Do an ket cau thep 2

8/12/2019 Do an ket cau thep 2

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n Kt Cu Thp GVHD : Th.S. Trn Quc Hng

SVTH : Mai Xun Ton-XDLTTD12 Trang 1

MC LCPHN I: S LIU BI

1. SLIU CHUNG2. SLIU RING

PHN II: XC NH KCH THC KHUNG NGANG.

1. CU TRC2. XC NH KCH THC THEO PHNG NG3. XC NH KCH THC THEO PHNG NGANG4. XC NH KCH THC CHNH CA KHUNG NGANG

PHN III: XC NHTI TRNG TC DNG LNKHUNG NGANG.

1. TI TRNG THNG XUYN2. TI TRNG SA CHA MI3. P LC CU TRC LN VAI CT4. LC X NGANG CA CU TRC5. P LC GI

PHN IV: XC NHNI LCKHUNG NGANG.

1. TNH TI2. HOT TI3. P LC NG Dmax V Dmin4. LC X NGANG T5. TI GI

PHN V: T HP NI LC.1. BNG TM TT NI LC TRONG KHUNG2. BNG THP NI LC TRONG KHUNG

PHN VI: THIT K CT.

1. THIT KCT TRN2. THIT KCT DI3. THIT KCC CHI TIT CT4. TNH TON CHN CT

PHN VII: THIT K DN MI.

A. TNH NI LC THEO PHNG PHP GIN CRMNA1. S V KCH THC CHNH CA DN2. TI TRNG TC DNG LN DN3. TNH TON NI LC TRONG DN4. TNH TON CHN CT

B. TNH NI LC THEO PHN MM SAP 2000C. NHN XT- CHN PHNG N TNH TON THANH DND. TNH TON CC THANH DN1. XC NH CHIU DI TNH TON CC THANH DN2. CHN TIT DIN CC THANH DN3. TNH DN PHN NH4. TNH TON CC CHI TIT TRONG DN


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PHN I:

S LIU BI

1. SO LIEU CHUNG:1 a iem xay dng:

2 Quy mo cong trnh: + Nha cong nghiep mot tang, 1 nhp. Bc cot eu nhau =6m.

+ Mai dung panel ( Be rong tap mai 1.5m) lp tren dan thep. o doc mai i= 1/10

+ Cau truc hai moc, lam viec che o trung bnh

+ Vat lieu thep CT3, Que han E42A, bulong t thep o bn thuoc lp 4.6 ( hoac lp 4.8).

Mong be tong mac 300.

3 a hnh: Thuoc a hnh B ( tng oi trong trai)

2.

SO LIEU RIENG:

Sliu tnh toan :

-Nhp : L = 30 m.-Sc truc : Q = 50/10 T.-Cao trnh ray : Hr= 9.0 m.-Bc khung : B = 6 m.-Chieu dai nha : L = 84 m.-Vung gio IA q0= 55daN/m2

Q=50/10T

2200

+16.900m

15400

0.00m

-0.60m

+19.700m

+15.400m

+13.200m

+9.65m

+8.700m

30000

M? T C? T NGANG CNG TRNH TL 1/200

Q=50/10T

4500

87

00

+19.100m

3000 3000 3000 3000 3000 3000 3000 3000 3000 3000

i=10% i=10%

Nhp nha L (m) Chieu cao nh ray Hr(m) Sc trc Q (kN)

30 9.0 500/100


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PHN II:

XC NH KCH THC KHUNG NGANG

1.CU TRC:Q = 50/10T, ch bnh thng, nhp nh xng 30 m, tra bng ta c cu trc :

-Loi ry : KP-80.-Chiu cao : Hct= 3150 mm.-B rng ca cu trc : Bct= 6650 mm.-Nhp cu trc : Lct= 28.5 m.-Khong cch gia hai trc bnh xe ca cu trc : K = 5250 mm.-Kch thc t tim ry n mp ngoi : B1= 300 mm.-Pmax= 490 KN.-Pmin= 145 KN.-Gxe = 180KN.-Gct = 770 KN.2.XC NH KCH THC THEO PHNG NG :

-Cao trnh nh ray Hr= 9.0 m.-S b chn chiu cao ca ray v m : hr= 0.2 m.-Chiu cao ca dm cu trc chy :hdct=

10

1

8

1B =

10

1

8

1x 6 = (0.75 0.6) Chn hdct= 0.75 m.

-C mng bng cao trnh nn hm= 0.6mChiu cao thc ca phn ct di :

Hd= Hr+ hmhrhdct= 9.0 + 0.60.20.75 = 8.65 m.

-Chiu cao gabarit ca cu trc : H= 3.15 m.-Khe h an ton : 0.1 m.-vng ca kt cu mi : f = 0.3 (khong 1/100 nhp)

Chiu cao thc ca phn ct trn :

-Ht= hr+ hdct+ Hk+ 0.1 + f = 0.2 + 0.75 + 3.15 + 0.1 +0.3 = 4.5 m.Nh vy, lm trn ta ly : Ht= 4.5 m, Hd= 8.7 m.

3.XC NH KCH THC THEO PHNG NGANG:

-Nhp nh xng : L = 30 m.-Nhp cu trc : Lk= 28.5 m.-Kch thc phn u cu trc : B1= 0.3 m.


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-Khe h an ton gia mt cu trc v mp trong ct trn : D = 0.06 m.Khong cch t tim ray n trc nh v :

2

LL k

= 0,75 mm-Chn s b b rng phn ct trn :-ht=

11

1

10

1Ht=

11

1

10

1x 4.5= 0.45 0.409.

Ta chn ht= 0.45 m (bi s ca 0.25 m).

-Khong cch t trc nh v ti mp ct ngoi:DBha 1t = 0.45 + 0.3 + 0.060.75 = 0.06 m.

Ta chn a = 0.25 m (trc nh v trng vi tim ct trn)-B rng ct di : 125.075.0ah d m.-kim tra li theo yu cu cng ca khung -hd

11

1

10

1Hd= 0,1 m 0,09 m

-hd 1/20 (Ht+ Hd) = 0,855 m (tha yu cu )

4.XC NH KCH THC CHNH CA KHUNG NGANG:

Q=50/10T

2200

+16.900m

15400

0.00m

-0.60m

+19.700m

+15.400m

+13.200m

+9.65m+8.700m

30000

M? T C? T NGANG CNG TRNH TL 1/200

Q=50/10T

4500

8700

+19.100m

3000 3000 3000 3000 3000 3000 3000 3000 3000 3000

i=10% i=10%


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*Cu to dn:Chiu cao du dn bng 2200 (mm), dc cnh trn i=1/10

* H ging:a. H ging mi* Ging cnh trn:.

* Ging cnh d-i:

i=10% i=10%

3000 3000 3000 3000 3000 30003000300030003000

30000

2200

2200

6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000600084000

0.0

0m

-0.5

5m

30000

H? GI? NG CNH THU? NG- TL 1/500

31 2 4 6 7 98 10 1211 13 145 15

A

B

6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000600084000

0.0

0m

-0.5

5m

30000

H? GI? NG CNH H? -TL 1/500

31 2 4 6 7 98 10 1211 13 145 15

A

B


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* H ging ng:

b. H ging ct

84000

6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 60006000

H? GI? NG ? NG TL 1/500

31 2 4 6 7 98 10 1211 135 14 15

3700

2200

31 2 4 6 7 98 10 1211 135

H? GI? NG C? T TL 1/500

6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000 6000

14 15

4500

8700


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PHN III:

XC NH TI TRNG TC DNG LN KHUNG

NGANG1.TI TRNG THNG XUYN:a.Trng lng mi :

dc mi : i =10%

cos = 0.995

Trng lng do cc lpmi

Ti trng tiuchun (daN/m2)

H svt ti

Ti trng tnh ton(daN/m2)

1. Tm panen b tng ctthp c ln

150 1.1 165

2. Lp b tng nh cchnhit dy 4 cm

40 1.2 48

3. Lp chng thm 2 giy3 du

10 1.2 12

4. Lp va t trt tngchiu dy 4 cm

80 1.2 96

5. Hai lp gch l nem milp dy 3 cm

120 1.1 132

Tng ti trng 400 453

Trng lng kt cu mi v h ging c ly nh sau: g tt1= nxgtc

1= 1.2x30=36 (daN/m2)

Trng lng kt cu ca mi: gtt2= n x gtc

2= 1.2x15=18 (daN/m2)

2.TI TRNG SA CHA MI :Theo tiu chun Vit Nam v ti trng v tc ng TCVN 2737 -1995, ti trng sa cha mi lp

panen btng ct thp c ly bng 75daN/m2mt bng nh, gi thit dc mi nghing l 1/10Hay ni cch khc mi nghing 1 gc 6.Gi tr ti sa cha mi a vo tnh ton l :

pc= 75 daN/m2.

n =1.3

' c0

1.3 75p n.p 98

cos6

daN/m2.

Ti sa cha mi dn v mt khung thnh ti phn b u

P = P` * B = 98 * 6 = 588 (daN/m) = 5.88 (KN/m).


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Tnh ti tc dng ln dn :

Chn hck= 0.7 m.

Gbc+ck= 2* (165 + 44 * 0,7) / 27 = 14,50 daN/m2.

Tnh ti : )gggg.(Bg ckbcctdm = 12 x (455.27 + 21.38 + 13,2 + 14,50) = 6052,2daN/m2.

Hot ti tc dng ln ct :

P = P` * B = 105 * 6 = 1260 daN/m2.

3.P LC CU TRC LN VAI CT:p lc cu trc ln vai ct c tnh theo cng thc sau :

Dmax= n.nc.Pmax. iy

Dmin= n.nc.Pmin. iy

Vi + n=1.1 l h s vt ti

+ nc= 0.9 l h s thp, xt n xc xut xy ra ng thi ti trng ti a ca 2 cu trc hotng cng nhp.

Theo Catalogue ta c pmax= 490 KN, Pmin=145 KN

Hoc c th tnh gi tr ca pminnh sau:

Tng trng lng cu trc G=770 KN, s lng bnh xe mt bn ray n0=2.

Pmin=0

500 770 490 1452max

Q GP

nKN.

Sp xp cc bnh xe cu trc trn ng nh hng nh sau:

Y2= 1

Y3= 0,676Y1= 0.125

y4= 0

P1 P2 P3 P4

5000 1300 5000

6000 6000

Y1

Y2 Y3

1000 5000 1300 4700

300


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tnh c cc gi tr y ny ta da vo cc tam gic ng dng

1 0.125 0.676iy =1.892

Suy ra :

Dmax= m.nc.Pmax. iy =1.1x0.9x490x1.892= 917.809 (kN)

Dmin= m.nc.Pmin. iy =1.1 x0.9x145x1.892= 217.597 (kN)

4.LC X NGANG CA CU TRC:Tng lc hm tc dng ln ton cu trc l: '0 . .

xems xe

xe

Q GT f n

n

Trong :

- Q : l sc trc =500 KN- Gxe: trng lng ca xe con=180KN- nxe=4 : s bnh xe ca mt xe con- fms: lc ma st gia mc cu v cu trc ( ly bng 0.2) 0 500 180 0.2 24T x x =68 KN

Lc hm tiu chun ln mt bnh xe ca cu trc:

T1= 0

0

6834

2

T

nKN.

Vy lc x ngang ca cu trc l:

T= n.n1.T1. iy =1.1x0.9x34x1.892=63.685 KN.

Lc x ngang ny t cao trnh mt trn ca dm cu chy, cch vai ct 0.75m, lc l cao trnh9.45m.

5.P LC GI:Ti gi tc dng ln 1 khung c xc nh theo cng thc: q=n.c.k.q0.B

Trong : q0 : p luc gi tiu chun=55 daN/m2.

: n0:H s vt ti, ly bng 1.3

: C : H s kh ng

Ti gi tc dng ln khung gm 2 phn :

- Tp trung : t ti y v ko.

- Phn b : di y v ko.


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a.Ti trng tp trung ti y v ko :

Cao trnh y v ko : H = 13.2 mKb= 1.0512

Cao trnh nh v ko : H = 13.2 + 2.2 + 1.5 + 2.2 + 0.5 = 19.7 m KT= 1.127

Trong khong t cnh di dn n nh mi h s k c ly trung bnh 2 gi tr trn v bng 1.0891

Ti gi tp trung ti y v ko :

ii0 h.C.B.K.q.nw

dw 1.3 55 1.0891 6 (0.8 2.2 0.6 0.9 0.7 2.2 0.8 0,6)

dw = 1065.27 daN = 10.653 kN

hw 1.3*55*1.0891 6 (0.6 0.5 0.6 2.2 0.6 0,9 0.6 2.2)

hw = -1611.92 daN = 16.1192 kN

b. Ti trng phn b u (trn ct) :Gi y:

C.B.K.q.nq 0

q 1.3 0.8 1.0512 55 6 360.772 daN / m 3.608 kN / m

Gi ht:

'0

' C.B.K.q.nq

'q 1.3 0.6 1.0512 55 6 270.579daN / m 2.71kN / m

+19.100m

C1= -0.6

0.8

qd

-0.5

-0.6

-0.6

-0.6-0.8

0.7

qh-0.6

W

0.8

W

8700

4500

2197

1789

1580610

+16.900m

+19.700m

+15.400m

+13.200m

+8.700m

30000


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PHN IV:

XC NH NI LC KHUNG NGANG

thit lp s tnh cho khung ngang 1 cch n gin, ta gi thit:

Thay th ct bng cu kin thanh trng ci tim ct, c cng bng cng ct. Ct trn v ctdi c nn ng trc cng thm 1 moment lch tm ti vai ct. Thay th dn bng 1 thanhtrng vi cnh di dn.

