DESIGN BRIEF
SECURI TYPAPERSLI MI TED Co ns t r uc t i o no fRe s i de nt i a lApa r t me nt sa tJ i nna hAv e nue , Ka r a c h i STRUCTUR URAL ALDESI GN BRI EF 1 . 0
DESI GN CRI TERI A
SOFPRACTI CE 1 . 1 CODESO
Thedesi gn andspeci ficat i onsofwo workshal lbei naccordancewi wi t hal lappl i cabl e l aws wsandr egul at i onsoft hel ocalRegul at oryAut hori t y,andt heappl i cabl eCodes andSt andar ds.A summar yoft heCodesandI ndust rySt andar dst obeusedi nt he desi gnandconst ruct i oni sasunder :
Speci ficat i ons f or mat er i al s wi l l gener al l y f ol l ow t he st andar d speci ficat i onsoft heAm Amer i canSoci et yf orTest i ngandMat er i al s( ASTM)or t her el evantBri t i shSt andards. Fi el dandl abor at oryt est i ngpr ocedur esf orma mat eri al swi wi l lf ol l ow st andard ASTM/BSspeci ficat i ons. Desi gnandpl aceme mentofst ruct ur alconcr et ewi wi l lf ol l ow t her ecomm mmended pr act i cesoft he2005orl at erver si on oft heCodebyAmer i canConcr et e I nst i t ut e( ACI ) ;t heI nt ernat i onalConf erenceofBui l di ngOffici al ’ sUni f or m Bui l di ngCode1997Edi t i on( UBC1997) . Ot herr ecogni zed st andar dswi l lbe used where r equi r ed t o ser ve as gui del i nesf ort hedesi gn,f abri cati on,andconst ruct i on.
1 . 2 MATERI ALPROP OPERTI ES
a)Cyl i nders t rengt hofconcr et e,f c' Col umns,St ruct ur alWal l s Beams,Sl abs&ot herRCmember s
4. 0 ksi 4. 0 ksi
b) Densi t yofr ei nf orc edconcr et e,wc
150pcf
c) St eelRei nf or cement ,f y
60 ksi
1 . 3 WI ND LOADS DS
1. 3. 1 Thedes i gnwi ndspeedwi l lbe90mi l esperhourf ora50yearr ecur r encei nt er val . Thi sdesi gnwi ndspeedwi l lbeusedt odet er mi newi wi ndl oadsf oral lst r uct ur es.
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DESIGN BRIEF
1. 3. 2 ExposureType 1 . 4 SEI SMI CLOADS
AsperSect i on1616–UBC97 ASPER UBC97
1. 4. 1 Sei smi cDesi gnPar amet er s
Sei smi cZone Sei smi cZoneFact or ,Z Soi lPr ofil eType OccupancyCat egor y I mpor t anceFact or ,I Over st r engt hFact or Sei smi cCoeffici ent ,Ca Sei smi cCoeffici ent ,Cv
=2B =0. 2 Tabl e16–I AsperGeoTechI nvest i gat i on Tabl e16–K Tabl e16K Tabl e16–N Tabl e16–Q Tabl e16–R
1 . 5 CRACKEDSECTI ON PROPERTI ESASSUMED FORDESI GN
1. 5. 1 Modul usofEl ast i ci t y:Ec=wc1. 533√f c’( psi ) ( UBC97Sect i on1908. 5. 1) 1. 5. 2 Cr ac kedMoment sofI ner t i a: ( UBC97Sect i on1910. 11. 1) Beams 0. 35I g Col umns 0. 70I g Wal l s 0. 35/0. 70I g Sl abs 0. 25I g 1. 5. 3 Ar ea 1. 0Ag Theaboveval uesmaybemodi fiedasperdes i gncondi t i ons. 1 . 6 DEF LECTI ON CRI TERI A
AsperUBC97( Tabl e19C2) :Cont r olofi mmedi at eandl ongt er m deflect i onst o pr eventi mmedi at eandl ongt er m damaget ononst r uct ur alel ement sat t achedt o t hest ruct ure. 1 . 7 DURABI LI TY
Mi ni mum concr et ecovert ot henearestr ei nf orcement( i ncl udi ngl i nks)shal lbeas f ol l ows: RCSl abs 1i n RCBeams 1½i n Page 2 of 5
DESIGN BRIEF
Col umns Wal l s( ot hert hanbas ementr et ai ni ngwal l s) : Raf tFoundat i on 2 . 0
1½i n 1½i n 2i n
STRUCTURAL SYSTEMS
ON SYSTEM 2 . 1 FOUNDATI
Type off oundat i on shal lbe sel ec t ed bas ed on t he r ec ommendat i on s of Geot echni calI nvest i gat i onRepor t . Aneffici entf oundat i onsyst em wi l lbeanal yzedusi ngt hefini t eel ementcomput er sof t war e“SAFE”. 2 . 2 FLOORSYSTEM
