Chuong 5- tin học xây dựng

Phn II- Phn mm SAP2000

271

Chng 5 Thit k

1. Gii thiu

SAP2000 c mt mdul hon chnh cho thit k cu kin b tng ct thp (BTCT) v kt cu thp. Chng trnh cho php ngi dng la chn khi to, bin i, phn tch v

thit k cc s kt cu trong cng mt giao din.

Trong chng trnh c nhiu th vin, cc tiu chun thit k, cho php thit k t ng v kim tra cc phn t thanh BTCT. Cc tiu chun c sn trong SAP2000 l : T/C ca M

ACI 1995, Canada CSA 1984 , British BSI 1985 v European CEN 1992. . .

Vic thit k da trn mt tp hp cc t hp ti trng do ngi dng khai bo. Tuy nhin, chng trnh t cung cp cc t hp mc nh cho mi tiu chun thit k.

Trong thit k ct, chng trnh tnh ton ct dc, ct ai yu cu. Tuy nhin, ngi dng

c th khai bo ct thp dc, trong trng hp s thng bo gi tr ca " capacity ratio " ca ct. H s ny cho bit ch s ca iu kin ng sut lin quan n kh nng ca ct.

Mi phn t dm, chng trnh s thit k chu un v ct ti cc tit din do ngi dng

khai bo dc theo chiu di dm.

Trong phn mm SAP2000 v mt s phn mm tnh ton kt cu quc t, nu ngi s

dng dng mt trong cc tiu chun c sn trong chng trnh xy dng m hnh v

tnh ton ni lc th c th dng cc kt qu ny thit k cu kin bng m un thit k ca phn mm. Trong trng hp, tnh ton v phn tch kt cu bng cc tiu chun

khc (cha ci t trong chng trnh) th ngi dng khng th ng dng phn mm

thit k.

Qu trnh thit k cc cu kin b tng v thp bng SAP2000 thng phi thc hin cc

giai on sau:

- Giai on 1 : Khai bo cc s liu lin quan n thit k trong qu trnh nhp d liu cho m hnh:

+ Khai bo cc h s thit ca vt liu : v d cng chu ko, nn ca b tng, ct thp . . .

+ Chn kiu phn t thit k : dm, ct, hnh dng tit din.

+ Chn t hp thit k : t hp mc nh, t hp khai bo

PDF created with pdfFactory Pro trial version www.pdffactory.com

ng dng Tin hc trong Thit k cng trnh

272

+ Chn loi thit k : b tng, thp

+ Chn tiu chun thit k : M , Canada, Europe ...

+ Chn kiu phn tch : bi ton kim tra, bi ton thit k

- Giai on 2 : Phn tch v tnh ton ni lc (Run)

- Giai on 3 : Thit k cu kin : chy m un thit k

- Giai on 4 : Xem, kim tra kt qu thit k.

Trong chng ny, v thi gian hn ch, ch trnh by chi tit thit k cu kin b tng ct

thp. Thit k thp, v c bn cng bao gm cc bc nh thit k b tng, bn c c th tham kho thm trong cc ti liu ting Anh ca SAP2000.

2. cc bc thc hin khi thit k cu kin BTCT

2.1. Khai bo cc h s thit k lin quan n vt liu

Trong qu trnh nhp d liu cho vt liu, nu ngi dng ch quan tm n kt qu phn

tch, tnh ton ni lc th khng cn nhp chnh xc gi tr cho cc h s thit k ca vt

liu. Nu cc vt liu ang khai bo s dng cho qu trnh thit k, ngi dng bt buc phi nhp cc thng s trong phn ny. i vi vt liu b tng, thc hin cc thao tc

sau:

Vo menu Define Material: chn kiu vt liu Concrete Design Property Data nhp cc tham s (hnh 5.1):

Hnh 5.1 Khai bo cc h s thit k Hnh 5.2 Khai bo cc tham s thit k ct

Trong :

+ fy :cng chu ko ca thp, tnh theo gii hn chy. V d AII c Ratt=2800 kg/cm2, nhng fy=3000 kg/cm2.



