Đồ án thiết kế môn học cầu bê tông Thiết kế nhịp cầu bê tông cốt thép dự ứng lực, chiều dài nhịp 26m, khổ cầu 10m

ThiÕt kÕ m«n häc cÇu Btct :

• 
• 
•  !"#$%&'(&)*($+'((, 


• /0,123$4!!13$!"5
• 264!!178$97:Φ
• ;0<=!>$((
• 26?!@!A
• B$C$
%
%
×2.1
  !"# 

38D2E49/!C#
• F4G
• 2 $0$AC0G
• C2G
1,20(m).h
25
1
15
1
L
h
=→÷=
• C2E+<÷(9HI<*
• I< 


*÷9HI


• J!5<#KDL
• "M$0!J!20<

*(
;?!@!$C$GCB6$EC

;?!@!$C$GC9CCB6$ECN
I.1/ KÝch th íc mÆt c¾t ngang quy ®æi .
• I< 0OIP
"2$PB<

*(N<*N

NQ

((:((


Q

*(((


( )
21
2

1
FF
b
h
c
c
+=

Q

R/!J0
Q

R/!JDS!0
• C2<OIP
( )
54
1
1
.2
1
FF
b
h +=
"2$PB<

'"M$<

Q


R/!JGC<
Q
:
R/!JDS!<
Q

'*''*


Q
:
(TT:(


CIE4D2!CB

:('
I.2/ To¹ ®é träng t©m cèt thÐp d øng lùc so víi ®¸y dÇm 
R7P<4!"JT<B4!!1DPU<4!"JKDL
).(20
10
3828.318.38.3
3
4
cm
y
a
t
=
+++

=
+++
==
∑
∑
10
3.y.y3.y
n
yn
321
i
ii
'
I.3/ TÝnh hÖ sè ph©n bè ngang :

.
.I'.ΔI6E
d
α
n
3
=
V5
a
I
n
I
=
′


dd
4
I384.E
5.l
Δp =
CID2!CB
(*) .
.lI
.a.I12,8d
.5.l.I6E
I.a.384.Ed
α
4
n
d
3
4
nn
dd
3
==
"2$PB
9,WPM!J!20GCN:
X

X

;>PY#$C$9HIX

X



Z

;>[O0!JGC#G
Z

;>[O0!JGC$C$
2 $0$ACC#GN
C2 $0$ACC$C$NC(*
I.3.1/ TÝnh I

:
• R/!J?!@!@!$C$G>$!J/!J4!!1
Q*(:(''**


• ;>[!\GC!]!/P4D51!"=< 0
120.71,4.10.8,485,99.36.3,4045,48.18.5,62
2
2,17
.2,17.180 +++=S
)(2,248602
3
cm=
• V!"J!"#$!^!]!/
I
(

43,83(cm).

5671,8
248602,2
F
S
==
• ;>[O0!JGC!]!/P4D5!"_POC!"#$!^!]!/

2
tt0t
2
1
01
3
1b
2
c
1c
3
1c
2
c
0c
3
cc
d
)ay-(H.F
)
2
h
y-(H.h

12
.hb
)h
2
h'-H
).(-hh' (H
12
)-hh'-b.(H
)
2
h'
(y.h'
12
.h'b
I
−+
−++−+
−
+
+−+=
n
by
h
b
b
bc
c
0
1
'

:

).(cm43,83)201(12010.4,8.4,7
43,83)
2
40,3
06.40,3.(12
12
36.40,3
3
43,83)17,2
2
62,5
18.62,5(
12
18.62,5
)
2
17,2
43,83 180.17,2(
12
180.17,2
I
42
2
3
2
3
2
3

d
1,9925795
3
=−−+
−−++−++
+−+=
I.3.2/ TÝnh I

:
ëP^IC20!7CD2CPB!]!/$C$B6$KA`!
#,J!5!]!/KDL
).2,350890
4
3
n
cm
12
15.67
I ==
CIZ

DZ

D2a!CB
005,0041,0
2,350890.4.25
1,9925795.08,5.1,2.8,12
4
3
>==

α
V5α((:b(((=!C!J/E4^<4$C$![2c$0^4P
Y
dMEI$AC!"E4α((:Dα((R2<=<H!9UH!=!Ce!J/
E4^<4$C$2<=
]!O 
3653.0
6623,0
1747.0
01
00
02
=
=
=
p
p
p
R
R
R