Khi ti khng tc dng trc tip ln x, coi cng x bng v cng EJ = 00.

Gi s t l cng gia cc tit din trong thanh l :

cd

ct

j

j

= 8 ; d

ct

J

J

= 30 ( Chn s b)

1.TNH TI:

S tnh

Ton b tnh ti tc dng ln khung nh sau:q =B(qtt+gtt1+g

tt2/3)=6x(453+36+6)=2970 (daN/m)= 29.7 KN/m.

Lc dc trong ct trn khung bng:

q.L 2.97 30N 445.52 2 KN.

Moment lch tm t ti vai ct: M lt=N2x e =445.5x0.275=122.65 (KNm)

Ta c cc thng s sau tra bng:

4.50.34

4.5 8.7t

t d

Ha

h H Hv n= 2

1

10.125

8

J

J

Tra bng v ni suy ta c: KB= -0.6897 v KB= 1.4535.

Gii bi ton bng phng php chuyn v vi phng trnh chnh tc nh sau:

11 1. 0Pr R

Gii bi ton trn thnh 2 bi ton nh sau:

e=0.275

29.7 KN/m

4500

8700

30000


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Xt bi ton BT1:

a) Ni lc do chuyn v xoay 1 gy ra trn h c bn:- Moment v lc ct ti nh ct:

. . .0.6897B cd cdB

K E J E JM

h h v

'

2 2

. . .1.4535B cd cdB

K E J E JQ

h h

- M men v lc ct ti vai ct

.C B B t M M Q h =.

0.6897 cdE J

h-0.6897+ 2

.1.4535 cd

E J

hx4.5=0.585105 2

.cd

E J

h

- M men v lc ct chn ct

.A B BM M Q h =-0.6897+ 2.

1.4535 cdE J

hx13.2=0.7638

2

.cd

E J

h

A BQ Q - M men trong thanh x ngang:

4. . 3.75 15. . 6. .4d cd d d BC

E J Ex J E J E JM

L L L h

b) Moment do ti ngoi gy ra trong thanh x:2

2227.5( . )12

q

BC

qlM KN m ;

2

1113.75( . )24

q

Nhip

qlM KN m

Cc h s r11v R1Pc th xc nh nh sau:

r11= ( 0.6897) ( 6.6) 7.2897cd cd B BCEJ EJ

M Mh h

R1P= - BM =-2227.5 KNm

111

305.568P

cd

R h

r EJ

T ta tnh ra c gi tr ni lc cui cng:

29.7 KN/m

HCB 1 HCB 2122.65 KNm122.65 KNm

V

2227.5KNm2227.5 KNm

1113.75 KNm


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- Gi tr moment chn ct:0.7638 305.568.

233.393( )cdPA

cd

EJ hM x KNm

h EJ

- Gi tr moment nh ct:0.6897 305.568. 210.750( )cdPB

cd

EJ hM x KNmh EJ

- Gi tr moment u dn:6.6 305.568.

2227.5 210.751( )cdBC

cd

EJ hM x KNm

h EJ

- Gi tr moment gia dn:2 229.7 30

210.71 3130.499( )8 8nhip BC

ql xM M KNm

Biu mmen cui cng:

Xt bi ton BT2:

T cc thng s =0.34,x

h=

4.5

13.2=0.34 v n=0.125, tra bng ta c:

'

0.16118

1.4915B

B

k

k

- Momen v phn lc nh ct c xc nh nh sau:MB= KB.Mlchtm=-0.16118x(-122.65)=19.77 (KNm)

' 122.651.4915 13.8613.2

lechtamB B

MQ K xh (KN)

- Mmen ti chn ct trn:MII=MB+QB.Ht=19.77-(13.86x4.5)= -42.6 (KNm)

- Mmen ti nh ct di:MIII= -Mlechtam+MII=122.6- 42.366 =80(KNm)

- Momen ti chn ct:MA= MII+ QB.Hd= 80-(13.86x8.7)=-40.58 (KNm)

M0P

29.7 KN/m

29.7 KN/m

29.7 KN/m


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Cng kt qu 2 bi ton trn ta thu c biu moment gy ra do tnh ti:

Biu mment do tnh ti

Lc ct ti chn ct196.07 11.632

21.28.7

TT

AQ (KN)

2.HOT TI :

Tnh tng t trng hp tnh ti, vi qht= 5.88KN/m. Nh vy ch cn nhn cc tung biu

moment ca trng hp tnh ti vi t s5.88

0.19829.7

ht

tt

q

q

Biu moment nh sau:

40.58 KN/m

80 KN/m

19.77 KN/m

38.296 KN/m

M0P

190.98 KN/m

101.93 KN/m

192.81 KN/m

20.67 KN/m

38.209KN/m

19.531KN/m

38.82 KN/m

2.303 KN/m


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Lc ct ti chn ct 0.198 0.198 21.2 4.19( )HT TTA AQ Q x KN

3. P LC NG Dmax V Dmin:

Tng t nh trn bi ton cng c a v thnh 2 bi ton

- Bi ton 1: vi ct chu nn ng tm Dmax v Dmin (ch gy ra lc dc trong ct di chkhng gy ra moment).- Bi ton 2: vi cc moment Mmaxv Mmin( do Dmaxv Dmint lch tm ) gy ra ti vai ct.Cc moment lch tm:

Mmax=Dmaxx e=917.809x0.5=458.905 (KNm)

Mmin=Dminx e=217.597x0.5=108.799 (KNm)

a. Mment do ti trng ngoi gy ra trn h c bn:Tng t nh trng hp tnh ti:

-

Moment v phn lc nh ct c xc nh nh sau: MB= KB.Mlchtm=-0.16118x(458.905)= -73.966 (KNm)

' 458.9051.4915 51.8513.2

lechtamB B

MQ K x

h(KN)

- Mmen ti chn ct trn:MII=MB+QB.Ht=-73.966+51.85x4.5= 159.359 (KNm)

- Mmen ti nh ct di:MIII= -Mlechtam+MII=-458.905+159.359 = -299.546(KNm)

- Momen ti chn ct:MA= MII+ QB.Hd= -299.546+51.85x8.7= 151.549 (KNm)

Biu moment cho trng hp ny nh sau:

b. Ni lc do chuyn v thng n v gy ra trn h c bn:T ph lc ta tnh c cc h s KB=1.4535 v KB=-5.52095.

T :

2 2

. .. 1.4535cd cd BE J E J

M Kh h

'3 3

. .. 5.52095cd cd B B E J E JQ Kh h

4.067

0.429

17.536 KN/m1.453 1.453

4.067

0.429

73.966 KN/m

299.546 KN/m

159.359 KN/m

151.549 KN/m 35.893 KN/m

37.769 KN/m

71.03 KN/m

M Mp


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'2 2 2

. . .. ( ) 4.06745cd cd cd A A B BE J E J E J

M K K Kh h h

Xc nh h s r11v R1p:

Ct thanh dn v chiu tt c cc lc tc dng ln phng ngang ta xc nh c r11nh hnh v.Tng t ta cng xc nh c R1p:

R1P=-51.85+12.29=-39.56 (KN)

n chuyn v thng: 3 3111

39.563.58

11.0419P

cd cd

R h h

r EJ EJ

Vy moment trong h ban u:Ct tri:

- Moment ti nh ct: 0 1. 73.966 3.58 13.2 1.4535 5.28( )Bp PM M M x x KNm - Moment ti chn ct trn:

01. 159.359 3.58 ( 0.4286) 13.2 139.105( )

II

p PM M M x x KNm

- Moment ti nh ct di: 458.905 139.105 319.8( )III IIp lt PM M M KNm - Lc ct: 0 . 51.85 3.58 2.52095 32.085( )p BQ Q Q x KN - Moment ti chn ct: 0 . 151.549 4.06745 13.2 3.58 40.66( )Ap AM M M x x KNm

Ct phi:Tnh ton tng t nh trng hp trn ta c bng kt qu sau:

Q(KN) M (KNm)nh ct Chn ct trn nh ct di Chn ct

-7.475 -86.22 17.515 -91.287 228.10Cui cng ta c biu moment do Dmaxv Dmingy ra nh sau:

40.66 ( 319.8)0.198 17.19( )

8.7HT TT

A AQ Q KNm

r11=11.0419 EJcd/h3

R1p

5.52095EJcd/h3

5.52095 EJcd/h3 51.85 12.29

86.22 KN/m5.28 KN/m

319.8 KN/m

139.05 KN/m

40.66 KN/m 288.10 KN/m

17.515 KN/m

91.287 KN/m

Bi?u d? moment do Dmaxv Dmin


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T

MB= 0.1088 T.h

QB= 0.68597 T

4. LC X NGANG T :

S tnh:a) Ni lc do chuyn v n v gy ra trn h c bn:

Cc h s =0.34,x

h=

3.75

13.2=0.284 v n=0.125, tra bng ta c:

'

0.1088

0.68597B

B

k

k

b) Biu bao moment do ngoi lc gy ra trn h c bn 0PM :- Moment u ct:

MI=KBxTxh = -0.1088x63.685x13.2=-91.46 (KNm)

- Moment ti vtr t lc x ngang:Mx=MI+QBx X=-91.46+0.68597x63.685x3.75=72.36 (KNm)- Moment chn ct;

MIV=MI+ QB.h-T.(h-x)=-91.46+0.68597x63.685x13.2-63.685.(13.2-3.75)=-116.63 (KNm).

3.7

5

m

0.7

5m

13.2m

T= 63.685 KN


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Xc nh h s r11v R1p:

Ct thanh dn v chiu tt c cc lc tc dng ln phng ngang ta xc nh R1p:R1P= -43.69(KN)

n chuyn v thng: 3 3111

43.693.96

11.0419P

cd cd

R h h

r EJ EJ

Vy moment trong h ban u: 0 1.B

p PM M M

C th:Ct tri:

- Moment ti nh ct: 30 1 2. 91.46 3.96 1.4535 15.48( )cdB Pcd

EJhM M M x KNm

EJ h

- Moment ti v tr t lc x ngang:3

01 2. 72.36 3.96 ( 0.4286) 49.96( )

cdC P

cd

EJhM M M x KNm

EJ h

- Moment ti chn ct:3

01 2. 116.63 3.96 ( 4.06745) 329.24( )

cdA P

cd

EJhM M M x KNm

EJ h

Ct phi:

- Moment ti nh ct: 30 1 2. 0 3.96 1.4535 75.98( )cdB Pcd

EJhM M M x KNm

EJ h

- Moment ti v tr t lc x ngang:3

01 2

. 0 3.96 ( 0.4286) 22.40( )cdC Pcd

EJhM M M x KNm

EJ h

Moment ti chn ct:3

01 2. 0 3.96 ( 4.06745) 212.61( )

cdA P

cd

EJhM M M x KNm

EJ h

Biu moment nh sau:

116.63 KNm

24.74 KNm

91.46 KNm

4.067 4.067

0.429

1.453 1.453

4.067

0.429

M

R1p

43.69


19/80



+

-

-

5. TI GI :

Ni lc c tnh theo s nh sau:

a. Ni lc do chuyn v n v gy ra trn h c bn: Cc h s =0.34, v n=0.125, tra bng ta c:

'

0.05032

0.44322B

B

k

k

20.05032

0.44322B

B

M qh

Q qh

b. Biu moment do ngoi lc gy ra trn h c bn 0BM :Pha gi y:

- Moment u ct:2 2. . 0.05032 3.608 13.2 31.63( )dI B dM K q h x x KNm - Moment chn ct trn v nh ct di:

329.24 KNm

23.045 KNm

15.48 KNm

102.32 KNm

49.96 KNm 22.40 KNm

22.42 KNm

75.98 KN

qd

Wd

qh

So d? tnh

Wh


20/80



2 2. 3.608 4.5. 31.63 0.44322 3.608 13.2 4.5 26.83( )

