L e xing to n I I Pre se nta tio n Outline a t Ma rke t Sq ua re - - PDF document

1

L e xing to n I I

a t Ma rke t Sq ua re No rth, Wa shing to n D.C. Ale xis Pa c e lla – Struc tural Optio n

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l Gra vity Syste m L a te ra l Syste m Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt Me c ha nic a l Co nc lusio n

Building Summa ry

12 Sto ry Re side ntia l T

• we r

Ma rke t Sq ua re No rth Co mple x 3 b e lo w g ra de le ve ls 72,000 sq ft 49 Apa rtme nt Units Co mple te d in 2002

Building Summa ry Pre se nta tio n Outline

Building Summa ry

E xisting Str uc tur e

Pro po sa l Gra vity Syste m L a te ra l Syste m Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt Me c ha nic a l Co nc lusio n

E xisting Struc ture

Gra vity Syste m:

2 Wa y F lat Plate Slab 8 inc he s I rre g ula r Co lumn L ayo ut Small Ba ys

L a te ra l Syste m:

She a r Wa lls

F

• unda tio n:

MAT

2

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture

Pr

• posal

Gra vity Syste m L a te ra l Syste m Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt Me c ha nic a l Co nc lusio n

Pro po sa l

Cur r e nt de sign r e str ic te d by he ight limit: 130 fe e t (c ur r e nt he ight = 125 ft w/ pe nthouse ) Only str uc tur e s with a thin floor sandwic h, suc h as flat plate and pr e -stre sse d we r e c onside r e d Whe n he ight r e str ic tion is not a fac tor ,

Can A More E c onomic Syste m be F

• und???

Pro po sa l

Ho w will a ste e l struc tura l syste m e ffe c t… Othe r b uilding syste ms T ime

COST

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l

Gr avity Syste m

L a te ra l Syste m Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt Me c ha nic a l Co nc lusio n

Gra vity Syste m

Composite :

Ste e l c o mpo site de c k o n ste e l b e a ms a nd c o lumns Re la tive ly shallo w flo o r sa ndwic h No la rg e c ha ng e in stiffne ss a nd vib ra tio n Ste e l is usually mo st c o st e ffe c tive Additio nal c o st a nd la b o r fo r fire pro o fing a nd c o nne c tio ns

Gra vity Syste m

Ne w c olumn layout r e quir e d for ste e l syste m to be e c onomic al

Doe s not inte r fe r e w/ ar c hite c tur e Windows move d One c lose t

• bstr

uc te d

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Gra vity Syste m

Composite De c king:

Spa n is to o lo ng , b ise c t e a c h b a y with a b e a m Unsho re d sa ve s o n la b o r a nd ma te ria l Unsho re d will use e xtra c o nc re te

R e side ntial L e ve ls: 2” L OK floor de c k with 4.5” slab Public L e ve ls: 3” L OK de c k with 5.5”slab

De c king c ho se n fro m USD c a ta lo g .

Be ams, c olumns, and she ar studs we r e de signe d for gr avity loads using RAM softwar e .

Gra vity Syste m

RAM c rite ria se t to L RDF 3rd E ditio n

Gra vity Syste m

F inal De sig n: 4.5” de c k + slab 12” b e a m

= 16.5” T

• tal floor

sandwic h de pth

I nc re a se o f 8.5” pe r flo o r 8.5’ to ta l Ne w He ig ht = 133.5’ > Allo wa ble 130’

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l Gra vity Syste m

L ate ral Syste m

Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt Me c ha nic a l Co nc lusio n

3 po ssible L a te ral Syste ms: She a r Wa lls Mo me nt F ra me s Bra c e d F ra me s

L

• c ate d ar
• und e le vator

shaft Ar c hite c tur al F e atur e of the building Will not obstr uc t bays Costly c onne c tions High str e ngth and stiffne ss E asy to e r e c t

L a te ra l Syste m L a te ra l Syste m

She ar Walls: Che c k E xisting Walls E T ABS R e sults: Sur r

• und E

le vator Shaft Ste e l L ighte r We ight L e ss Se ismic L

• ad

8.5’ he ight inc r e ase Slightly Gre ate r Wind L

• ad

4

Br ac e d F r ame s:

F ind lo c a tio n in b uilding Distrib ute L

• a ds b y Rig idity

Che c k ASCE 7 wind c a se s De sig n, c he c k o n ST AAD

De sign was c ontrolle d by allowable str e ss

L a te ra l Syste m L a te ra l Syste m

ST AAD De sig n: Che vro n Bra c e s Me mb e r Stre sse s Co ntro lle d Size Ra ng e : W12x65 – W12X170 T

• tal De fle c tio n < 3.6” a llo wa ble

F inal De sig n:

So me c o lumns c o ntro lle d b y b ia xia l b e nding inc re a se d size Size s: W12x65 – W14x342 F ina l De fle c tio n = 2.7” < 3.6” a llo wa b le 1 2 ≤ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ + + Mny Muy Mnx Mux Pn Pu φ φ φ

L a te ra l Syste m Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l Gra vity Syste m L a te ra l Syste m

