1
. 1.1.
:
: 6,0 ; 6,3 ; 6,3 ; 6,0 .
5,1 5,2 .
1,8 2,1 , 1.2.
L = (57 ) = 5,1; 5,2 ; Δ L =2% < 10%;
L = (69 ) = 6,0; 6,3 ; Δ L =5% < 10%;
l 1 = (1,63,4 ) = 1,8 ; l 2= (1,62,4 ) = 2,1 ;
L
l 1
= 5200 = 2,48 < 3
2100
− .
. 1.2. 1
:
10 h = 80 ;
h = 0,6 ;
b = 0,3 ;
h = 0,35 ;
b = 0,18 ;
400 × 400 .
2
:
: 6,0 ; 6,3 ; 6,3 ; 6,0 .
6,2 .
1,8 2,1 , 1.2.
L = (57 ) = 6,2 ; Δ L =0% < 10%;
L = (69 ) = 6,0; 6,3 ; Δ L =5% < 10%;
l 1 = (1,63,4 ) = 1,8 ; l 2= (1,62,4 ) = 2,1 ;
L
l 1
= 6200 = 2,95 ≈ 3
2100
− .
. 1.3. 2
:
10 h = 80 ;
h = 0,6 ;
b = 0,3 ;
h = 0,40 ;
b = 0,18 ;
400 × 400 .
qn =10 l =2100
80 (. . 1.1). (. . 1.2).
-
(. 1.3).
1.3
, 3 | ||
1 | ||
h = 80 | 62,08 | |
h = 350 , b = 180 , n = 64 | 17,60 | |
h = 600 , b = 300 , n = 20 | 19,78 | |
99,46 | ||
2 | ||
h = 80 | 62,08 | |
h = 400 , b = 180 , n = 53 | 19,22 | |
h = 600 , b = 300 , n = 16 | 15,82 | |
97,12 |
V = (h − h )⋅ b ⋅ L ⋅ n ;
V = h ⋅ L ⋅ B
V = (h − h )⋅ b ⋅ L ⋅ n ;
|
|
1- 2- , 2.
-
120 , 250
380 .
-
-
, .
2.
(, ) . 5.03.0102 [1, 2, 12, 13].
2.1
(. 5.2, 11.12 [1, 2, 13]).
2.1
,
|
. S400 S500.
, -
, .
, - , . - 1 , . , - .
|
|
2.1.
1 2 ( ) (- ), . - 2.01.0785 - [3] 5.03.0102 - [1, 2]:
γ F =1,35
(, ,
.),
()
γ F =1,35
γ F =1,5
γ F =1,5
-
γ n (. 10.5 [4]):
1- γ n = 1,0 , , , ,
..;
2- γ n = 0,95 ..;
3- γ n = 0,9 , , -
...
2.1. 1 2 . 2.2.
. 2.1.
. 2.1.
2.2
|
, 1 . , 1 . , - 1 2 .
2.2.
, . -
, 20%, - ( - ) .
, , , . , - ,
|
|
20%.
, ( I) ( - II) (. 2.2).
. 2.2.
:
;
( ) - (. 2.3).
. 2.3.
-
120 (. 2.3).
:
1)
|
M Sd, = 11;
2)
|
M Sd, = − M Sd, C, D = 16;
3)
M Sd, B
= − (g + q) ⋅ l 0
;
MSd, B
(g + q) ⋅ l 2
= − 0
;
4) , -
|
M Sd,2 = − M Sd,C = 16
:
|
(g + q)
⋅ l 0,
2.2. , . 2.2.
:
l 0, = l , − b = 2100 −180 =1920 ,
l = l
+ 120 − b
=1800 + 120 − 180 =1770.
0,
, 2 2 2 2
(. 2.2):
I 12 ( );
II 23 ( -
).
( I II) . 2.4.
. 2.4.
2.3.
, , -
.