1440.0
00041,0
05
04
−=
−=
p
p

R
R

1093,0
3101,0
60
00
−=
=
M
M
dR
dR
$fg%!6PS!!hCi0P![2>$!8
)(d
d
dk
RR
M
n0
p
0n
p
0k
+=

V5

p
n

R
0
j 97$4,j!0_$!6$4<=

M
n
dR
0
 97$4,>[cD;!0_$!"=$4<=

d
dk
kE4$ACP26l$!"=GC$C$
CB
d
dk

5,0
1,2
05,1
=
CID2>$!8!"=!CB
8174,03101,0.5,06623,0
0
=+=
P
k
R
1987,0)1093,0.(5,01440,0
'0

−=−+−=
P
k
R

(
  '
:
m
%'(
%'(
)*(
(*:
(*(
('
(''
(:T
(::
(''
(:
(**'
(:
(('
&((((:
&(::(
&(T*
fg%n
(
(


(
:
T T

(
(
fg% 97GC<=K<=
J/E4^<4$C$
2$+P<Mei]! $+PM!<=DK<H!9UH!

0057,17,0.
2
5633,06623,0
8,0.
2
6623,07805,0
=
+
+
+
=
N
η
• 226!! %'(

4791,0)0163,01747,02745,04926,0(
2
1
30
=+++=

H
η
• 226!! )&*(

3299,0)1883,04714,0(
2
1
80
=+=
XB
η
!JM972?!@!!6$4!Co$/E4^<4$C$!J![2c$0
Pp<WI!CB

5357,1=
N
η

7381,0
30
=
H
η


5,0
80
=
XB
η

$%&'()*+
III.1/ TÜnh t¶i giai ®o¹n I:
• R#G
)./(5,2).
5
1
( mTFFq
mnt
∑
+=
"2$PB
Q&R/!J?!@!$C$GCM!G]!62!"2$0IQ*(


ΣQ

$/!J44!7/!6/!"+$
JQ

0EC,]!62!K!"=< 0Pq4!!1+EC,"C
>$!"+$EL!]P<=!>$Pq4!6$2ELB:44
$AC0GD5CD5,J!5449'(d$2"CC<=
Pl$pP!=9
R/!J449ΣQ

:'((



)./(53045,110.5,2).2250

5
1
8,5671(
4
mTq
t
=+=
−
• R$C$
C<4!"J!2B:($C$,2 $0$AC0$C$9(*
&"#$9U$!2<M$C$
O

((:(TT((:*
$C$9&(*T
"#$9U$" P2!"=9

)./(0709,0
5.4,25
0048,9
' mTq
t
==
\! $C26Z9
)./(6014,10709,053045,1' mTqqq
tt
I
t
=+=+=
III.2/ TÜnh t¶i giai ®o¹n II:

C2$YCC9$+P$+@<095G?!
• "#$9U$$+@<0
)./(1392,04,2.29,0.2,0 mTP
g
==
• "#$9U$9$+P
)./(15,05,2.06,0
2
mTP
l
==
• "#$9U$9CC!CID
4!"J0M!9CC0C'r<=BTM!
q!JM!9CC!CID
3
1
1655,126).12,0.1,012,0.2,0(9.15,0.2,0).35,02,1( mV =++−=
q!JPs9CC
3
2
275,226.35,0.25,0 mV ==
"#$9U$9CC!"=9

)./(3308,0
26
5,2).(
21
mT
VV
P

lc
=
+
=
• "#$9U$95G?!

5<=!>$CEtCI9(('(.


5<=!>$< 2MI'9((':((.


5p$5I9((((.


59I/I9(((('.


$j
!
('T.


• JO

O

j
9
I

9

ttngnggg
PPyP
ωω
++

mTyP
lclc
/2004,0)1922,07980,0(3308,0. =−=

mTyP
gg
/066,0)1030,0774,0(1392,0. =−=

mTP
gng
/1195,05,1).
2
0961,01857,0
2
5633,07805,0
(15,0. =
+
−
+
=
ω

mTP

tt
/3612,0)0961,0.405,1.
2
1
5633,0.595,5.
2
1
(2395,0. =−=
ω
(:
(*:
(T*(
('
(*(
(''
(:
(''
j
$
(''(*.
 :
((((:
j
$
(.
j
$
('T.
j
$