2 2d d d t

II III I B t

q H xM M M Q H x x x KNm

- Moment chn ct:2 2. 3.608 13.2

. 31.63 0.44322 3.608 13.2 13.2 67.33( )2 2

d d

IV I B

q h xM M Q h x x x KNm

Tng t i vi pha ht gi (qh=2.71KN/m) ta c kt qu sau:

MA(KNm) MB(KNm) MC(KNm)

23.76 20.15 50.57

Biu mment gy ra trn h c bn

Xc nh h s r11v R1p:

trng hp trn ta xc nh c r11=11.0419 3cdEJ

h

Ct thanh dn v chiu tt c cc lc tc dng ln phng ngang ta xc nh R1p:R1p=21.11+15.85+10.65+16.12=63.73(KN)

n chuyn v thng:

3 31

11

63.73

5.7711.0419P

cd cd

R h h

r EJ EJ

Vy moment trong h ban u: 0 1.B

p PM M M

C th:Ct tri:

- Moment ti nhct:3

01 2

. 31.63 5.77 1.4535 79.07( )cdB Pcd

EJhM M M x KNm

EJ h

- Moment ti chn ct trn v nh ct:30

1 2. 26.83 5.77 ( 0.4286) 5.8( )cdC P

cd

EJhM M M x KNmEJ h

67.33 KNm

26.83 KNm

31.63 KNm

50.57 KNm

20.15 KN

23.76 KNm

Mp

R1p

21.11

10.65

15.85

16.12


21/80



- Moment ti chn ct:3

01 2

. 67.33 5.77 ( 4.06745) 377.12( )cdA Pcd

EJhM M M x KNm

EJ h

Ct phi:

- Moment ti nh ct: 30 1 2. 23.76 5.77 ( 1.4535) 86.94( )cdB Pcd

EJhM M M x KNmEJ h

- Moment ti chn ct trn v nh c di:3

01 2

. 20.15 5.77 ( 0.4286) 12.49( )cdC Pcd

EJhM M M x KNm

EJ h

Moment ti chn ct:3

01 2

. 50.57 5.77 ( 4.06745) 360.36( )cdA Pcd

EJhM M M x KNm

EJ h

Biu moment cui cng nh sau:

MTRMPH

377.12 KNm

5.8 KNm

79.07 KNm

360.36KNm

12.49 KNm

86.94 KNm

377.12 KNm

5.8 KNm

79.07 KNm

360.36KNm

12.49 KNm

86.94 KNm


22/80



PHN V:

T HP NI LC

1. BNG TM TT NI LC TRONG KHUNGTitdin

Hs

TH

Tnh ti(1)

Hot ti mi(2)

Dmaxtri(3)

Dmax phi(4)

T tri(5)

T phi(6)

G. Tri(7)

G.Phi(8)

M(KNm)

N(KN)

M(KNm)

N(KN)

M(KNm)

N(KN)

M(KNm)

N(KN)

M(KNm)

M(KNm)

M(KNm)

M(KNm

)I-I 1 -190.8 446 -38.21 88.2 -5.28 0 -86.22 0 15.48 75.98 79.07 -86.94

0.9 -190.8 446 -34.39 79.38 -4.752 0 -77.598 0 13.932 68.382 71.163 -78.246

II-II 1 -101.93 446 -19.53 88.2 139.23 0 17.52 0 20.05 22.42 -5.6 12.49

0.9 -101.93 446 -17.42 79.38 125.307 0 15.768 0 18.045 20.178 -5.04 11.241

III-III

1 20.67 446 2.30 88.2 -319.8 917.81 -91.29 217.6 20.05 22.42 -5.6 12.49

0.9 20.67 446 2.07 79.38 -287.82 826.029 -82.161 195.84 18.045 20.178 -5.04 11.241

IV-IV 1 192.81 446 38.82 88.2 -40.66 917.81 228.10 217.6 329.24 212.61 -377.12 360.36

0.9 192.81 446 34.938 79.38 -36.594 826.029 205.29 195.84 296.316 191.349 -339.408 324.304

2. BNG T HP NI LC TRONG KHUNGT hp I

Tit din Mmax-Nt Mmin-Nt NmaxMtM(KNm) N(KN) M(KNm) N(KN) N(KN) M+(KNm) M-(KNm)

I-I 1+8 1+2-277.92 446 534.2 -122.77

II-II 1+3 1+2 1+237.3 -129.46 534.2 534.2 -129.46

III-III 1+8 1+3 1+333.16 446 -299.13 1368.81 1363.81 -299.13

IV-IV 1+8 1+7 1+3553.17 446 -184.31 446 1363.81 152.15

T hp II

Titdin

Mmax-Nt Mmin-Nt NmaxMt

M(KNm) N(KN) M(KNm) N(KN) N(KN) M+(KNm) M-(KNm)I-I 1+2+4+6+8 1+2 +4+6+8

-449.596 525.38 525.38 -449.596II-II 1+3+6+8 1+2+7 1+2 +3+6+8 +7

54.796 446 -124.39 525.38 525.38 37.376 -124.39III-III 1+2+8 1+3+6+7 1+2+3 +6+7

33.981 525.38 -333.708 1272.029 1351.409 -290.298

IV-IV 1+2+4+5+8 1+3+5+7 1+2+3 +5+8 +5+71053.658 721.22 -479.508 1072.029 1351.409 811.774 -444.57


23/80



PHN VI:

THIT K CT

Ht =3.2m, ht= 0.45m

Hd=9.9m, hd= 1.0m

T s m men qun tnh ca tit din phn ct : 8J

J

t

d

Ni lc tnh ton : t bng t hp ni lc

+ Ct trn : cp ni lc nguy him nht :

M = - 449.596 kNm

N = 525.38 kN

+ Ct di :

M 479.508kNm; N 1072.029kN

M 1053.658kNm; N 721.22kN

T s lc nn ln nht ca phn ct di v phn ct trn :

d

t

t d

1

d t

2 t d

1

1 t d

N 1072.029

m 2.04N 525.38

H J 4.5 8C 1.024

H mJ 8.7 2.04 1

i J J 1 8K : : 0.242

i H H 4.5 8.7

Tra bng II.6a theo 2 thng s C1, K1v ni suy ta c1

2.014

12

1

2.0141.967

1.024C

Chiu di tnh ton trong mt phng khung :

1x 1 d

2x 2 t

l H 2.014 8.7 17.522m

l H 1.967 4.5 8.85m

Chiu di tnh ton ngoi mt phng khung :

1y d

2y t dct

l H 8.7ml H h 4.5 0.75 3.75m

1. THIT K CT TRN:


24/80



15

300

450

12

15

Chn tit din hnh ch H i xng t 3 bng thp

Ta c lch tm :

449.5960.86 86

525.38

Me m cm

N

S b chn tit din :

yct

N eF 1.25 2.2 2.8

R h

525.38 861.25 2.2 2.8 136.5 165.15 cm

21 1 45

= 1.25 : h s nh hng hnh dng tit din

R = 21kN/cm

2

: cng thit k ca vt liu thp.Chn :

b t

c c

c t

1 11.2cm h

30 50

1 11.5cm b

20 36

1 1b 30cm h

12 15

bh 45cm; h 42cm

ch

a 21.75cm2

Kim tra :

2c

2b

2c b

F 2 1.5 30 90cm

F 1.2 42 50.4cmF F F 140.4cm

3 32b b c c

x c c

3 32 4

h bJ 2 a b

12 12

1.2 42 30 1.52 21.75 1.5 30 50001cm

12 12


25/80



3 3c c b b

y

3 34

2 b hJ

12 12

2 1.5 30 42 1.26756cm

12 12

y

y

xx

3xx

t

J 6756r 6.94cm

F 140.4

J 50001r 18.87cm

F 140.4

2J 2 50001w 2222cm

h 45

2yy

y

2xx

x

l 375 54.03r 6.94

l 88546.90

r 18.87

Nh vy max 54.03 120

lch tm tng i m :

x

e F 86 140.4

m 5.4W 2222

Vi :

3

x x 6

R 2.1 1046.9 1.48

E 2.1 10

3

y y 6

R 2.1 1054.03 1.71

E 2.1 10

Ta c : cxb

F 901.25 5; 5 m 5.5 20; 1.79F 50.4

tra bng II.4 -ph lc II ta c :

1

1.4 0.02 1.4 0.02 1.48 1.37

m m 1.37 5.4 7.398

Ct khng cn kim tra bn v yc 1F F; m 20

* Kim tra n nh tng th trong mt phng un :

x 1.48 v m1= 7.398 tra bng II.2 -ph lc II ta c h s lt 0.180

2

lt

N 525.3820.78kN / cm

F 0.180 140.4(tha < 21 kN/cm2)


26/80



* Kim tra n nh tng th ngoi mt phng un :

Ta c M2= - 449.596 ng vi t hp 1,2,4,6,8 ti mt ct B ng vi u kia ta c m men tng

ng :

1M 101.93 17.42 15.768 20.178 11.241 112.519kNm

M men 1/3 on ct :

1 2'2

112.519 449.596449.596 337.237

3 3

M MM M kNm

Ta c : ' '2 1max , , 337.2372 2

M MM M kNm l gi tr m men a vo tnh ton.

lch tm tng i :

' 2

xx

M F 337.237 10 140.4m 4.06N W 525.38 2222

Vi mx= 4.06 < 5 tra bng II.5 -ph lc II ta c x0.65 0.005 m 0.67

Vi y CE

54.03 3.14 97R

tra bng II.5 -ph lc II ta c 1

H s nh hng ca m men trong mt phng un C c xc nh nh sau:

2

1C 0.269

1 m 1 0.67 4.06

y 54.03 ta tra bng II.1 -ph lc II y 0.849

Kim tra n nh tng th ca ct trn ngoi mt phng theo cng thc :

2 2y

y

N 525.3816.385kN / cm 21kN / cm

C F 0.269 0.849 140.4

* Kim tra n nh cc b :

- Bn cnh :

o C bC

C

b b 30 1.2: :1.5 9.62 2

Mc khc, theo bng 3.3 ta c i vi thp I c 48.0 x th

6o

3C

b E 2.1 100.36 0.1 0.36 0.1 1.25 15.34

R 2.1 10

Vy

C

o

C

o bb bn cnh tho mn iu kin n nh cc b.


27/80



- Bn bng :

V kh nng chu lc ca ct c xc nh theo iu kin n nh tng th trong mt phng khung nn

t s gii hnb

oh xc nh theo bng 3.4

Vi :

o

b

6

3

m 4.06 1 h E0.9 0.5

R1.48 0.8

2.1 100.9 0.5 1.48

2.1 1048.22

Tit din chn c :

o o

b b

h 45 2 1.5 h35 48.22

1.2

bn bng tho mn iu kin n nh cc b.

2. THIT K CT DI:Thit k ct di c:

2 cp ni lc nguy him. M1=1053.658 KNm ; N1=721.22 KN.

M2=-479.508 KNm ; N2=1072.029 KN.

0

479.508 1072.0291015.5

2 1 2tu

ct

NMN KN

h

0

1053.658 721.221414.268

2 1 2tu

mai

NMN KN

h

Cp M1cho Nnhnhln hn nn ta dng tnh ctNi lc tnh ton tit din I-I chn ct l:

Trng lng bn thn ct:

- Phn ct trn: G2=A.ht. =140.4x10-4x4.5x78.5=4.96KN.- Phnct di:

G1=2

37

721.22 10. . 7.85 10 1.4 8.7

. 0.5 2.1 10dN x

h x x x xK R x x

=660 daN=6.6KN

- Lc nn tng cng: N=1351.409+6.6+4.96=732.78 KN.a. S b chn tit din:Chiu cao tit din ct chn trc h=1.0m


28/80



lch tm1053.658

1.44732.78

Me m

N

Gi thit bn knh li rx=0.48xhd=0.48x100=48cm.

mnh 1 1752.2

36.548xx

x

l

r

3

6

2.1 1036.5 36.5 1.154

2.1 10xR x

xE x

lch tm tng i: 1144

1.25 3.9130.46 100

x

em x x

x

Tra bng ph lc II-7 vi 1.154x v m1=1.6 ni suy ta c lt 0.305

Din tch cn thit:

2732.78 144.(1.25 2.5 ) (1.25 2.8 ) 185. 21 100yc

N eA x cm

R h

Chn chiu dy bn bng1 1

( ) (12.5 4)80 250b d

h mm

Chn chiu dy bn bng b =1.0mm.

Din tch bn bng 21.0 100 100bA x cm

Din tch mi nhnh ct: 2185 100

432

cm

Chn nhnh cu chy: I-30 c cc c trng hnh hc:

F=46.5 cm2;Jx=7080 cm4; Jy=337 cm

4; Wx=472 cm3.

Nhnh mi:30x1.5=45 cm2.