Othe r Str uc tur al F ac tor s

Co nstruc tio n Ma na g e me nt Me c ha nic a l Co nc lusio n

Are the re o the r issue s with the struc ture to b e c o nside re d? Co nne c tio ns Sub struc ture F

• unda tio n

Othe r Struc tura l F a c to rs

Be am to Column Conne c tions:

Stiffe ne rs Re q uire d

T ypic a l 7th flo o r c o nne c tio n

Othe r Struc tura l F a c to rs

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He avy Br ac ing Conne c tion:

Unifo rm F

• rc e Me tho d

Sa me b e a m to c o lumn c o nne c tio n 27”x27”x1/ 2” g usse t pla te 3”x3”x1/ 2” a ng le s

Othe r Struc tura l F a c to rs

T ypic a l 7th flo o r c o nne c tio n

Othe r Struc tura l F a c to rs

T he Sub struc ture : Co nc re te is b e tte r in sub te rra ne a n c o nditio ns Additio na l b uilding we ig ht Co nc re te is a mo re dura ble pa rking struc ture

Othe r Struc tura l F a c to rs

Sub struc ture : One wa y jo ist flo o r ~e a sy to c o nstruc t ~wo rks with ne w b a y size s 20” pa ns; 5” rib s; 25” o .c .

Othe r Struc tura l F a c to rs

Sub struc ture : Girde rs: 24”x15” to p ste e l = 7 # 9’ s b o tto m ste e l = 4 # 8’ s

Stirrup Pla c e me nt Re info rc e me nt Cuto ffs Girde r Se c tio n

Othe r Struc tura l F a c to rs

Sub struc ture : Co lumns: Be lo w the Bra c e d F ra me s: She a r wa lls we re use d, she a r c o ntro lle d

Othe r Struc tura l F a c to rs

Sub struc ture : Co nne c tio ns ~ a b a se pla te sunk into flo o r sla b a t e a c h c o lumn

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Othe r Struc tura l F a c to rs

F

• unda tio n:

E xisting MAT fo unda tio n Punc hing she a r Ove rturning

F

• rc e s a ffe c ting
• ve rturning

No Pr

• ble ms

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l Gra vity Syste m L a te ra l Syste m Othe r Struc tura l F a c to rs

Constr uc tion Manage me nt

Me c ha nic a l Co nc lusio n

Co nstruc tio n Ma na g e me nt

Co nstruc tio n Ma na g e me nt I ssue s: Site L a yo ut Co st Sc he duling

Co nstruc tio n Ma na g e me nt

Site L a yo ut: Ne e de d spa c e s: o ffic e s, c irc ula tio n pa ths, sto ra g e , e tc … Ste e l De sig n ~ Cra ne ~ L a y Do wn Are a

Co nstruc tio n Ma na g e me nt Co nstruc tio n Ma na g e me nt

Co st : Co nc re te ......................................$1,526,000 Ste e l ………………………………...$1,455,600 Save s $70,000 T his do e s no t ho we ve r a c c o unt fo r c o st due to e xtra fa ç a de ma te rial o r fire pro o fing Building Sc ale is no t la rg e e no ug h to de ve lo p full e c o no my a sso c ia te d with a ste e l struc ture

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Co nstruc tio n Ma na g e me nt

E a c h le ve l is built in the se q ue nc e :

1 da y fo r c o lumns a nd b e a ms 2 da ys fo r de c k Ne xt le ve l is sta rte d Sla b s po ure d whe n b e a m, c o lumn, a nd de c k c o nstruc tio n is 3 sto rie s a he a d.

Sc he duling :

T

• ta l:

18 we e ks

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l Gra vity Syste m L a te ra l Syste m Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt

Me c hanic al

Co nc lusio n

Me c ha nic a l

Me c ha nic al Co nside ra tio ns: HVAC Ac o ustic s

Me c ha nic a l

HVAC: F re sh a ir re q uire me nts a re me t b y windo ws

Me c ha nic a l

HVAC: ME P Syste ms c a n b e mo ve d fro m so ffits into c e iling sa ndwic h. Be a ms sho uld no t b e inte rse c te d .

Me c ha nic a l

Supply E xha ust

8

Me c ha nic a l

Ac o ustic s: Orig inal Syste m: Co nc re te c e iling s with spra ye d a c o ustic a l se ala nt NRF = .75 Ste e l Syste m: Suspe nde d c e iling with a c o ustic a l tile s NRF = .5 to .95

Me c ha nic a l

Ac o ustic s: Ac o ustic T ile s o n suspe nde d c e iling Asse mbly I ssue s

Pre se nta tio n Outline

Building Summa ry E xisting Struc ture Pro po sa l Gra vity Syste m L a te ra l Syste m Othe r Struc tura l F a c to rs Co nstruc tio n Ma na g e me nt Me c ha nic a l

Conc lusion

Co nc lusio ns

Str uc tur al de sign was c ontr

• lle d by he ight r

e str ic tion Composite : L ar ge r Bays Wor ks we ll with othe r inte grate d syste ms F ull E c onomy of Ste e l Savings was not ac hie ve d

Que stions?