273

+ fc : cng chu nn ca b tng. Ly bng gi tr mc b tng. V d bt mc 200 ly fc=200 kg/cm2 (Ec 20/25)

+ fys : cng chu ct ca ct thp tnh theo gii hn chy.V d: AI fys= 2100

+ fcs : cng chu ct ca b tng=fc.

2.2. Chn kiu phn t thit k ( Beam, Column)

Khi khai bo cc tit din ca s kt cu, nu tit din no tham gia c phn thit k cu kin b tng th ngoi vic khai bo kch thc tit din, phi khai bo thm cc d

liu cho phn ct thp qua cc thao tc sau:

DefineFrame/Cable Section Reiforcement (hnh 5.2): Chn loi phn t thit k cho dm (Beam ) hay ct ( Column ).

Ch : vt liu kiu CONC ch chn uc tit din Ch nht, Trn cho ct v Ch

nht,ch T cho dm. Cc thng s cho tng loi nh sau:

- Beam:

+ Top =a' ( chiu dy lp bo v pha trn )

+ Bottom =a ( chiu dy lp bo v pha di )

+ Reinforcement Overrides for Ductile Beams : chiu di on ct thp dc chng ln nhau.

- Column:

Rectangular:

+ Cover to rebar Center =a ( chiu dy lp bo v tnh n tm ct thp)

+ Number bar in dir 3: S lp ct thp tnh theo phng trc 3 ca tit din

+ Number bar in dir 2: S lp ct thp tnh theo phng trc 2 ca tit din.

+ Bar size : chn din tch thanh thp

+ Check/Design : Chn mt trong hai kiu Design or Area of one bar:

Reiforcement to be Designed: bi ton thit k

Reiforcement to be checked : bi ton kim tra

Circle:

+ Cover to Rebar Center =a ( chiu dy lp bo v )

+ Number bar : s thanh b tr u nhau trong tit din trn



274

+ Check/Design : Chn mt trong hai kiu Design or Area of one bar:

Reiforcement to be Designed: bi ton thit k

Reiforcement to be checked : bi ton kim tra

2.3. Chn t hp thit k

Trong SAP2000, nu khng khai bo trc tip cc t hp dng cho thit k, chng trnh

s cho php ngi dng chn mt s t hp mc nh. Ngoi ra chng trnh cng cho

php ngi dng a vo cc t hp mong mun.

2.3.1. Khai bo cc t hp mc nh : Define Add defauft Combo Design Chn Concrete( hnh 5.3) chng trnh SAP s hin cc t hp mc nh. V d vi bi ton khai bo 4 trng hp ti trng ( 4 Load case

), SAP2000 s t a ra 12 t hp mc nh, mi t hp c s tham gia v h s t hp cho cc trng hp ti khc nhau, ph thuc vo vt liu v cc tiu chun thit k. Trn

hnh 5.4 l v d cho tn ca cc t hp mc nh t DCON1 n DCON12 v v d cch

t hp ca SAP cho t hp DCON3.

Hnh 5.3 Hnh 5.4

2.3.2. Khai bo trc tip cc t hp thit k : Cc bc thc hin: - Menu Define Load combination : khai bo cc t hp dng cho thit k b tng

(Concrete design) nh cc t hp ni lc thng thng. V d khai bo cho COM1,

COM2.

- Vo Design Select Design Combo : chn trong s cc t hp (mc nh) hoc t hp khai bo s dng cho qu trnh thit k ca Choose Cobos, nhn Add

chuyn vo hp Design Combos (hnh 5.5).



275

Hnh 5.5 Hnh 5.6

2.4. Chn loi thit k

Trong phn ny, ngi dng phi chn loi thit k l Thp hay B tng trc khi khai

bo cho cc thng tin lin quan n thit k nh t hp thit k, thay i tit din, chn

tiu chun thit k ... qua thao tc Vo Menu Design chn (Steel or Concrtete Design ) ( hnh 5.6).

2.5. .Chn tiu chun thit k

chn tiu chun thit k thao tc :

- OptionPreferenceConcrete: chng trnh s hin hp thoi nh hnh 5.7 (vi SAP2000V7.4) v hnh 5.8 (vi SAP2000V9.03). Ngi dng chn mt tiu chun

(Concrete) Design Code.