('T.
(T*
(T
((T
(('(
(::(
(*
fg%n
(
: i
"#$9U$!\! $CP26ZZ
)./(7471,03612,01195,0066,02004,0
2
mTq =+++=
,-%./ 0  
i0PM97u?!@!P?!"$
6$4N0$4ND!"J9.:ND!"J9.'ND?!@!$AC9.
IV.1/ HÖ sè xung kÝch :
CBµ'd]≥λ
µd]λ≥:
V5:MEI$0"!"=!CBµ:
IV.2/ T¶i träng t ¬ng ® ¬ng cña H 30 vµ XB 80
"C< $! !"#$!c$Pc$!CB
*
;?!@! d$v+ %'( )*( ;?!@! d$v+ %'( )*(
i (:(( * C$4 (:(( T:( *(
i9.: (:(( *( (( i (:(( ' T(
i9.' (:(( '* (( i9.: (:(( T* ''
i9. (:(( ((( (( i9.' (:(( '(T: **
i9. (:(( 'T( ((

Tơng ứng với đờng ảnh hởng mô men Tơng ứng với đờng ảnh hởng lực cắt
b ảng tra tải trọng tơng đơng của hoạt tải tại
các mặt cắt đặc trng
T
IV.3/ Nội lực tiêu chuẩn và nội lực tính toán do các tổ hợp tải trọng đ ợc xác định và
lập thành các bảng sau đây :
(Bảng 1)
l
(m)
x
(m)
l-x
(m)
y
y
1
y
2
w
(m
2
)
w
1
(m
2
)
w
2
(m

2
)
: * T ( '

;

: (( 'T( : T' T

;

: '( T( :' (:* (:*:
'
;
'
: *: T' :: * *:
:
;
:
: (( ( '( *( *(:

w
(
%
(
:
(((( :( ( ( ((

w

: (( 'T(

(T:(T ((T
:: &((:: ((

w

: '( T(
((( (
:: &(T: '(
*
w
'
: *: T'
( (''''
:: &: :''
T
w
:
: (( (
(((( (
' &' ((((
!12'1/
Các trị số để tính diện tích Đ.A.H Diện tích Đ.A.H
'
Dòng
Nội
Lực
Dạng đờng ảnh hởng


i

9
I
I

i
I

I

(
$
w

!
w

!
w
!
w

!!
w

!!
w
!!
': ' *T ': '
' : * T ( '

;

T (: (: * ''T :( '* ((T

;

(:*: (: (: T* :T :( (: * :''
'
;
'
*: (: (: :*( ' *' * *('' (
:
;
:
*(: (: (: T: ( *T'T :( T(' ':'

w
(
%
(
(( (: (: (': T:T T*' ' :' '(

w

(( (: (: T: *' '( T' '*

w

'( (: (: ( :: :T T *'(
*

w
'
:'' (: (: * ' TT: : :: (
T
w
:
(((( (: (: ((( ((( ((( ((( ((( (((
Dòng
của
bảng
1
Nội
lực
Xác định nội lực do tĩnh (tải tiêu chuẩn và tính toán)
Tĩnh tải tiêu chuẩn Hệ số vợt tải Do tĩnh tải tiêu chuẩn Do tĩnh tải tính toán
Cột 13
của
bảng 1
(m
2
)
O

.
O

.

(B¶ng 3)
HÖ sè lµn
  ' :    * T (   ' : 

;

(:  * (( (:T ('TT (T * T**( ':::

;

(: *( (( (( (:T ('TT (T '' *( '*
'
;
'
(: '* (( (( (:T ('TT (T ':: ( ':T'T
:
;
:
(: ((( (( (( (:T ('TT (T ':T '' *(

w
(
%
(
(: T:( *( ' ('* (((( (T * * ':

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f?!"$K#GC!]!/$I=,4B4!!13$!"5,P<=!>$FC
,3$4!!1!K!2<M!]!/EL!C$C970P?!"$GC!]!/
OIP!c$Pc$
• R/!J?!@!$C$OIP
Q!P
ttcc
Fnhbbhbbhb .).().(.
11
+−+−+
• ;>[!\GC!]!/P4D5P0I
F
i

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c
cc
aFn
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h
hhbb
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2
).(
)
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2
.
2
11
2
+
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• 2 $0!h!"_O0!JJGC!]!/!5Pe

td
x
I
d
F

S
y =
D
I
t
I
t
yhy −=

• ;>[O0!JGC?!@!OIP
12
).(
)
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).(
3
).(
3
).(
3
11
2
3
33
hbb
h
yhbb
hbbybyb