:
⎧ MSd
⎪
≤α ⋅
fcd ⋅ b ⋅ x ⋅(d − 0, 5⋅ x)=α m ⋅α ⋅
f cd ⋅ b ⋅ d 2
|
⎩ξ≤ξ lim
f
fcd ⋅ b ⋅ x
C ck
G
|
, . 2.1 (. 5.2 [1,2])
;
fck ;
MSd , ;
α , , -
..
C50 / 60 α =1,0; C55 / 67 α =0,95;
f cd =
fck
γ c
;
f ctd =
fctk,0,95
γ c
;
|
|
γc = 1,5 -
;
d = h c = h (ccov + 0,5∅) () ;
ccov , . 2.1 (. 11.4 [1,2])
;
|
⎝
1−ξ ⎞;
2 ⎠
f yk
;
f yd =
f yk
γ s
;
ξ = x d
;
γ s :
γ s =1,1 ,
γ s =1,2 ;
S240 fyk = 240 /2, S400 fyk = 400 /2.
ξ opt
= x = 0,1...0,2.
d
1
(. 2.5).
. 2.5. 1
2.3. .
1. ( 2.2):
X0;
MSd = 5,38 ; VSd = 20,08 ; bw = 1000 ;
C16/20;
f cd
= 16
1,5
=10,7 .
f ctk =
fctk,0,05
γ c
= 1,5
1,5
=1,0.
2.
ξ opt
= 0,2; α = 1,0.
3. α m, opt
=ξ ⋅(1− 0,5⋅ξ)= 0,180 .4.
4.
M Sd
5,38⋅106
d =
ξ ⋅(1− 0,5⋅ξ)⋅ bw ⋅
=
fcd
=52,9≈53.
0,180⋅1000⋅10,7 ⋅1,0
5.
h = d +15 + 10 = 53 + 20 = 73,
2
15 ,
10 ).
80 .
6. :
d = 80 − 20 = 60.
7.
VRd
= 0, 6 ⋅ f ctd ⋅ bw ⋅ d = 0, 6 ⋅1, 0 ⋅1000 ⋅60 = 36000 > VSd
= 20080 .
, .
2.4.
, . - , - .
-
, . 2.4, 2 (. 2.6).
2.4.
M Sd
. ( 2.2 2.3):
=5,38 ; fcd = 10,7 /2; α = 1,0; fctk = 1,5 .
. 2.6. 2 -
S400
f yd
= 400 = 364/2.
1,1
ω = 0,85 − 0,008⋅
fcd
= 0,85 − 0,008⋅10,7 = 0,764
ξ lim =
ω = 0, 764
⎛ ⎞ ⎛
= 0, 625;
⎞
1+ f yd
⋅ ⎜1 − ω ⎟
1+ 364 ⋅⎜1− 0, 764 ⎟
σ sc,u
⎛
⎝ 1, 1 ⎠
500 ⎝
⎛
1, 1 ⎠
⎞
α = ξ
⋅ ⎜1 − lim ⎟ = 0, 625 ⋅ ⎜1 − 0, 625⎟ = 0, 43;
m,lim
lim
⎝ ⎠
⎝ 2 ⎠
α m =
α ⋅
MSd
f cd ⋅ bw ⋅ d 2
= 5,38⋅10
1,0⋅10,7 ⋅1000⋅ 602
= 0,140 < α
m, lim
= 0,43.
.4 α m = 0,140
η = 0,925
As =
M Sd
f yd ⋅η ⋅ d
= 5,38 ⋅10
364 ⋅ 0,925 ⋅60
= 266,3 2.
ρ l =
As
bw ⋅ d
= 266
1000 ⋅60
⋅100 % = 0, 44 % > ρ
min
= 26 ⋅
fctk
f yk
= 26 ⋅
1, 5
400
= 0, 098 %;
|
|
ρ l = 0, 44 % > ρ min = 0, 13 %
2.3
∅8 S400, 150 .
∅4 S500 350 2.4.
