuming F1000mm

>u F>ulimit

d F[16$87109(4$1271000)

F91$86,mm

Adopting 8-mm dia ars as reinfor!ement

@ffe!ti&e !o&er F 16+10, F,0mm


54/77

3&er all depth F D F91$86,+,0F81$86,

Therefore pro&iding o&erall depth D F 1,0mm

@ffe!ti&e depth d F 1,0-,0F100mm

Ca$cu$ation of "tee$: (>A" @"*3#@>@T)

*orm "S 469-,000(Anne7ure G)

>u F0$8;7fy7Ast7d(1-fy7Astdf!) 16$8

F0$8;741671007Ast(1-4167Ast(10007100720)

Ast F42;$9mm,

Pro&iding minimum steel of F0$1,Z77DF144mm,

Spa!ing of 10mm dia ars F(ast71000)Ast

F(\710,71000)(4742;$9)

F1;


55/77

Spa!ing F (ast71000)Ast

F (\479,71000)144

F11 F 0$8;7fy7Ast7d(1-fy7Astdf!)

F 0$8;7416742;7100(1-42;7416(10007100720)

F 14$8,7109-mm

Shear for!e at the se!tion due to design loads

C F .1, F 10$672$88,

F ,0$2;

>1C+0 F 14$8,,0$2; +0

F 0$;,;m + 0

F;,;mm +0

d(a&ailale)Ld(re=d) safe


56/77

C4APTER /

0OOTINGS

*oundations are stru!tural elements that transfer loads from the uilding or indi&idual!olumn to the earth $"f these loads are to e properly transmitted% foundations must e designed

to pre&ent e7!essi&e settlement or rotation% to minimi'e differential settlement and to pro&ide

ade=uate safety against sliding and o&erturning$

GENERA':

1$) *ooting shall e designed to sustain the applied loads% moments and for!es and the

indu!ed rea!tions and to assure that any settlements hi!h may o!!ur ill e as nearly

uniform as possile and the safe earing !apa!ity of soil is not e7!eeded$

,$) Thi!ness at the edge of the footing? in reinfor!ed and plain !on!rete footing at the edge

shall e not less than 160 mm for footing on the soil nor less than 200mm ao&e the tops

of the pile for footing on piles$

BEARING CAPACIT3 O0 SOI':

The si'e foundation depends on permissile earing !apa!ity of soil$ The total load per

unit area under the footing must e less than the permissile earing !apa!ity of soil to the

e7!essi&e settlements$

/71 0oundation de"i(n:

*oundations are stru!ture elements that transfer loads from uilding or indi&idual !olumn

to earth this loads are to e properly transmitted foundations must e designed to pre&ent

e7!essi&e settlement are rotation to minimi'e differential settlements and to pro&ide ade=uate

safety isolated footings for multi storey uildings$ These may e s=uare re!tangle are !ir!ular in plan that the !hoi!e of type of foundation to e used in a gi&en situation depends on a numer of

fa!tors$

1$) Bearing !apa!ity of soil

,$) Type of stru!ture


57/77

2$) Type of loads

4$) Permissile differential settlements

6$) e!onomy

A footing is the ottom most part of the stru!ture and last memer to transfer the load$ "n

order to design footings e used staad foundation softare$

These are the types of foundations the softare !an deal$

Shallo (DMB)

N 1$ "solated (Spread) *ooting

N ,$#omined (Strip) *ooting

N 2$>at (aft) *oundation

Deep (DLB)

N 1$Pile #ap

N ,$ Driller Pier

The ad&antage of this softare is e&en after the analysis of staad e !an update the folloing

properties if re=uired$

The folloing Parameters !an e updated?