I
c
I
tcc
cc
I
d
I
t
td
−
+−−+
−
++=

( )
2
2
1
11

2
.).(
t
I
dtt
I
d
ayFn
h

yhbb −+






−−+
"2$PB
<<IE+(


<I0
<

"M$0*(
<
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
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I
t
a
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yyyy

n
yn
4321
i
ii
9,610,78,5
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a
I
t
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==
∑
∑

cm30,37
10
8.218.228.242,4316,577517,89
=
++++++
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ZV&ZV ((( *T*((:T:':( * : T:(
Z&Z ''( *T*((:'(:( * ::T T'TT(
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VII.2/ Tính ứng suất trong cốt thep DƯL tại mặt cắt giữa dầm.
VII.2.1/ Mất mát ứng suất do ma sát . (

5
)
>$!8


f.d
f.P



cos
sinf
kt
"2$PB

,!
&8$EH!,q!"C#
,!
(((,

j&!GCM974!!14i=9=<MPDPq4
t&/E4CE0!$AC4!!1D<MPDNt('
Q

&/!J!]!/<B4!!14i=
C!JH!0!8$EH!2!h$<B
).
cm
kG
198,7(
0,9982
0,0601
0,3.11000.
2
1
5
==
).
cm
kG
181,8(
0,9985
0,0551
0,3.11000.
2
2
5
==
).
cm

kG
235,2(
0,9975
0,0711
0,3.11000.
2
3
5
==
).
cm
kG
(
0,9979
0,0642
0,3.11000.
2
4
5
3,212==

HI

98$EH!!"$<KH!0!20<B4!!1Rz

)
cm
kG
(
2

8,82
10
828
5
5
===

n
i



VII.2.2/mất mát ứng suất do chênh lệch nhiệt độ



(

$.

D5

(
"2$PB
(
∆&=9//!PM!"2$<Y$HcB$< 2s$<=!>$D/!
PM<=$2,>$,J
d/!PMHB$(
(


d/!PM,>$,J'(
(
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V`I∆'(
(
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(∆
(

σ

('((, 

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VII.2.3/mÊt m¸t øng suÊt do tù chïngσ
'
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'
(
TC
d
d
R
σ
&(σ


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"2$PB
σ
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&8$EH!4!!1B!JP]H!0!8$EH!iH!/!"5,1
<=!>$
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σ
,!
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(((&**(&'(((.
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HIn
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!
(((, 
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'
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

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:
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σ
:
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l
l
d
∆
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
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9
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σ
:
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).
cm
kG
276,8(.1,8.10
26,0136.10
0,4
2
6
2
=
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d
E
E
ϕ
i
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i
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:
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d

σ
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&σ
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:
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
&σ
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Q
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:*-
σ
<
d


td
F
1

td
2
I
y


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II

Z
&C

*&(*
σ
<
:*
5898
1

9755145,1
57,85
2
', 

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!1
Φ_!MD2P?!"$!h<]4o$ϕ
i
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t
ρ
2

2
r
y
D5"
td
td
F
I
⇒ρ
td
2
I
y
td
F.

0234,3
5898.
=
9755145,1
57,85
2



b
t
E
E
t&/E49U$4!!1Q


!"2$?!@!<=!>$Q
<

t
b
d
F
F
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5671,8
47,1
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ρ

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"C< $&!CB
ϕ
i
Nρ

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ϕ
i
Nρ

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dMEI!CBN
ϕ
i

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CI0E4D2!CB
σ

σ

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
':*(*(:*:, 


VII.2.6/mÊt m¸t øng suÊt do bª t«ng bÞ nÐn ®µn håiσ


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b
n
σσ
.
7
=
"2$PB
8,4==
b
d
E
E
n

2
/1,232 cmkG
b
=
σ
)/(1,11141,232.8,4
2
7
cmkG==
σ

VII.3/ Tính ứng suất trong cốt thep DƯL tại mặt cắt cách tim gối

VII.3.1/ Mất mát ứng suất do ma sát

>$!8


f.d
f.P



cos
sinf
kt
"2$PB

,!
&8$EH!,q!"C#

,!
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t&/E4CE0!$AC4!!1D<MPDNt('
Q

&/!J!]!/<B4!!14i=
R2!6?!@!Z&Z04!!1#G<,12!{$D,>$pOC<MPDPq
4=

(
VII.3.2/mất mát ứng suất do chênh lệch nhiệt độ




(

D5

(
"2$PB
&=9//!PM!"2$<Y$HcB$< 2s$<=!>$D/!
PM<=$2,>$,J
d/!PMHB$(
(

d/!PM,>$,J'(

(

V`I'(
(



(
(



('((,


VII.3.3/mất mát ứng suất do tự chùng
'

