7/29/2019 PC Structure Lecture8

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Kt cu B Tng F2

Prestressed Concrete Structures

Trng i hc Giao thng Vn ti Vin KH&CN XDGT

Ging vin: Phm Hong Kin

E-Mail:phamkien2003@gmail.com

Phone : 0975-474-828

CHNG 8: THIT K KHNG CT V XON

1. Giithiu chung

2. Thitk khng ct

3. Thitk khng xon

mailto:phamkien2003@gmail.commailto:phamkien2003@gmail.com

7/29/2019 PC Structure Lecture8

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Thitk khng ct

Vtntcto thnh vung gc viphngcangsut ko

chnh

Vtnt nghing:

Hnh thnh ni c lccttngiln

Hngcangsut ko chnh nghing gc so vitrcdcca

cukin

Vtnt nghing c phn thnh hai loi :

Vtntctsn: xuthin trong sndm nhngni b

tng chuct l chyu

Vtntunct: BT chungthilcct v m men unln

Thitk khng ct

7/29/2019 PC Structure Lecture8

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Thitk khng ct

Tiuchun

ACI 318-05Sckhngctsn 0,29 0,3cw c pc w p pV f f b d V

lcct do dnglc gy ra

khong cch t mp chu nn ntrng tm ctdnglc v khng clynhhn 0,8h v bw

Sckhngunct max

0,05 MPaici c w p p cr V

V f b d V M M

M men gy nt 0,5cr c pe t

IM f fy

ciV khng clynhhn 0,14 c wf b d

Sckhngctcamtctb tngmin

ci

c

cw

VV

V

Thitk khng xon

Tnh ton m men xon gy nt

Cngnh khi chuct, dnglc lm tnglnca m men

xon gy ntcukin thng qua vic lm gimngsut ko dc

trc.

Mtctbtk: c tnh ton trn sng thnh mngtng

ng

ngsuttip do m men xon

Cc vtnt nghing do xonsxy ra khi ngsut ko chnh t

ncngchu ko dctrc

3

4

cp

cp

cp

At

p

2

cp

cp

Tpv

A

0,33 MPacr cf f

2

0, 33 1

0,33

pcccr c

c c

fAT f

p f