- Din tch bn nhnh mi:230 1.5 45c c cF b x x cm

- Din tch bn bng:298.175 1 98.175b b bF h x x cm

- Din tch nhnh cu chy:

30

0

1000

13515

491.2

2.9

501.3

1

0

I-30


29/80



246.5cF cm

- Din tch ton ct:245 98.175 46.5 189.675F cm

- Khong cch t trc trng tm nhnh cu chy n trc tit din.( ) ( )

2 2 2

1.5 98.175 0.6545 (100 ) 98.175 ( )

2 2 2 49.12189.675

m bm d b

c

h dF x h F x

hF

x x

cm

- Khong cch t trc trng tm nhnh mi n trc tit din.hm= hd-hc-0.5x m =100-49.12-0.5x1.5=50.13 cm.

- Khong cch t trc trng tm bn bng n trc tit din.1.5 98.175

50.13 0.292 2 2 2

b dm

hy h cm.

- Cc moment qun tnh:3 3

2 2 2

3 32 2 2

4

( ) ( ) ( )12 12

30 1.5 1.0 98.175( 50.13 45) ( 0.29 98.175) (337 49.12 46.5)

12 12304487

d b b bx m m b xc c c

b x xhJ h xF y xF J h xF

x xx x x

cm

3 3 3

4

1.5 30 98.175 17080

12 12 12

10463

cy y

h x x xJ J

cm

Kim tra li gi thit: 1

2

30448729.1 8

10463

J

J=> m bo.

- Cc bn knh qun tnh:304487

40.07( )189.675

x

x

J

r cmF

104637.427( )

189.675y

y

Jr cm

F

- Gi tr mnh: 2 885 21.7440.07

xx

x

l

r

2 375 50.497.427

y

y

y

l

r

- mnh quy c: 36

2.1 1021.74 0.6872.1 10x x

R xx

E x


30/80



3

6

2.1 1050.49 1.597

2.1 10y yR x

xE x

- Cc moment khng un:3304487 5984.4141.5

50.1322

xxm

mm

JW cm

h

3304487 4410.93713.5

49.1222

xxc

cc

JW cm

bh

- Bn knh li tit din:5984.414

31.55189.675

xmx

Wcm

F

- lch tm tng i:144

4.56431.55

xx

x

em

- lch tm quy i:1 . 1.25 4.564 5.705xm m x

Tra bng ph lc II-7 vi 0.687x v m1=5.705 ni suy ta c lt 0.244

b.Kim tra cc b bn cnh:( nhnh mi)- n nh cc b ca bn cnh phi c m bo ngay t lc chn s b tit din: t s phn

vn ra v b dy ca n l:' 0.5( ) 0.5 (30 1)

9.661.5

d b

c m

bb xnh hn tr s quy nh bn 2 l

3

6

2.1 10(0.36 0.1 ) (0.36 0.1 0.687) 13.557

2.1 10

E xx

R x

Vy bn cnh nhnh mi n nh cc b.

c. Kim tra cc b bn bng.Vi bn bng ct, v kh nng chu lc ca ct c xc nh theo iu kin n nh tng th trong mt

phng khung nn t s gii hn o

b

hxc nh theo bng 3.4.

Khi m=4.564 v 0.687x 41.11 Bn bng b mt n nh cc b, ch c mt phn chiu

rng st hai cnh cng lm vic vi cnh. Chiu rng on cng lm vic:


31/80



6

1 3

2.1 100.85 0.85 1 27

2.1 10bE x

C x x x cmR x

T s thc t:6

3

2.1 1098.175 2.2 2.2 69.57

2.1 10

o

b

h E x

R x

.

Phi lm cc i sn ngang gia c bng bng.

Khong cch cc sng ngang a=2.5hb=2.5x98.175=245cm

B rng sn ngang: bs=981.75

40 72.730

mmchn bs=100mm.

Chiu dy sn:3

6

2.1 102 2 10 0.63

2.1 10s sR x

xb x x cmE x

. Chn s =8mm.

d.Kim tra n nh tng th trong mt phngkhung.Theo cng thc

.x lt

N

A

Vi lt tnh nh trn lt =0.244; A- din tch lm vic ca tit din.

A=Anhm+Anhct+2C1. b =45+46.5+2x27x1=145.5cm2.

Vy: 2732.78

20.64 .0.244 145.5x

KN

x cm < 21 2.KN

cmm bo n nh.

e. Kim tra n nh tng th ngoi mt phng khung.Cp ni lc tnh ton tit din I-I:

M1=1053.658 KNm ; N1=721.22 KN. ng vi t hp ti trng 1,2,4,5,8. Mment ng vi u kia,cng do cc ti trng 1,2,4,5,8 gy ra l:

Mc= -30.135 KNm;

Moment ln nht 1/3 chiu di ct l:

11053.658 ( 30.135 1053.658) 692.394

3M KNm.

0.5Mmax=0.5x1053.658=526.829 KNm


32/80



Theo ph lc 7 ta c:

50.49y < 99.296c th =1.

V khi 1


33/80



Mmax=54.796 KNm ; Ntu=446 KN.Mmin=-129.46 KNm ; Ntu=534.2 KN.

- Khong cch hai bn cnh ct trn: ' 45 1.5 43.5t t cb h cm - Ni lc ln nht m mi ni cnh ngoi ct trn phi chu:

max1'

446 54.796

2 2 0.435ngt

MNS

b349 KN.

- Ni lc ln nht m mi ni cnh trong ct trn phi chu:2 min'

534.2 129.46

2 2 0.435trt

N MS b 565 KN.

932.5 135 100

1167.5

50

50

50

30

200

450

750

500

20

20

120

15

76B?n K dy 15mm

D?m c?u ch?y80

57

36580

10

22

15

15 15

1000

300

450 650 167.5

200

300

400

1167.5

11

7

8


34/80



- Ni cnh ngoi bng ng hn i u thng, chiu di ng hn bng b rng cnh cttrn, chiu cao ng hn bng chiu dy thp cnh ct trn.

- ng sut trong ng hn i u cnh ngoi: 2349 81.5 (30 0.5 2)

ngh

h h

S KN

xl x x cm


35/80



- Chiu cao bn bng dm vai: phi cha 4 ng hn gc lin kt bn bng dm vai vibng nhnh cu trc.

+ gi thit chiu cao ng hn gc hh=10mm

+ Chiu di 1 ng hn cn thit l:

2 max( ) 932.809 282.51 24.114 (0.7 ) min 4 1 0.7 18

dcth

h g

D G Bl cm

xh x xR x x x

+ Chiu di 1 ng hn cn thit lin kt bn K vo bng dm vai ( 4 ng hn gc ny lin kt truyn lc Str).

2

min

5651 11.2

4 (0.7 ) 4 1 (0.7 18)

trh

h g

Sl cm

xh x xR x x x

+ iu kin hdv 0.5xhd=0.5x100=50cm. Chn hdv=50cm.

+ Chn chiu dy bn di dm vai cv =10mm.

+ Chiu cao bn bng dm vai hbdv=hdv-( bd cv )=50-(2+1)=47cm.

- Kim tra iu kin chu un ca dm vai:Tit din ch I ca dm vai khng i xng gm cnh di dm vai thng l mt bn thp nmngang ni bn bng ca hai nhnh ct di.

Cnh trn ca dm vai thng l hai bn thp ( bn y mt nhnh cu trc v bn sn lt).

c th tnh ton n gin v thin v an ton ta quan nim ch c bn bng dm vai chu un.

- Moment khng un ca bn bng:2 2

32 47 736.336 6

dv bdvxh xW cm

- Kim tra iu kin chu un ca dm vai(tit din ch nht):2

max2

141.25 1019.18

736.33

dvM x KN

W cm B= 30+2(1+4)=40cm.


36/80



Chiu dibn tnh c theo gi thit ng sut ln nht ti mp bn t c cng p cc b ca btng mng theo cng thc:

2

.

6( )

2. . 2. . .m m

N N ML

B R b R B R

- Chn cp ni lc tnh tonM=1053.658 Km

N=721.22 KN

- Rn=150 2kGcm : cng chu nn ca vt liu lm mng BTCT mc 250- Rm= 33 1.50 1.2nR x =1.594 2KNcm ( = mbd

F

Fgi thit =1.2).

22721.22 721.22 6 1053.658 10( )

2 40 1.594 2 40 1.594 40 1.594

x xL

x x x x x=105.39cm

- tin li cho cu to chn ct ta chn L=150 cm.b. Tnh chiu dy bn :

- ng sut bn di bn :2

max 2 2 2

2

min 2 2 2

6 721.22 6 1053.658 100.823

. . 40 150 40 150

6 721.22 6 1053.658 100.582

. . 40 150 40 150

N M x x KN

B L B L x x cm

N M x x KN

B L B L x x cm

B dy ca bn c xc nh t iu kin chu un do phn lc mng khi tnh moment un. Titrng tng bn c xem nh phn b u v bng ng sut ln nht trong .

- Tnh ng sut nn ln nht ca btng mng di sn chn ct l: 1 max

2

0.823KN

cm

12 max min min 2

150 14( ) (0.823 0.582) 0.582 0.692

150

L a KN

L cm

1 23 max min min 2

( ) 150 (10 14)( ) (0.823 0.582) 0.582 0.5982

150

L a a KN

L cm

1 2 34 max min min 2

( ) 150 (10 14 31)( ) (0.823 0.582) 0.582 0.308

150

L a a a KN

L cm

5 max min min 2

1 1( ) (0.823 0.582) 0.582 0.121

2 2

KN

cm.

- 1: Bn lm vic nh cng sn:


37/80



2 21 1

11

24 0.823 54.8 2 10.288

5 2 2cb xa xM KNcm

a.

- 2: Bn lm vic nh bn k 4 cnh: 2 2

2 2 2 22

30 2.143 . 0.125 0.729 14 17.86114

cb M xa x x KNcma

.

- 3: Bn lm vic nh bn k 3 cnh: 2 2

3 3 3 33 3

400.645 . 0.081 0.5982 31 46.564

2 2 31cb B M xa x x KNcm

a a x.

- 4: Bn lm vic nh bn k 3 cnh:2 2

4 4 4 44

401 . 0.112 0.308 20 13.798

2 20cb M xa x x KNcm

a x.

Mment dng tnh chiu dy bn l:

M= max(M1, M2, M3, M4)=46.564 KNcm.

- Chiu dy bn :6 6 46.564

3.647 421bd

M xcm cm

RChn bd =4cm=40mm.

c. Tnh dm :-

Chiu di ng hn lin kt chn ct vi dm cng chnh l chiu cao dm .- Chiu di dm : ld=24cm- Dm lm vic nh conson chu p lc phn b di bn :

300X1

0

300x15 1

0

10

O 3 O 3

O 3 O 3

O 3 O 2

O 4

O 4

O 4

O 4

O 3O 2

O 1


38/80



max

400.823 16.46

2 2dB KN

q x xcm

- Momen: Md = 2 22416.46 4740.482 2

dd

lq x x KNcm

- Lc ct: Q d =q d x l d =16.46x24=395.04 KN.- Ly b dy dm

d=1cm

- Chiu cao cn thit cho tit din cu un:6 6 4740.48

36.802. 1 21d

d

d

M xh cm

R x

- Chiucao cn thit cho tit din chu ct:395.04

30.3881 13d

d

Qh cm

xR x

- Dng tit din bn dm 40x1cm chung cho c 2 nhnh- 3 2 31 1. . 1 35 266.667

6 6d d d W h x x cm

Kim tra dm :

2

4740.4817.777

266.667d

d

M KN

W cm t yu cu.

Kim tra tit din dm theo iu kin chu ct:

2

395.049.876

. 1 40d

d d

Q KN

h x cm t yu cu.

Tnh ng hn lin kt dm vo nhnh ct: Hn dm vo nhnh ct bng hai ng hn ng c chiu di ng hn l:

- Lh=h d =40cm- ng hn lin kt dm vo nhnh c hh=10mm

2 230.7 ( 1) 0.7 1 (40 1) 177.45

6 6h d

h

xh x h x xW cm

- Din tch ng hn:20.7 ( 1) 0.7 1 (40 1) 27.3h h dF xh x h x x cm

Kim tra ng hn:


39/80



2 2

4740.4813.357 21

2. 2 177.45d

h

M KN KN R

W x cm cm=> t yu cu.

2 2

395.047.235 15

2. 2 27.3hd

g

h

Q KN KN R

F x cm cm=> t yu cu.

2 2 2 22 2

13.357 7.235 15.19 15ht h h g KN KN

Rcm cm

chnh lch cho php: 15.19 15

100% 1.25% 5%15.19

x c th chp nhn c.

ng hn kh nng chu lc.

d. Tnh sn ngn:+ Sn ngn A:

S tnh l dm n gin c lA=bc=30cm.