N #olumn Position

N #olumn Shape

N #olumn Si'e

N oad #ases

N Support ist


58/77

After the analysis of stru!ture at first e has to import the rea!tions of the !olumns from staad

pro using import utton$

After e import the loads the pla!ement of !olumns is indi!ated in the figure$

*ig 8$1a pla!ement of !olumns

After importing the rea!tions in the staad foundation the folloing input data is re=uired

regarding materials% Soil type% Type of foundation% safety fa!tors$

N Type of foundation? "S3AT@D$

N Enit eight of !on!rete?,6nm2

N >inimum ar spa!ing?60mm

N >a7imum ar spa!ing?600mm

N Strength of !on!rete?20 mm,

N Jield strength of steel?416 nmm,

N >inimum ar si'e?9mm

N >a7imum ar si'e?40mm

N Bottom !lear !o&er?60mm

N Enit eight of soil?,, nm2

N Soil earing !apa!ity?200 nm2

N >inimumlength?1000mm

N >inimum idth?1000mm

N >inimum thi!hness?600mm

N >a7imum length?1,000mm


59/77

N >a7imum idth?1,000mm

N >a7imum thi!ness?1600mm

N Plan dimension?60mm

N Aspe!t ratio?1

N Safety against fri!tion%o&erturning%sliding?0$6%1$6%1$6

After this input &arious properties of the stru!ture and !li! on design$

After the analysis detailed !al!ulation of ea!h and e&ery footing is gi&en ith plan and ele&ation

of footing in!luding the manual !al!ulation$

After the design is !omplete the !al!ulations is otained for ea!h and e&ery !olumn and a sample

!olumn !al!ulations is shon elo$

I"o$ated 0ootin( 1


60/77

*ig 8$1$a @le&ation and Plan of "solated *ooting

*ooting Geometry

*ooting Thi!ness (*t) ? 600$00 mm

*ooting ength H I (*l) ? 1000$00 mm

*ooting .idth H U (*) ? 1000$00 mm

#olumn Dimensions

Pedestal

Pedestal ength H I ? A


61/77

Pedestal .idth H U ? A

De"i(n Para*eter"

Concrete and Re.ar Propertie"

Enit .eight of #on!rete ? ,6$000 m2

Strength of #on!rete ? 20$000 mm,

Jield Strength of Steel ? 416$000 mm,

>inimum Bar Si'e ?_ 9

>a7imum Bar Si'e ? _ 40

>inimum Bar Spa!ing ? 60$00 mm

>a7imum Bar Spa!ing ? 600$00 mm

*ooting #lear #o&er (*% #) ? 60$00 mm

Soi$ Propertie" :

Soil Type ? En Drained

Enit .eight ? ,,$00 m2

Soil Bearing #apa!ity ? 200$00 m,

Soil Sur!harge ? 0$00 m,

Depth of Soil ao&e *ooting ? 0$00 mm

Entrained Shear Strength ? 0$00 mm,

S$idin( and O%erturnin( :

#oeffi!ient of *ri!tion ? 0$60

*a!tor of Safety Against Sliding ? 1$60


62/77

*a!tor of Safety Against 3&erturning ? 1$60

Design #al!ulations ?

*ooting Si'e

"nitial ength (o) F 1$00 m

"nitial .idth (.o) F 1$00 m

Eplift for!e due to uoyan!y F -0$00


63/77

@ffe!t due to adhesion F 0$00

>in$ footing area re=uired from earing pressure% Amin F P =ma7 F 6$; Go&erning oad #ase ? _ 4

Depth (D,) F 0$60 m Go&erning oad #ase ? _ 4

Area (A,) F 14$44 m,

Pre""ure" at 0our Corner


64/77

"f Au is 'ero% there is no uplift and no pressure ad:ustment is ne!essary$ 3therise% to a!!ount for

uplift% areas of negati&e pressure ill e set to 'ero and the pressure ill e redistriuted to

remaining !orners$

Summary of ad:usted Pressures at *our #orner

Ad:ust footing si'e if ne!essary$

Details of 3ut-of-#onta!t Area

("f Any)

Go&erning load !ase F A

Plan area of footing F 14$44 s=$m

Area not in !onta!t ith soil F 0$00 s=$m

Z of total area not in !onta!t F 0$00Z


65/77

Chec 0or Sta.i$it A(ain"t O%erturnin( And S$idin(

#riti!al oad #ase And The Go&erning *a!tor 3f Safety *or 3&erturning and Sliding I

Dire!tion

#riti!al oad #ase for Sliding along I-Dire!tion ? 4

Go&erning Disturing *or!e ? ,0$294

Go&erning estoring *or!e ? 21$;;9

>inimum Sliding atio for the #riti!al oad #ase ? 1$690

#riti!al oad #ase for 3&erturning aout I-Dire!tion? 4

Go&erning 3&erturning >oment ? 41$9oment ? 1,0$;49 m


66/77

>inimum 3&erturning atio for the #riti!al oad !ase? ,$8


67/77

>u MF >uma7 hen!e% safe

#he! Trial Depth against moment ($r$t$ U A A7is)