>$!8

'
(
TC
d
d
R

&(

"2$PB


&8$EH!4!!1B!JP]H!0!8$EH!iH!/!"5,1
<=!>$



,!
&

&

(((&'(((((,


HIn

!
(((,



'
(
17000
10700
&((((:*',

VII.3.4/mất mát ứng suất do biến dạng neo, biến dạng bê tông dới
neo
:

>$!8

:

d
.E
l
l
"2$PB
'
X

&>PPYGC!1+$PMC2X

*(

, 


∆9&!$<]6$[2<]6$<=!>$5[29HI![2_9_OI!"K
TTo$[2∆9(:
9
!<
&!"$<KGC4!!19
!<
('

CID2!CB
σ
:

).
cm
kG
276,8(.1,8.10
26,0136.10
0,4
2
6
2
=
VII.3.5/mÊt m¸t øng suÊt do bª t«ng co ngãt vµ tõ biÕn:σ

σ


>$!8
σ

σ

ε

X

σ
<


b
d
E
E
ϕ
i
Φ
"2$PB
ε

Nϕ
i
&!"E4$56GC<]6$2$B!!c$P4GCP?!"$!h<]B
_!M!GC<=!>$,<1!"50<=!>$DP,/20"@
HIϕ
i
Dε

(((((
σ
<
&8$EH!GC<=!>$u!5OC!"#$!^GC4!!1PC$i1!2RzPy
i1!0H!0!8$EH!σ
'
σ
:
σ

σ


d

σ
,!
&σ
'
&σ
:
&σ

&σ

Q

(((&:*'&*&'((:
:*',-
σ
<
d


td
F
1

td
2
I
y


V5I&,2 $0!h!"#$!^4!!1P]!"_POC!"#$!^!]!/
II

Z
&C

*&'':
σ
<
:*'
5898
1

9367699,6
(41,21)
2
TT, 


Φ &E4i1!!5 u$GCO0!"K2$B!D!h<],12GC<=
!>$!5!"E48$EH!C2_!i0Pu< $&$02!"K<=!>$4!
!1
Φ_!MD2P?!"$!h<]4o$ϕ
i
D!JE4ρ

t
ρ
2

2
r
y
D5"
td
td
F
I
⇒ρ
td
2
I
y
td
F.

069,2
5898.
=
936799,6
(41,21)
2



b
t
E
E
:*

t&/E49U$4!!1Q

!"2$?!@!<=!>$Q
<

t
b
d
F
F

5671,8
47,1
(((*'
ρ.

t(T:*(((*'((*:
"C< $&!CB
:
ϕ
i
Nρ

t(( Φ(T*
ϕ
i
Nρ

t(( Φ(*:
dMEI!CBN

ϕ
i
Nρ

t((*: Φ(*'
CI0E4D2!CB
σ

σ

(((((*(

TT:*(*'(*, 


VII.3.6/mÊt m¸t øng suÊt do bª t«ng bÞ nÐn ®µn håiσ

b
n
σσ
.
7
=
"2$PB
8,4==
b
d
E
E
n

2
/9,159 cmkG
b
=
σ
)/(5,7679,159.8,4
2
7
cmkG==
σ
VII.4/ kiÓm to¸n chèng nøt øng suÊt ph¸p.
K!J! !"#$!=W,>$i1!P]/E4DU!! D/E4i$,Jn=$! 
!"#$!=WGC)&*( ^D5/E4(*
VII.4.1/kiÓm to¸n 1
q!20u?!@!9.)1!9D/5!0_$GC>[95H!2! 
!"#$,C!0!=WDRz€H!Pyi1!D5H!0!95H!"+$U
I,>$PUiH!/D]!8!
>$!8,q!20

0.y
I
M
σσ
I
d
td
tc
max
d
bm

d
bt
≥−=
"2$PB
σ
<
&8$EH!02RzE"CPyi1!!5H!0!8$EH!
I
d
td
xd
td
d
d
bm
.y
I
.eN
F
N
σ +=
d

Q

σ
,!
&ΣσN97,12!"2$4!!1Py!"hPH!0!8$EH!
Q


:


Σσ**('((**:*:*:, 


d

Q

σ
,!
&Σσ:(((&*:'*::,-
mTMM
TC
XB
TC
/20,341
80max
==

)
cm
kG
242,8(]
9755145,1
20).77,85-(77,85
5898
1
384625,14[σ

2
d
bm
=+=
CIE4D2!CB

0
cm
kG
24,97(.77,85
9755145,1
100,8.341,2.
2σ
2
5
d
bt
≥=−= )8,42
2 yI=