- Ti trng:2

2 1

14( ) 0.729 (10 ) 12.393

2 2Aa KN

q a xcm

- Moment:2 212.393 30

1394.2138 8

AA

q xl xM KNcm

- Lc ct ti tit din u dn( hn vi dm )

200

X10

200

X10

200

X1

0

200

X1

0

200X10

300X1

0

300x15 1

0

15

350X10

250X10

250X10

250X10


40/80



12.393 30185.895

2 2A

A

q xl xQ KN

- Dng sn ngang cao bng chiu cao dm : hA=40cm.- B dy sn ngn 1.0

sn

cm

2 2 2 2

6 6 1394.2136.829 21

1 35A

A

A A

M x KN KNR

xh x cm cm

- B dy ng hn lin kt sn ngn A vo dm ( lin kt 2 bn):0.5 12.393 0.5 30

0.32 0.7 2 0.7 (30 1) 15

A Ah h

h g

q x l x xh cm

x xl xR x x x.

Dng hh=8mm.

+ Sn gia c B:

S tnh l dm conson c lB=0.5x40=20cm.

- Ti trng:3 4

4

31 400.308 10.934

2 4 2 2Ba a KN

q xcm

.

- Moment:2 210.934 20

2186.82 2

B BB

q xl xM KNcm

- Lc ct:10.934 20 218.68

B B BQ q xl x KN .

- Chiu cao cn thit ca sn ngn B tnh theo iu kin chu un6 6 2186.8

24.9. 1 21

BB

B

M xh cm

R x.

Chn hB= 25cm.

- B dy sn ngn B l 10sn mm 2 2

6 6 2186.8 3.499 211 25 2 2

BB

B B

M x KN KN Rxh x cm cm

- B dy ng hn lin kt sn ngn B vo dm ( lin kt 2 bn): 10.934 20

0.542 0.7 2 0.7 (20 1) 15

A Bh h

h g

q xl xh cm

x xl xR x x x. Dng hh=8mm.

+ Sn gia c B1:

S tnh l dm conson c lB1=20cm.

- Ti trng:4 2

1 5

31 310.121 3.751

2 2 2 2Ba a KN

qcm


41/80



- Moment:2 2

1 11

3.751 20750.2

2 2B B

B

q xl xM KNcm

-

Lc ct:.

B b BQ q l 3.751x20=75.02KN.

- Chiu cao cn thit ca sn ngn B tnh theo iu kin chu un:1

11

6 6 750.214.64

1 21B

B

B

M xh cm

xR x

Chn hB1=25cm.

- B dy sn ngn B l 10sn mm .12 2 2

1 16 6 750.2 7.2021 25

BB

B B

M x KNxh x cm

- B dy ng hn lin kt sn ngn B1vo dm (lin kt 2 bn):1 3.751 20 0.19

2 0.7 2 0.7 (20 1) 15B B

h h

h g

q xl xh cm

x xl xR x x x=>Dng hh=8mm.

+ Tnh cc ng hn ngang lin kt vo bn theo phn lc t bn trn 1 gii 1cm:

- ng hn lin kt dm vo bn :16.46

0.7842. . . 2 0.7 15 1

d

h hg h

q

h cml x x x => Chn hh=0.8cm

- Sn A lin kt vo bn (1 ng hn).12.393

0.592. . . 2 0.7 15 1

Ah h

g h

qh cm

l x x x=> Chn hh=0.8cm

- Sn B lin kt vo bn (2 ng hn).10.934

0.5212. . . 2 0.7 15 1

Bh h

g h

qh cm


- Sn B1 lin kt vo bn (2 ng hn).1 3.751 0.179

2. . . 2 0.7 15 1

Bh h

g h

qh cm


Vy ta dng mi ng hn ngang lin kt vi bn u dy 8mm.

e. Tnh bu long neo:T bng t hp ni lc ct, tit din chn ct (IV-IV), tm ra cp ni lc cho moment un ln nht vlc dc nh nht. Trong trng hp ny ta tm c cp ni lc (5,7) do lc hm ca cu trc v gi

tri gy nn l:


42/80



M=329.24

0.9 377.12 646.4981.1

x KNm .

N=212.61

0.9 173.9541.1

x KN.

+ bu long neo nhnh mi:

- ng sut ti y mng:maxmin

2

2 2

173.954 6 646.498 100.029 0.431

40 150 40 150

N M x x KN

F W x x cm.

=>max 2

min 2

0.46

0.402

KN

cm

KN

cm

Ta c:

Y1= max

max min

0.46150 80.046 .

0.46 0.402xL x cm

Y2=L- Y1=150-80.046=69.954cm.

- Khong cch t trng tm vng nn n mp bn l:1

1 180.046 26.682 .

3 3X Y x cm

- Khong cch t im t lc n trng tm vng b tong nn l:Y=L-a1-x= 150-10-26.682=113.318cm.

- Din tch bu long chu ko cn thit l:2646.498 10 173.954 (0.5 150 26.682)

113.318 14th neo

M Nxa x x xF

YxR x35.453 cm2.

Dng 2 bulong ng knh 56mm c din tch chn Fchn=19.02x2=38.04 cm2.

+ Tnh bu long neo nhnh cu chy:

Dung 2 bulong neo nhnh cu chy ng knh 56mm c din tch chn Fchn=19.02x2=38.04 cm2.

- Lc ko ln nht trong 1 bulng l:Nk=

2646.498 10 173.954 (0.5 150 26.682)248.172

2. 2 113.318

M N a x x

YKN.

- Tnh chiu di neo bulng vo btng mng Cng lc dnh gia btng v bulng l:

=402

KN

cm.

- Chiu di neo bulng:


43/80



K

bl neoneo

F Rl

n

- Trong :1. Rn=1.5

2

KN

cm

2. m= (3.6-6) chn m=43. =

2

1.50.375

4nR KN

m cm

4. n=4(3.14x5.6)=70.336cm.5. lneo= 38.04 14 20.191 .

0.375 70.336 cm

vy chn lneo=25cm.

+ tnh sn conson bulng neo qua qu m bng thp gc L:

- chn dm k bulng l thp hnh L 200x125x11.- Khong cch t trc bulng n dm l e= 15cm.- Sn bulng neo tnh nh conson nhp e=15cm.- Hn cc sn vo dm .- Moment ti tit din ngm( hn sn vo dm ).

M =NKx e= 248.172x15=3722.58 KNm.- Chn sn dy 10mm, cao 30cm.- Kim tra tit din sn.

2 2 2

6 3722.5810.489 21

2. 2 0.7 1 (40 1)s

M KN KN

W cm cm=> t.

2

248.1724.545

2 2 0.7 1 (40 1)K

s

N KN

F cm t.

2 2 2 2

10.489 4.545td h h =11.431 2KN

cm < h

gR =15 2

KN

cm .

Vy ng hn kh nng chu lc.


44/80



PHN VII:

THIT K DN MI

A. TNH NI LC THEO PHNG PHP GIN CRMNA:1. S V KCH THC CHNH CA DN:

Dn c s hnh thang, dc cnh trn i = 0.1 0 chiu cao u dn l 2.2m

Chiu di thc t ca dn :L0= L2ht= 302 x 0.45 = 29.1 m

Kt cu ca tri :Lct= 12 m, cao 2.2 m

Ta c s dn :

2. TI TRNG TC DNG LN DN:

a. Tnh ti :

Trng lng mi: gkc= 0.36 2KN

m

Trng lng ca tri: gct= 0.18 2KNm

Trng lng cc lp vt liu mi: gm=4.35 2KN

m.

Trng lng cnh v bu ca mi: Gct=6KN.

Moment u dn do tnh ti mi gy ra: Mtr=Mph=-190.98 KNm.

b. Hot ti : hot ti mi

Hot ti y l hot ti sa cha mi phn b u theo phn nm ngang v c gi tr:

p=5.88KN/m2.Mment u dn: Mtr=Mph=-38.209 KNm.

c. p lc ng maxtrD :

Mment u dn : Mtr=5.28 KNm.

Mph=86.22 KNm.

Trng hp maxphD s ly kt qu i xng trong trng hp max

trD qua trc gia dn.

d. Lc hm ngang Ttr:

M men u dn :15.48

75.98tr

ph

M kNm

M kNm


45/80



3. TNH TON NI LC TRONG DN:

* Ni lc tnh ton ca cc thanh dn : xc nh bng phng php gii crmona :

Tnh chi tit :

a. Ti trng thng xuyn-Nt u dn :

1 m d

dB 3 6G g g 4.53 0.36 44.01kN

2 2

- Nt trung gian:

G2= 2G1= 44.01 x 2 = 88.02 kN

-Nt ti chn ca tri :

2

3 2 ct ct

3

d B

G 2G g G23 6

G 88.02 0.18 95.64kN2

-Nt c kt cu ca tri :

4 ct 2G d.B.g G 3 6 0.18 88.02 91.26kN

S tnh

Gin Crmna trng hp tnh ti

Kt qu ni lc trong dn nh sau:

12

3 4

5

6 7

8

9 10

11

1213

14

15

a

c

b

d ef g

h k l m

n o p44.01 88.02

88.02 95.64

91.2691.26

86.8

86.8

452.58 452.58

872

7165

7165

9177

9177

913

588

880

224

4634

3893

6518

8690

8761

4526

4139

353bd c

1e

2 a

f

3

4

g

5

6

h

k

7

8


46/80



Thanh a-2 a-5 a-8 c-1 e-1 f-3 g-4 h-6

N(KN) 413.9 869.0 876.1 -35.3 87.2 -716.5 -716.5 -917.7

Thanh k-7 1-2 2-3 3-4 4-5 5-6 6-7 7-8

N(KN) -917.7 -651.8 389.3 -88.0 -224.4 63.4 -91.3 58.8

b. hot ti sa cha mi :

- Vi nt u dn :

P1= 0.5 x d.P = 0.5 x 3 x 5.88 = 8.82 kN

- Vi nt trung gian :

P2= 2P1= 2 x 8.82 = 17.64 kN

- Vi nt ti chn ca triP3= P2/2 + 0.5 d2P = 8.82 + 0.5 x 3 x 5.88 = 17.64kN

- Vi nt c kt cu ca tri :

P4= d2.P = 3 x 5.88 = 17.64 kN.

Moment u dn c thay th bng mt cp ngu lc c gi tr38.209

2.2=17.368 KN.

Vi cc dn phn nh : tch dn phn nh, xc nh ti trng t mt v dn phn nh. v gin dn. an ton ta xem nh lc t mt dn phn nh l hot ti c tr s bng (P2+ G2). Ni lctrong thanh dn phn nh c cng vo ni lc ca thanh chnh khi ni lc ca thanh dn phn nhlm tng ni lc tnh ton ca thanh chnh .

S tnh

Gin Crmna trng hp hot ti

12

3 4

5

6 7

8

9 10

11

1213

14

a

c

b

d ef

gh

k l mn o

p8.8217.64

17.64 17.64

17.6417.64

17.368

17.368

88.2 88.2

15

12671

13824

13824

17641

17641

1764

422

3

1239

1764

1116

7997

16692

16846

17630

17641

7495

708

1745

a

e

f

g

h

k

1

2

3

4

5

6

78


47/80



Kt qu ni lc trong dn nh sau:

Thanh a-2 a-5 a-8 c-1 e-1 f-3 g-4 h-6

N(KN) 79.97 166.92 168.46 -7.08 17.45 -138.24 -138.24 -176.41

Thanh k-7 1-2 2-3 3-4 4-5 5-6 6-7 7-8

N(KN) -176.41 -126.71 74.95 -17.64 -42.23 12.39 -17.64 11.16

c. p lc ng Dmaxtr:Mtr=-5.28 KNm; Mtr=-86.22KNm

Ti khng tc dng trc tip ln dn do chng ta s gii cho trng hp M tr=1 (trng hp Mph=1s ly i xng qua trc dn).