Critica$ 'oad Ca"e F)

@ffe!ti&e Depth F D-(!!+0$6do) F 0$46 m

Go&erning moment (>u) F 969$


68/77

T&M T! hen!e% "afe

#he! Trial Depth for one ay shear (Along U A7is)


Shear *or!e (S) F 6;2$ ;6

Shear Stress( (T&) F 22;$;;86


69/77

Along I A7is

Bar diameter !orresponding to ma7 ar si'e ( (d) F ,6$00 mm

As Per "S 469 ,000 #lause ,9$,$1

De&elopment ength(ld) Fdb∗0.87∗fy

4 √db F 1$ 4; m

Alloale ength(ld) F(B−b)

2−cc F 1$9 2 m

ld Lld hen!e% "afe

Along U A7is

Bar diameter !orresponding to ma7 ar si'e( (d) F ,6$00 00 mm

As Per "S 469 ,000 #lause ,9$,$1

De&elopment ength (ld) Fdb∗0.87∗fy

4 √db F 1$4; m

Alloale ength (ld) F( H −h)

2−cc F 1$98 m

ld Lld hen!e% safe

Botto* Reinforce*ent De"i(n

Along U A7is


70/77

*or moment $r$t$ I A7is (>7)

As Per "S 469 ,000 #lause ,9$6$,$1


>inimum Area of Steel (Astmin) F ,,8


71/77

F16 H +)7666 ** o7c7

Along I A7is

*or moment $r$t$ U A7is (>')

As Per "S 469 ,000 #lause ,9$6$,$1


>inimum Area of Steel (Astmin) F ,,8inimum spa!ing alloed (Smin) F F 60$000 mm

Sele!ted spa!ing (S) F 9


72/77

The reinfor!ement is a!!epted$

Ba"ed on "pacin( reinforce*ent incre*ent pro%ided reinforce*ent i"

F16 H +)7666 ** o7c7

Top einfor!ement Design

Along U A7is

>inimum Area of Steel (Astmin) F ,,8inimum spa!ing alloed (Smin) F 60$000 mm

Sele!ted spa!ing (S) F 8,$044 mm

Smin MF S MF Sma7 and sele!ted ar si'e M sele!ted ma7imum ar si'e$$$


73/77



F/ H /67666 ** o7c7

Along I A7is

>inimum Area of Steel (Astmin) F ,,8inimum spa!ing alloed (Smin) F 60$000 mm

Sele!ted spa!ing (S) F 8,$044 mm

Smin MF S MF Sma7 and sele!ted ar si'e M sele!ted ma7imum ar si'e$$$



74/77


F/ H /67666 ** o7c7

The figure shos layout of foundations for ea!h and e&ery !olumn$

ere e !an oser&e that some of the footings !oin!ide as they are &ery near% in su!h situations

!omined(strap or !antile&er) is laid$

einfor!ement details of !olumn is shon elo


75/77

*ig 8$,$1 ele&ation of reinfor!ements


76/77

*ig 8$,$ plan of reinfor!ement


77/77

Conc$u"ion":

1$Designing using Softares lie Staad redu!es lot of time in design or$

,$Details of ea!h and e&ery memer !an e otained using staad pro$

2$All the ist of failed eams !an e 3tained and also Better Se!tion is gi&en y the softare$

4$A!!ura!y is "mpro&ed y using softare$

Reference":

1$Theory of Stru!tures y ramamrutham for literature re&ie on ani%s method

,$Theory of stru!tures y B$#$punmia for literature on moment distriution method$

2$einfor!ed !on!rete Stru!tures y a$$ :ain and $!$ punmia for design of eams% !olumns and

sla$

4$*undamentals of einfor!ed !on!rete stru!ture y $ !$ Sinha $

Code Boo"

1$"S 469-,000 !ode oo for design of eams% !olumns and slas

,$SP-19 for design of !olumns$

Documents

g+10 HIGH RISE BUILDING