Trong hp thoi ny c th cc gi tr mc nh hoc khai bo chng vi cc

thng s:

+ Strength Reduction factors : cc h s gim bn cho un , nn , ko , ct

+ Interaction Diagram Parameters : cc tham s lin quan n biu tng tc: Curve, Point/Curve: La chn s ng cong v im kim tra trn mi ng

cong.

+ Response Spectrum ... : thit k cho trng hp nhiu gi tr ph.

. . . .



276

Hnh 5.7 SAP2000V7.4 Hnh 5.8 SAP2000V9.03

2.6. Thit k tit din

Sau khi khai bo cc bc trn, chng trnh thc hin bi ton kim tra hay thit k, thao tc :

+ Thc hin tnh ton tnh ra ni lc ( Run )

+ Bt u thit k : DesignConcrete Frame Design Start Design/ Check of Structure

+ Bi ton thit k l nhiu bi ton kim tra.

3. In v xem kt qu

Sau khi thc hin bc Design/ Check of Streucture, SAP2000 s hin kt qu nh hnh

5.9. xem cc kt qu do SAP thit k, ty mi phin bn c th truy nhp v tr lnh v

cu trc hp thoi l khc nhau. Ni chung, ngi dng c th s dng mt trong cc cch :

- Vo menu Design Display Design Information (Results Table)

Xut hin hnh 5.10, ngi dng chn Design Input xem cc d liu nhp vo cho thit k hoc chn Design Ouput xem tng loi kt qu thit k. Mi la chn a ra v sau

khi nhn OK, mn hnh ha s hin cc gi tr tng ng vi loi va chn (nh hnh

5.9).

i vi dm, cho kt qu l din tch ct thp chu ko v chu nn, i vi ct hin ton b din tch ct thp (i vi t hp thit k chnh , theo mc nh ). Dm: dng cc kt

qu ca mmen un chnh theo M33 v Ct chnh (V22) tnh . Ct: Ct c tnh cho

bi ton ko nn lch tm xin.



277

Hnh 5.9 Hnh 5.10

Khi cc gi tr thit k ca c s hin trn mn hnh ( hnh 5.9), xem thng tin chi tit hn cho mt thc th (dm, ct), nh v chut vo mt phn t v nhn chut phi,

chng trnh m hp thoi Concrete Design Information (hnh 5.11)

Hnh 5.11 Hnh 5.12

Kt qu cho bit cc thng tin v ct thp dc, thp ai trong tng mt ct. Mun xem chi

tit hn, nhn vo Detail s hin hp thoi mi ( hnh 5.12) v cho cc thng tin sau :

+ Frame ID : Tn phn t - Station ID : tn mt ct - Section ID : Tn tit din

+ Combo ID : Tn t hp dng cho thit k

+ Cc gi tr lin quan n tit din v tham s thit k ca vt liu : L, B, E, Fy, fc...

+ Cc gi tr lc dng cho thit k : PU, M2,M3 v din tch thp tng ng(Rebar area)

- Cc kt qu thit k cng c truy nhp t cu trc bng (nh trnh by k chng 3). Ngi dng cn xem thng tin vo:



278

+ DisplayShow Table Design Data Concrete FrameOK s hin hp thoi nh hnh 5.13, ngi dng c th chn tip loi v kiu thng tin mun hin, in cho tng bng .Cc bng ny c nhiu ct, xem ht cc thng tin, dng cc thanh

trt di chuyn theo phng dc v ngang mn hnh hoc xut ra (qua chc nng

file v Format).

- Ngi dng cng c th thay i cc tham s trong qu trnh thit k qua chc nng Reset to Previous Value hoc :

+ Redefine: chn li thng tin thit k

+ Reset Design Section: Ly li tit din ban u

+ Update Analysis Section: Ly cc tit din thay i lm tit din tnh ni lc.

+ Khi tnh ct, nn s dng P-Delta kim tra iu kin n nh ca ct.

Hnh 5.13


Chuong 5- tin học xây dựng

Documents

Transcript of Chuong 5- tin học xây dựng