S tnh

Gin Crmna trng hp M=+1 t ti u dn tri

Ni lc trong dn s c xc nh nh sau:

ij ijtr tr ijph phN N M N M

12

3 4

5

6 7

8

9 10

11

1213

14

a

c

b

d

0.4545

0.4545

0.0333 0.0333

15

4082 519

5

cb

a

d

1

e

2

3, 4

5

6, 7

8

9, 10

11

12, 13

14

15

3330

4032

9697

13524

22587

36000

4545

1230

1966

5

8611

17744

28717

7091

656

0

2771

41

2995

11838

45677

3637


48/80


49/80



d. Lc hm ngang T :Mtr=-15.48 KNm; Mtr=-75.98KNm

Ni lc trong dn do lc hm

Thanh Mment n v max

trT max

phT

Mtr=1 M h=1 Mtr=-15.48 M h=-75.98 Lc dc M h=-15.48 Mtr=-75.98 Lc dc(1) (2) (3) (4) (5) (6) (7) (8) (9)

a2 0.36 0.04 -5.5728 -3.0392 -8.612 -0.6192 -27.3528 -27.972

a5 0.226 0.097 -3.49848 -7.37006 -10.86854 -1.50156 -17.17148 -18.67304

a8 0.135 0.135 -2.0898 -10.2573 -12.3471 -2.0898 -10.2573 -12.3471

a11 0.097 0.226 -1.50156 -17.17148 -18.67304 -3.49848 -7.37006 -10.86854

a14 0.04 0.36 -0.6192 -27.3528 -27.972 -5.5728 -3.0392 -8.612

d1 -0.457 0 7.07436 0 7.07436 0 34.72286 34.72286

d3=d4 -0.287 -0.072 4.44276 5.47056 9.91332 1.11456 21.80626 22.92082

d6=d7 -0.177 -0.118 2.73996 8.96564 11.7056 1.82664 13.44846 15.2751

d9=d10 -0.118 -0.177 1.82664 13.44846 15.2751 2.73996 8.96564 11.7056

d12=d13 -0.072 -0.287 1.11456 21.80626 22.92082 4.44276 5.47056 9.91332

d15 0 -0.457 0 34.72286 34.72286 7.07436 0 7.07436

c1 -0.045 0 0.6966 0 0.6966 0 3.4191 3.4191

0 0 0 0 0 0 0 01_2 0.123 -0.052 -1.90404 3.95096 2.04692 0.80496 -9.34554 -8.54058

2_3 -0.097 0.041 1.50156 -3.11518 -1.61362 -0.63468 7.37006 6.73538

3_4 0 0 0 0 0 0 0 0

4_5 0.0861 -0.036 -1.332828 2.73528 1.402452 0.55728 -6.541878 -5.984598

5_6 -0.071 0.03 1.09908 -2.2794 -1.18032 -0.4644 5.39458 4.93018

6_7 0 0 0 0 0 0 0 0

7_8 0.066 -0.028 -1.02168 2.12744 1.10576 0.43344 -5.01468 -4.58124

8_9 -0.028 0.066 0.43344 -5.01468 -4.58124 -1.02168 2.12744 1.105769_10 0 0 0 0 0 0 0 0

10_11 0.03 -0.071 -0.4644 5.39458 4.93018 1.09908 -2.2794 -1.18032

11_12 -0.036 0.0861 0.55728 -6.541878 -5.984598 -1.332828 2.73528 1.402452

12 _13 0 0 0 0 0 0 0 0

13_14 0.041 -0.097 -0.63468 7.37006 6.73538 1.50156 -3.11518 -1.61362

14_15 -0.052 0.123 0.80496 -9.34554 -8.54058 -1.90404 3.95096 2.04692


50/80



e. p lc gi :Mtr=79.07 KNm; Mtr=-86.94KNm

Thanh

Mment n v GI TRI GI PHI

Mtr=1 Mph=1 Mtr=79.07 Mph=-86.94 Lc dc Mph=79.07 Mtr=-86.94 Lc dc

(1) (2) (3) (4) (5) (6) (7) (8) (9)a2 0.36 0.04 28.4652 -3.4776 24.9876 3.1628 -31.2984 -28.1356a5 0.226 0.097 17.86982 -8.43318 9.43664 7.66979 -19.64844 -11.9787a8 0.135 0.135 10.67445 -11.7369 -1.06245 10.67445 -11.7369 -1.06245a11 0.097 0.226 7.66979 -19.64844 -11.9787 17.86982 -8.43318 9.43664a14 0.04 0.36 3.1628 -31.2984 -28.1356 28.4652 -3.4776 24.9876d1 -0.457 0 -36.13499 0 -36.135 0 39.73158 39.73158d3=d4 -0.287 -0.072 -22.69309 6.25968 -16.4334 -5.69304 24.95178 19.25874

d6=d7 -0.177 -0.118 -13.99539 10.25892 -3.73647 -9.33026 15.38838 6.05812d9=d10 -0.118 -0.177 -9.33026 15.38838 6.05812 -13.99539 10.25892 -3.73647d12=d13 -0.072 -0.287 -5.69304 24.95178 19.25874 -22.69309 6.25968 -16.4334d15 0 -0.457 0 39.73158 39.73158 -36.13499 0 -36.135c1 -0.045 0 -3.55815 0 -3.55815 0 3.9123 3.9123

0 0 0 0 0 0 0 01_2 0.123 -0.052 9.72561 4.52088 14.24649 -4.11164 -10.69362 -14.80532_3 -0.097 0.041 -7.66979 -3.56454 -11.2343 3.24187 8.43318 11.675053_4 0 0 0 0 0 0 0 04_5 0.0861 -0.036 6.807927 3.12984 9.937767 -2.84652 -7.485534 -10.33215_6 -0.071 0.03 -5.61397 -2.6082 -8.22217 2.3721 6.17274 8.544846_7 0 0 0 0 0 0 0 07_8 0.066 -0.028 5.21862 2.43432 7.65294 -2.21396 -5.73804 -7.9528_9 -0.028 0.066 -2.21396 -5.73804 -7.952 5.21862 2.43432 7.652949_10 0 0 0 0 0 0 0 010_11 0.03 -0.071 2.3721 6.17274 8.54484 -5.61397 -2.6082 -8.2221711_12 -0.036 0.0861 -2.84652 -7.485534 -10.3321 6.807927 3.12984 9.93776712 _13 0 0 0 0 0 0 0 013_14 0.041 -0.097 3.24187 8.43318 11.67505 -7.66979 -3.56454 -11.234314_15 -0.052 0.123 -4.11164 -10.69362 -14.8053 9.72561 4.52088 14.24649


51/80



f. Ni lc trong dn :

ThanhTnhti Hot Ti max

trD maxphD trT trT phT phT Gi tri Gi phi

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11)

a2 413.9 79.97 -5.3496 -31.2504 -8.612 8.612 -27.972 27.972024.9876 -28.1356

a5 869 166.92 -9.55662 -19.9979 -10.8685 10.869 -18.673 18.67309.43664 -11.9787

a8 876.1 168.46 -12.3525 -12.3525 -12.3471 12.347 -12.3471 12.3471-1.06245 -1.06245

a11 869 166.92 -19.9979 -9.55662 -18.673 18.673 -10.8685 10.8685 -11.9787 9.43664

a14 413.9 79.97 -31.2504 -5.3496 -27.972 27.972 -8.612 8.6120 -28.1356 24.9876

d1 87.2 17.45 2.41296 39.40254 7.07436 -7.074 34.72286 -34.7229 -36.135 39.73158

d3=d4 -716.5 -138.24 7.7232 25.1253 9.91332 -9.913 22.92082 -22.9208-16.4334 19.25874

d6=d7 -917.7 -176.41 11.10852 15.88398 11.7056 -11.706 15.2751 -15.2751-3.73647 6.05812

d9=d10 -917.7 -176.41 15.88398 11.10852 15.2751 -15.275 11.7056 -11.70566.05812 -3.73647

d12=d13 -716.5 -138.24 25.1253 7.7232 22.92082 -22.921 9.91332 -9.9133 19.25874 -16.4334

d15 87.2 17.45 39.40254 2.41296 34.72286 -34.723 7.07436 -7.0744 39.73158 -36.135

c1 -35.3 -7.08 0.2376 3.8799 0.6966 -0.697 3.4191 -3.4191-3.55815 3.9123

1_2 -651.8 -126.71 3.834 -10.3305 2.04692 -2.047 -8.54058 8.540614.24649 -14.8053

2_3 389.3 74.95 -3.02286 8.14686 -1.61362 1.614 6.73538 -6.7354-11.2343 11.67505

3_4 -88 -17.64 0 0 0 0.000 0 0.0000 0 0

4_5 -224.4 -42.23 2.649312 -7.23346 1.402452 -1.402 -5.9846 5.9846 9.937767 -10.3321

5_6 63.4 12.39 -2.21172 5.96322 -1.18032 1.180 4.93018 -4.9302-8.22217 8.54484

6_7 -91.3 -17.64 0 0 0 0.000 0 0.0000 0 0

7_8 58.8 11.16 2.06568 -5.54268 1.10576 -1.106 -4.58124 4.58127.65294 -7.952

8_9 58.8 11.16 -5.54268 2.06568 -4.58124 4.581 1.10576 -1.1058-7.952 7.65294

9_10 -91.3 -17.64 0 0 0 0.0000 0 0.0000 0 0

10_11 63.4 12.39 5.96322 -2.21172 4.93018 -4.930 -1.18032 1.1803 8.54484 -8.22217

11_12 -224.4 -42.23 -7.23346 2.649312 -5.9846 5.985 1.402452 -1.4025-10.3321 9.937767

12 _13 -88 -17.64 0 0 0 0.000 0 0.00000 0

13_14 389.3 74.95 8.14686 -3.02286 6.73538 -6.735 -1.61362 1.613611.67505 -11.2343

14_15 -651.8 -126.71 -10.3305 3.834 -8.54058 8.541 2.04692 -2.0469-14.8053 14.24649


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f. T hp ni lc :

ThanhT hp c bn 1 T hp c bn 2 Ni lc tnh ton

Nmax Nmin Nmax Nmin Nmax Nmin

1 2 3 4 5 6 7

a2 493.87 382.65 508.362 335.278 508.36 335.278

a5 1035.92 849.00 1027.721 823.415 1035.92 823.415

a8 1044.56 863.75 1027.714 852.914 1044.56 852.914

a11 1035.92 849.00 1027.721 823.415 1035.92 823.415

a14 493.87 382.65 508.362 335.278 508.36 335.278

d1 126.93 51.07 205.376 54.679 205.38 51.065

d3=d4 -691.37 -854.74 -655.926 -855.706 -655.93 -855.706

d6=d7 -901.82 -1094.11 -884.205 -1079.832 -884.20 -1094.110

d9=d10 -901.82 -1094.11 -884.205 -1079.832 -884.20 -1094.110

d12=d13 -691.37 -854.74 -655.926 -855.706 -655.93 -855.706

d15 126.93 51.07 205.376 54.679 205.38 51.065

c1 -31.39 -42.38 -25.210 -44.874 -25.21 -44.874

0.00 0.00 0.000 0.000 0.00 0.000

1_2 -637.55 -778.51 -633.685 -796.148 -633.69 -796.148

2_3 464.25 378.07 480.657 375.016 480.66 375.016

3_4 -88.00 -105.64 -88.000 -103.876 -88.00 -105.640

4_5 -214.46 -266.63 -211.809 -283.602 -211.81 -283.602

5_6 75.79 55.18 92.045 52.947 92.05 52.947

6_7 -91.30 -108.94 -91.300 -107.176 -91.30 -108.940

7_8 69.96 50.85 78.586 42.532 78.59 42.532

8_9 69.96 50.85 78.586 42.532 78.59 42.532

9_10 -91.30 -108.94 -91.300 -107.176 -91.30 -108.940

10_11 75.79 55.18 92.045 52.947 92.05 52.947

11_12 -214.46 -266.63 -211.809 -283.602 -211.81 -283.602

12 _13 -88.00 -105.64 -88.000 -103.876 -88.00 -105.640

13_14 464.25 378.07 480.657 60.666 480.66 60.666

14_15 -637.55 -778.51 -633.685 -796.148 -633.69 -796.148


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B. TNH NI LC THEO PHN MM SAP 2000:

TABLE: Element Forces - Frames

Frame Station OutputCase CaseType StepType StepNum P

Text m Text Text Text Unitless KN

12 0 DEAD LinStatic 497.548





22 1.50748 DEAD LinStatic 2.08E-13

23 0 DEAD LinStatic -797.267














47 0 DEAD LinStatic 67.17348 0 DEAD LinStatic 67.612










4547

49 56 5243

12

44 53

14

46 57

16

48 55

18

5051

20

5842

2223

2425

26 2728

29 3031


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C. NHN XT-CHN PHNG N TNH TON CC THANH DN:

Da vo kt qu ni lc ca 2 phng php tnh ton cho dn ta nhn thy kt qu gn ging nhau.Nguyn nhn dn n kt qu c sai s l do ta quy c cc h s trong qu trnh tnh ton.

T 2 kt qu tnh c th ta ly kt qu gii th cng i tnh ton thanh dan v kt qu ny c gi trni lc ln hn gy nguy him hn.

D. TNH TON CC THANH DN:

1. XC NH CHIU DI TNH TON CC THANH DN:

Mi lp panen btng loiln kch thc 6x1.5m nn ta b tr h thng dn phn nh nh trn.