Techni cal& costeval uat i onsofvari ousal t er nat i ve st r uct ur als chemeswi l lbe consi der ed bef oret heopt i mum st ruct ur als yst em appr opr i at et ot hepr oj ecti s final l yarr i vedat . Thecri t eri at oarr i veatt heseopt i mum st ruct ur alsyst emsareasf ol l ows. 1) Economi calbutt echni cal l yeffici entsys t em 2) Bui l dabi l i t yt omi ni mi zeconst r uct i oncostandt i me 3)Compl i anceswi t hCodesofPr act i ces 4) Aest het i cal l yaccept abl et ot hear chi t ect ur alr equi r ement s. Thepr ef er abl eopt i onsoft hefloorsyst em mayi ncl udebutnotl i mi t ed t ot he f ol l owi ngcoul dposs i bl ybeadopt ed: a) RCFl atPl at e b) RCFl atSl abwi t hdr oppanel s c) Beam and sl ab Tr adi t i onal Beam & Sl abconst r uct i on,t houghr esul t i ngi nt hi nners l absi nt he smal lpanel sbet weent hegr i l l ageofbeams,wasnotc onsi der edf easi bl eduet o poorbui l dabi l i t y( i ncr easedconst r uct i ont i me) ,andpr ovi di ngi nsuffici entr oom t oaccommodat eM&Eover headser vi ces( duet ol i mi t edfloort ofloorhei ght ) . I nt heRC Fl atPl at esyst em,t hesl absoffiti sauni f orm flatsur f acewi t houtany i nt er r upt i ons.For mwor ki s ver y si mpl e and f as tt o assembl e.Thi s scheme provi des maxi mum headroom,maxi mum servi ces flexi bi l i t y and has l eas t archi t ect ur ali mpact .However ,duet ol i mi t edt hi cknessatt hecol umns,i thasl ess Page 3 of 5
DESIGN BRIEF
r es i st ance t ot he combi ned gravi t y and sei smi c shear s needi ng i ncr eas ei n t hi ckness .Ont heot herhand,t hei ncr easedt hi ckness( wei ght )woul dat t r actmore sei smi cf orcesand woul d al so i ncr ease gravi t yl oads on t he col umns and foundations. RCFl atSl absyst em i squi t esi mi l art ot heFl atPl at esyst em exceptf ort hedr op panelovert hecol umns.Theaddi t i onalt hi cknessoft hesl abovercol umnshel psi n provi di ngi ncr easedres i st ancet oshearf or ces( gr avi t yandsei smi c) . 2 . 3 LATERALFORCERESISTING SYSTEM
Kar achil i esi n( upper )moder at esei smi czonecorr es pondi ng t oUBC Zone2B. Pr el i mi nary anal ysi sshowst hatt hesway duet o sei smi cf orcescont r ol st he st ruct ur alconfigur at i onanddesi gnoft hebui l di ng.Forpr ovi di ngadequat el at er al f or ceres i s t i ngsyst em,t wosyst emswi l lbeconsi dered: 1)DualSyst em basedonf r ameshearwal li nt er act i onandhavi ngt hef ol l owi ng t hreeessent i alf eat ures: i .Aness ent i al l ycompl et espacef r amet hatpr ovi dessupportf orgr avi t y loads, i i .Resi st ancet ol at er all oadsi spr ovi ded byshearwal l sand moment r esi st i ng f r ames.Themoment r esi st i ng f r amesshal lbecapabl et o i ndependent l yr esi statl east25% oft hedesi gnbaseshear ,and i i i .Thet wosyst ems( momentf r amesand shearwal l s)ar edes i gnedt o r esi stt hedesi gnbasesheari npr oport i ont ot hei rrel at i veri gi di t i es consi deri ngt hei nt eract i onoft hedualsyst em atal ll evel s. 2)MomentRes i st i ngFrameSyst em i saf r amei nwhi chmembersandj oi nt sar e capabl eofresi st i ngf orc espri mari l ybyflexure. Ateach floorl evel ,t hesl ab di aphr agmst r ansf ert hel at er all oadst ot he f r ames.I nSei smi cZone2B,t hemomentf r amesr esi st i ngl at er all oadsmust beI nt er medi at eMoment Resi st i ngFr ames( I MRF) . 3 . 0
Comput e rMode l i ng
A 3di mensi onalcomput ermodel ,usi ng t hefini t eel ementcomput erprogr am “ETABS”wi l lbegener at ed t osi mul at et hebui l di ng’ sgr avi t yand l at er alf orc e r es i st i ng syst em.Separ at e comput ermodel s wi l lbe cr eat ed t o moni t or t he bui l di ng’ sper f ormanceatdi ffer entst agesofconst r uct i on.Sever alanal yseswi l lbe conduct edusi ngdi ffer entmemberproper t i est ost udyt hesensi t i vi t yoft heaxi al l oad di st r i but i on t o ass umpt i onson memberpr oper t i es.I n al lc ases,cr acked flexur alpr oper t i eswi l lbeass umedf ort hebeams,col umnsandsl abs. Page 4 of 5
DESIGN BRIEF
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