Cc thanh dn c phn thnh 3 loi nh sau:

Loi thanh Tn Thanh Nmax Nmin l(m)lox(m) loy(m)

Thanh xin u dn 1_2 -633.69 -796.1477 3.9 1.95 3.9

Thanh bng

c_1 -25.21 -44.87434 2.2 0.88 2.2

2_3 480.66 375.01627 3.9 1.56 3.9

3_4 -88.00 -105.64 2.8 1.12 2.8

4_5 -211.81 -283.6021 4.31 1.724 4.31

5_6 92.05 52.947211 4.31 1.724 4.31

6_7 -91.30 -108.94 3.4 1.36 3.47_8 78.59 42.531672 4.76 1.904 4.76

Thanh Cnh Trn

e_1 205.38 51.06501 3.01 3.01 6

f_3 -655.93 -855.7061 3.01 3.01 6

g_4 -655.93 -855.7061 3.01 3.01 6

h_6 -884.20 -1094.11 3.01 3.01 6

k_7 -884.20 -1094.11 3.01 3.01 6

Thanh Cnh Dia_2 508.36 335.2778 6 6 6a_5 1035.92 823.41539 6 6 6

a_8 1044.56 852.91416 6 6 6

2200

6000 6000 6000 6000 6000

2200 3

700


55/80



Trong : + l l khong cch gia 2 mt dn

+ loxl chiu di tnh ton trong mt phng khung.

+ loyl chiu di tnh ton ngoimt phng khung.

2. CHN TIT DIN CC THANH DN:

2.1 Thanh xin u dn:

* Chn tit din:

Tnh nh thanh chu nn ng tm vi N=-796.1477KN.

T N=796.1477KN>601KN ta chn b dy bn mt l 14mm.

Gi thit =80 =0.726.

Din tch tit din cn thit: 2796.1477

52.22. 0.726 21yc

NF cm

R.

mnh cho php ca thanh xin u dn chu nn l =120 do bn knh qun tnh yu cu ca

tit din:

0

0

1951.625 .

120

3903.25 .

120

xx yc

y

y yc

lr cm

lr cm

Chn tit din gm 2 thp gc khng u cnh L160x100x12, ghp theo cnh ngn, c cc c trnghnh hc sau:

- Din tch: F=60cm2.- Bn knh qun tnh: rx =2.82>1.625

ry =7.90>3.25

* Kim tra li tit din:

0

0

19569.15

2.82

39049.367

7.9

xx

x

y

y

l

r

l

r

Y

X12

14

160

100


56/80



Chn max( ; ) 69.15x y 0.782.

Kim tra n nh trong thanh: 2 2796.1477

16.97 21. 0.782 60

N KN KNR

F cm cm

Vy tit din chn m bo kh nng chu lc.2.2 Thanh bng:

a. Thanh 2_3

* Chn tit din

Thanh chu ko ng tm N=480.66 KN nn din tch yu cu c tnh theo cng thc.

2480.66 22.8921yc

NF cm

R.

mnh cho php ca thanh chu ko l =400 do bn knh qun tnh yu cu ca tit din:

0

0

1560.39 .

400

3900.975 .

400

xx yc

y

y yc

lr cm

lr cm

Chn tit din gm 2 thanh thp gc khng u cnh L100x63x8, ghp theo cnh ngn, c cc ctrng hnh hc sau:

- Din tch: F=25.2cm2

.- Bn knh qun tnh: rx =1.77>0.39

ry =5.12>0.975


19.07 2125.2

N KN KNR

F cm cm

Vy tit din chn m bo kh nng chu lc.

b. Thanh 4_5

* Chn tit din:

8

14

100

6

3

Y

X


57/80



Tnh nh thanh chu nn ng tm vi N= -283.6021KN.

Gi thit =100 =0.591.


22.85

. 0.591 21

yc

NF cm

R

.

mnh cho php ca thanh chu nn l =150 do bn knh qun tnh yu cu ca tit din:

0

0

172.41.15 .

150

4312.87 .

150

xx yc

y

y yc

lr cm

lr cm

Chn tit din gm 2 thp gc khng u cnh L100x63x8, ghp theo cnh ngn, c cc c trng hnh

hc sau:

- Din tch: F=25.2cm2.- Bn knh qun tnh: rx =1.77>1.15

ry =5.12>2.87


0

0

172.497.4

1.77

431

84.185.12

xx

x

y

y

l

r

l

r

Chn max( ; ) 97.4x y 0.608.


18.5 21. 0.608 25.2

N KN KNR

F cm cm


2.3 Thanh cnh:

a. Thanh h_6

* Chn tit din:Thanh chu nn ng tm viN=1094.11KN.

8

14

100

63

Y

X


58/80



Gi thit =100 =0.591.


88.156. 0.591 21yc

NF cm

R.

mnh cho php ca thanh chu nn l =150 do bn knh qun tnh yu cu ca tit din:

0

0

3012 .

150

6004 .

150

xx yc

y

y yc

lr cm

lr cm

Chn tit din gm 2 thp gc u cnh L200x12, c cc c trng hnh hc sau:

- Din tch: F=94.2cm2.- Bn knh qun tnh: rx =6.22>2

ry =8.69>4


0

0

30148.39

6.22

600

66.968.69

xx

x

y

y

l

r

l

r

Chn max( ; ) 66.96x y 0.792.


14.67 21. 0.792 94.2

N KN KNR

F cm cm


b. Thanh a_8

* Chn tit din

Thanh chu ko ng tm N=1044.56 KN nn din tch yu cuc tnh theo cng thc.

12

14

200

200

Y

X


59/80



21044.56 49.7421yc

NF cm

R.


0

0

600 1.5 .400

6001.5 .

400

xx yc

y

y yc

lr cm

lr cm

Chn tit din gm 2 thanh thp gc u cnh L100x14, ghp theo cnh ngn, c cc c trng hnhhc sau:

- Din tch: F=52.6cm2.- Bn knh qun tnh: rx =3>1.5

ry =4.76>1.5


19.86 2152.6

N KN KNR

F cm cm


3. TNH DN PHN NH:

Lc tc dng ln nt l nh nhau i vi tt c cc dn phn nh, ta xt tnh ton i vi dn c chiudi ln nht, l dn ngay ti chn ca mi.

Lc tc dng ln dn phn nh:

. 3 6( ) (0.36 0.453) 44.01

2 2m kcd B

G g g KN .

. 5.88 38.82

2 2

p dp KN.

44.01 8.82 52.83Q G P KN .

Ni lc trong cc thanh xin nh sau:

14

14

100

100

Y

X

26.41526.415

52.83

1 2

a

b c

c

a

b

1

2

5283

3684


60/80



Thanh ng 1_2: N=-52.83KN.

Thanh xin a_1: N= 36.84KN.

Cc thanh xin ny c ni lc nh nn ta s tnh theo cu to.

a. Tnh thanh ng:+ Chiu di tnh ton:

l0x=0.8l=0.8x1.4=1.12m

loy= l =1.4m

+ mnh yu cu:

0

0

1120.747 .

150

140 0.93 .150

xx yc

yy yc

lr cm

lr cm

Chn tit din gm 2 thanh thp gc u cnh L50x5, c cc c trng hnh hc sau:


ry =2.61>0.93

b. Tnh thanh xin:

+ Chiu di tnh ton:

l0x=0.8l=0.8x1.95=1.56m

loy= l =1.95m

+ mnh yu cu:


0

0

1560.39 .

400

1950.49 .400

xx yc

y

y yc

lr cm

lr cm

Chn tit din gm 2 thanh thp gc u cnh L50x5, c cc c trng hnh hc sau:


ry =2.61>0.49

vy trong mt dn phn nh chn tit din 2L50x5


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Loi thanhTn

ThanhN(KN) Thp chn

Dintch

(cm2)

Chiu di (m)Bn knhqun tnh

(cm)mnh

l(m) lox(m) loy(m) rx ryx y

Thanh xin u dn 1_2 -796.15 L160x100x12 60.00 3.9 1.95 3.9 2.82 7.9 69.15 49.367

Thanh bng

c_1 -44.87 50x5 9.60 2.2 0.88 2.2 1.53 2.61 57.52 27.85

2_3 480.66 L100x63x8 25.20 3.9 1.56 3.9 1.77 5.12 88.14 149.43

3_4 -105.64 50x5 9.60 2.8 1.12 2.8 1.53 2.61 73.20 54.69

4_5 -283.60 L100x63x8 25.20 4.31 1.724 4.31 1.77 5.12 97.40 165.13

5_6 92.05 50x5 9.60 4.31 1.724 4.31 1.53 2.61 112.68 84.18

6_7 -108.94 50x5 9.60 3.4 1.36 3.4 1.53 2.61 88.89 130.27

7_8 78.59 50x5 9.60 4.76 1.904 4.76 1.53 2.61 124.44 182.38

Thanh CnhTrn

e_1 205.38 80x8 24.60 3.01 3.01 6 2.44 3.84 123.36 229.89

f_3 -855.71 200x12 94.20 3.01 3.01 6 6.22 8.69 48.39 156.25

g_4 -855.71 200x12 94.20 3.01 3.01 6 6.22 8.69 48.39 69.04

h_6 -1094.11 200x12 94.20 3.01 3.01 6 6.22 8.69 48.39 69.04

k_7 -1094.11 200x12 94.20 3.01 3.01 6 6.22 8.69 48.39 69.04

Thanh Cnh Di

a_2 508.36 80x8 24.60 6 6 6 2.44 3.84 245.90 69.04

a_5 1035.92 100x14 52.60 6 6 6 3 4.76 200.00 156.25

a_8 1044.56 100x14 52.60 6 6 6 3 4.76 200.00 126.05

4. TNH TON CC CHI TIT TRONG DN:

Trong n ny ta s tnh ton cc chi tit chnh sau:

- Mt gi dn (2)- Mt khuych i nh dn (4)- Mt khuych i gia dn cnh di(5)


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- Mt trung gian c ni thanh cnh dn(3)- Mt trn u dn (1)

1.1. Mt gi dn (Nt 2):

Cu to mt gi bao gm bn mt (2), bn gi (1) v gi (3).

Cc thanh dn (gm thanh cnh di, thanh xin u dn) hi t ti mp trong ct trn v lien kt vobn mt bng ng hn sng(4) v ng hn mp (5).

Lc tc dng vo bn mt gm:Lc dc trong thanh cnh di : N1= 508.36KN

Lc dc trong thanh xin : N2= -796.15KN

Mment u dn : M=478.329KNm

Cc ng hn c tnh ton nh sau:

ng hn lin kt thanh cnh di vo bn mt:

Lc dc N1c phn ra lm 2 truyn vo 2 thp gc: 1 508.36

2 2

NN =254.18KN.

Thp u cnh nn:- ng hn sng lin kt thp gc chu 1 lc l 0.7N=0.7x254.18=177.926 KN.

Chiu cao ng hn: hmin= 4mm; hmax=1.2x8=9.6mm

1

2

34

5 5

7 89

610

1112

13

14

15

BU LONG

2L80 x8

2L160x100x12

3

3

2

4

51

4


63/80



Chn hhs=8mm => Chiu di ng hn sng cn thit l:

177.92621

( . ) (0.7 0.8) 15hs ghh h h

Nl cm

h R

-

ng hn mp chu 1 lc l 0.3N= 0.3x254.18=76.254KN

Chn hm=6mm => Chiu di ng hn mp cn thit l:

76.25412

( . ) (0.7 0.6) 15hm ghh h h

Nl cm

h R

ng hn lin kt thanh xin u dn vo bn mt:

Thp khng u cnh nn t l phn b lc gia ng hn sng v ng hn mp l 0.75/0.25.

Chn hs=10mm => Chiu di ng hn sng cn thit l:

2/ 2 796.15 / 20.75 0.75 28.43( . ) (0.7 1) 15hs gh h h

Nl cm

h R.

Chn hm=6mm => Chiu di ng hn mp cn thit l:

2/ 2 796.15 / 20.25 0.25 15.79( . ) (0.7 0.6) 15hm g

h h h

Nl cm

h R

Tnh ton sn gi 1:

Phn lc ng ti gi truyn vo lin kt hn gia bn mt v bn gi c gi tr bng

N2.sin=796.15.sin450=562.96KN.

Chn b rng sn bbg=200mm. Vi b dy bn gi 18bg mm , ta kim tra iu kin chu p mt cabn gi

2 2

562.9615.637 35

20 1.8em

em em

em

N KN KN R

F cm cm

B dy sn c xc nh nh sau:

Nu quan nim bn gi nh mt bn ngm 2 cnh l 2 hng bulong, chu lc nh H th b dy bngi c xc nh theo cng thc:

1

3. .1 1 3 10 217.4221.32 . 2 46 21

bg

b Hcml R

Trong b1l khong cch gia 2 hng bulong, ly bng 10cm

Mt khc 20s mm do ly 20s mm

Kim tra lin kt hn gia bn mt v bn gi:

Thay th moment u dn bng 1 cp ngu lc c g tr:

0

478.329217.422

2.2ngM

N KNh

.

cnh di, lc trng vi trc thanh cnh di, hng t tri qua phi, c xu hng tch bn gi cttrn. Khi di v trng tm lin kt ta thu c mt lc ngang H=217.422KN v mt moment

M=(N1-Nng) x e=(508.36-217.422)x0.05=14.547KNm.


64/80



Phn lc ti gi truyn vo lin kt hn gia bn mt v bn gi c gi tr bng:

R= N2.sin= 796.15x2.5

3.9=510.353KN.

Vi hh= 50cm, ta tnh c chiu cao ng hn cn tit nh sau:

2 22 21 1 1454.7217.422 510.35

2 2 0.7 46 15 46lt

h h

h h g h

Mh H R

l R l x x x=0.59cm.

Chn hh=10mm. Cc c trng hnh hc ca 2 ng hn nh sau:

- Din tch: Fh=2(h.hh)lh= 2(0.7x1)x50=70 cm2.- Moment khng un: Wh= 2 2 3. 0.7 1 502 2 583.33

6 6h h h

h lcm

Kim tra cng ng hn:

2 2 2 21454.7 217.422 510.35

583.33 70 70h h h

M N Q

W F F=9.193

2

KN

cm


65/80



Cc ng hn lin kt gi vo ct bao gm 2 ng hn 2 bn gi v 1 ng hn mp di chu 1 lc: 1.5RA=1.5x510.35=765.525KN

Chn hs=10mm => chiu di ng hn cn thit l:

765.525 72.9( . ) (0.7 1) 15h g

h h h

Nl cmh R

. Vy chiu di 2 ng hn bn l 25cm.

1.2. Mt trn (Nt 1):

Tng t nh mt gi, cu to mt trn bao gm bn mt, bn gi

Lc tc dng vo bn mt bao gm:Lc dc trong thanh cnh trn :N1=205.38KN

Lc dc trong thanh cnh xin dn phn nh :N2=36.84 KN

Thp moment m ln nht u dn :M2=-449.59 KNma)Tnh ng hn lin kt thanh cnh trn vo mt:Chiu cao ng hn:hmin=4mm; hmax=1.2x8=9.6mm


1/ 2 205.38 / 20.7 1 0.7 1 12.41( . ) (0.7 0.6) 15hs g

h h h

Nl cmh R

Chiu di ng hn mp cn thit l:

1/ 2 205.38 / 20.7 1 0.3 1 5.89( . ) (0.7 0.6) 15hs g

h h h

Nl cm

h R

b)Tnh ng hn lin kt thanh xin u dn vo mt:Chiu cao ng hn: hmin=4mm; hmax=1.2x5=6 mm


BAN MAT

50 x 5

80 X 8


66/80



2/ 2 36.84 / 20.7 1 0.7 1 3.45( . ) (0.7 0.5) 15hs g

h h h

Nl cm

h R


2/ 2 36.84 / 20.3 1 0.3 1 2.05( . ) (0.7 0.5) 15hm g

h h h

Nl cm

h R

c)Tnh ton sn gi:Chn b rng sn bs=200mm

Thay th moment u dn bng mt cp ngu lc c gi tr:

0449.59 204.3592.2ng MN KNh

Khi di lc do moment ngu lc v trng tm ta thu c mt lc ngang

H=204.359 KN hng t phi sang tri v mt moment :

M=H x e=204.359x0.05=10.218KNm.

B dy sn gi c xc nh nh sau:

131 1 3 10 204.359

1.6752 . 2 26 21bgb H

cml R

Trong b1l khong cch gia 2 hng bulong, ly bng 10cm

Mt khc 20s mm do ly 20s mm

Kim tra lin kt hn gia bn mt v bn gi:

Lc dc trong thanh xin dn phn nh truyn vo lin kt gia bn mt v bn gi:

2

1.5.cos 36.84 31.045

1.78pnR N KN.

Vi lh=26cm, ta tnh c chiu cao ng hn cn thit nh sau:2 2

2 21 1 1021.8204.359 31.0452. . . 2 0.7 26 15 26

lth pnh

h h g h

Mh H N

l R l=0.45cm

Chn hh=8mm. cc c trng hnh hc ca 2 ng hn nh sau:

- Din tch: Fh=2(h.hh)lh=2(0.7x0.8)x26=29.12cm2.- Moment khng un: Wh= 2 2 3( . ) (0.7 0.8) 262 2 126.187

6 6h h h

h lcm

Kim tra cng nghn:


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2 2 2 21021.8 204.359 31.045

126.187 29.12 29.12h h h

M N Q

W F F=15.15

2

KN

cm.

chch lch15.15 15

100% 0.99% 5%

15.15

Kim tra iu kin p mt gia bn gi v gi :

Lc p mt: Nem=Rpn= 31.045KN

Cng p mt:

2 2

31.0450.776 35

20 2em

em em

em

N KN KN R

F cm cm

Tnh ton lin kt bulong bn gi vo cnh ct trn:

Chn b tr 2 hng bulong , mi hng gm 2 bulong nh hnh v, bulong c chn c bn thuclp 5-6.Lc ln nht xut hin trong thn bulong:

1max 2 2 2

. . 204.359 5 20 204.359

2 2 10 20 6bl

i

H z l HN

l n=54.5KN.

Din tch qua ren ca bulong:

2max 54.5 2.59521

bl

th

bl

NF cm

R.

Chn bulong 24, c Fth=3.52cm2.

1.3. Mt nh dn (Nt 4):

Cu to mt nh dn gm bn ph (1), bn mt(2),bn ni (3)v 2 sn ng(4)

Gc nghing ca thanh cnh so vi phng ngang l = arctan(1/10)=5.710.

Gc nghing ca thanh xin so vi phng ngang l =arctan(3.7/3)=50.90.

a.Ni cnh:Lc dc trong thanh cnh: Nct= -1094.11KN

BAN MAT

5

32

41


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Lc dc trong thanh xin: N tx=78.59KN.

Lc tnh ton: Ntt=1.2Nct=1.2x1094.11=1312.932 KN

Din tch tnh ton quy c:

Bn mt dy 14mm, ni 2 thp gc L200x12, do chn bn ph c tit din 440x10mm.

Khi din tch tnh ton quy c c tnh nh sau:

Ftt = Fbm + Fbp = 2 x1.2x20+44x1= 92cm2.

ng sut trung bnh trong tit din tnh ton quy c:

2 2

1312.93214.27 21

92tt

tb

tt

N KN KN R

F cm cm

lc truyn vo bn mt: Nbm=tb.Fbm=14.27x48=684.96 KN.

Kim tra cng ng hn lin kt thanh cnh trn vo bn mt:Thp u cnh nn:

ng hn sng lin kt thp gc chu lc 1 lc l Ns= 0.7Nbm=0.7x684.96=479.472 KN.

Chiu cao ng hn: hmin=4mm ; hmax=1.2x1.2=1.44cm


/ 2 479.472 / 219

( . ) (0.7 1.2) 15s

hs g

h h h

Nl cm

h R

Chn hhm =8mm => Chiu di ng hn mp cn thit l:

/ 2 684.96 / 20.3 0.3 12.23

( . ) (0.7 0.8) 15bm

hm g

h h h

Nl cm

h R

Ly chiu di ng hn sng l 21cm, chiu di ng hn mp l 15cm.

Tng din tch ng hn:

Fh=(h.hh)lh=2(0.7x1.2x20+0.7x0.8x14)=49.28 cm2.

ng sut trong ng hn c kim tra nh sau:

2

684.9613.9

49.28bm

h

h

N KN

F cm


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Bn ni c lin kt vi bn ng bng 2 ng hn ng c lh=39cm, chn hh=6mm

ng sut trong ng hn:

2 2

741.03911.31 15

4 (0.7 0.6) 39

bn

hh

N KN KN R

F x x cm cm

1.4. Mt gia didn (Nt 5):

Ngoi cng trng dn s c khuych i nh sau:

- Ta stnh ng hn lin kt thanh cnh s8 vo 2 phn cn khuych iLc dc trong thanh cnh: N3=1044.56 KN

Lc tnh ton: Ntt= 1.2Ncd =1.2x1044.56=1253.472 KN

Din tch tnh ton quy c:

Bn mt dy 14mm, ni 2 thp gc L100x14, do phi chn bn ph c tit din l 250x14mm.

Khi d din tch tnh ton quy c c tnh nh sau:

Ftt= Fbm+Fbp =2x1.4x10 +25x1.4=28+35=63cm2.


2 2

1253.47219.896 21

63tt

tb

tt

N KN KN R

F cm cm

Lc truyn vo bn mt: Nbm= tb.Fbm=19.896x28=557.088 KN

Kim tra cng ng hn lin kt thanh a_8 vo bn mt:

Thp u cnh nn:

Chiu cao ng hn: hmin=4mm; hmax=1.2x14=16.8mm.

Chn hh=8mm => Chiu di ng hn sng cn thit l:

/ 2 557.088 / 20.7 1 0.7 1 24.25

( . ) (0.7 0.8) 15bm

hs g

h h h

Nl cm

h R.

Chiu di ng hn mp:Chn hh=6mm

8

nut nh

nut di


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/ 2 557.088 / 20.3 1 0.3 1 14.26

( . ) (0.7 0.6) 15bm

hm g

h h h

Nl cm

h R

Ly chiu di ng hn mp l 15cm

Tng din tch ng hn:

Fh = (h.hh)lh =2(0.7x0.8x24+0.7x0.8x12)= 40.32 cm2.

ng sut trong ng hn c kim tra nh sau:

2 2

557.08813.817 15

40.32bm

h

h

N KN KN R

F cm cm

Lc truyn vo bn ph: Nbp= tb.Fbp =19.896x35=696.36 KN

Kim tra lin kt gia bn phv thp gc cnh:

Chn hhm=12mm, tng chiu di ng hn lin kt bn ph vi thp gc cnh l:

min

696.364 4 60

( ) . (0.7 15) 1.2bp

h

g h

Nl cm

R h

Chn chiu di ng hn ngoi dc theo mp thp gc l 15cm, hh=12mm; ng hn xin l 15cm,chiu cao ng hn hh=12mm.

Tng din tch ng hn:

Fh=(h.hh)lh=2(0.7x1.2x15+0.7x1.2x15) = 50.4cm2

.ng sut trong ng hn c kim tra nh sau:

2 2

696.3613.82 15

50.4bp

h

h

N KN KN R

F cm cm

- Tnh lin kt thanh bng vo bn mt:Thanh a_5: N= 1035.92KN.


2 21035.92 16.44 21

63tt

tb

tt

N KN KN RF cm cm

Lc truyn vo bn mt: Nbm= tb.Fbm=16.44x28=460.32 KN

Kim tra cng ng hn lin kt thanh a_5 vo bn mt:

Thp u cnh nn:

Chiu cao ng hn: hmin=4mm; hmax=1.2x14=16.8mm.

Chn hh=0.8mm => Chiu di ng hn sng cn thit l:

/ 2 460.32 / 20.7 1 0.7 1 20.18( . ) (0.7 0.8) 15

bmhs g

h h h

Nl cmh R

.


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Chiu di ng hn mp:Chn hh=6mm

/ 2 460.32 / 20.7 1 0.3 1 11.96

( . ) (0.7 0.6) 15bm

hm g

h h h

Nl cm

h R

Ly chiu di ng hnsng 21cm, ng hn mp l 12cm

Lc truyn vo bn ph: Nbp= tb.Fbp=16.44x35= 575.4 KN

Kim tra lin kt gia bn phv thp gc cnh:

Chn hhm=12mm, tng chiu di ng hn lin kt bn ph vi thp gc cnh l:

min

575.44 4 50

( ) . (0.7 15) 1.2bp

h

g h

Nl cm

R h

Chn chiu di ng hn ngoi dc theo mp thp gc l 15cm, hh=12mm; ng hn xin l 10cm,chiu cao ng hn hh=12mm.

Thanh 5_6: N= 92.05KN.


/ 2 92.05 / 20.7 1 0.7 1 7.14

( . ) (0.7 0.5) 15s

hs g

h h h

Nl cm

h R

Chiu di ng hn mp cn thitl:/ 2 92.05 / 2

0.3 1 0.3 1 3.63( . ) (0.7 0.5) 15

mhm g

h h h

Nl cm

h R

Ly chiu di ng hn sng 8cm, ng hn mp l 5cm

Thanh 6_7: N= -108.94KN.


/ 2 108.94 / 2

0.7 1 0.7 1 8.26( . ) (0.7 0.5) 15s

hs gh h h

N

l cmh R


/ 2 108.94 / 20.3 1 0.3 1 4.11

( . ) (0.7 0.5) 15m

hm g

h h h

Nl cm

h R

Ly chiu di ng hn sng 9cm, ng hn mp l 5cm

Thanh 7_8: N= 78.59KN.

Chn hhs=5mm => Chiu di ng hn sng cn thit l:/ 2 78.59 / 2

0.7 1 0.7 1 6.2( . ) (0.7 0.5) 15

shs g

h h h

Nl cm

h R

8/12/2019 Do an ket c

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