-
.
, -
I II , . 2.7.
2.5.
s - , 2.3 2.4. h < 150 - () ()
200 , h > 150 1,5 h.
, , 400 , 1 - 30% , .
- 10% . , ,
2.4.
. 2.7. ,
2.3
1 , 2
, | , | ||||||||
2.4
,
, | , | |||||
34 | ||||||
-
23
.
- 6 . ( 20% ) - - .
- ( ). ,
(. 2.8).
. 2.8.
, - S400 S500 6 , S500 3 4 .
. . , 1 / 4 , 1 / 8 .
, -
1 / 3 -
. ∅5 S500,
∅3 S500.
, 1 / 10 (. 2.9).
( 1 / 3 ), 1 / 4 .
2327985 .
x C d − v b × l a 1 + a 2
d 1 − u a
x (4 );
( "" );
d, d 1 -
;
v, u ;
b, l ;
a 1, a 2 ;
a .
a 1= a 2, - a 1 a, a 1= a 2= a, a 1, a 1= a 2= a =25 a 1 .
-
.
- , - ( - ) :
b 3800 ;
S240 12 , S400 S500 10 ;
S240 10 S400
8 ;
50
500 100 , 50 ;
25
400 50 ;
9000 .
2.5. - (. 2.2) - ( 2.4) , . 2.7.
. 2.9.
(. 2.9):
1:
l 1 = 6200 +100 −150 + 20 = 6170 ,
b 1 =1800 +100 − 90 + 20 =1830 ;
2:
l 2 = 6200 +100 −150 + 20 = 6170 ,
b c2 = 200 +
+ 1900
2
=1120 ;
3:
l 3 = l 1 = 6170 ,
b c3 = 2100 −180 + 2 ⋅ 20 =1960 ;
180
5:
l 5 = 6200 − 2 ⋅150 + 2 ⋅ 20 = 5940 ,
b c5 =1800 +100 −
+ 20 =1830 .
2
. | - | 1 . | |||
1 | 1 | ∅ 8S400 5781-82 l=1830 | 42 | 0,715 | |
2 | ∅ 4S500 6727-98 l=6170 | 7 | 0,555 | ||
2 | 3 | ∅ 8S400 5781-82 l=1140 | 32 | 0,442 | |
4 | ∅ 4S500 6727-98 l=6170 | 4 | 0,555 |
. 2.10. 1 2
310.
3.
3.1.
- . , - , , (. 2.2). .
3.2.
: - ; . - , 10%, - , - .
.
3.1, . 2.1.
b = 300
:
l
= 6200 − 300 + 250 = 6175 ;
0, 2 2
l
= 6200 − 300 − 300 = 5900
0, c 2 2
:
= β ⋅(g + q)⋅ l 2;
g , /; q , /; l 0 , .
β q / g = 30/12,12 = 2,47
(. .1 ).
0,15 l 0 , q / g.
3.1
1..
( 2,1 )
|
. 3.1. .
:
A
VSd, A = 0, 4 ⋅(g + q)⋅ l 0, êð
= 0, 4 ⋅ 42, 12 ⋅6, 175 =108, 82 ;
|
ëåâ
Sd,B
= 0, 6 ⋅ (g + q) ⋅ l 0, êð
= 0, 6 ⋅ 42, 12 ⋅ 6, 175 = 156, 05
;
V ïðàâ = V
C = 0, 5⋅(g + q)⋅ l 0 cð = 0, 5⋅ 42, 12⋅5, 9 =124, 25
.
Sd, B
Sd,,
3.2. 3.2.
3.2
- | β | (g + q)⋅ l 2 | , | ||||
+ | - | + | - | ||||
I | max | 0,2 l 0, 0,4 l 0, 2,624 0,6 l 0, 0,8 l 0, l 0, | 0,065 0,090 0,091 0,075 0,020 | 0,0715 | 1606,06 | 104,39 144,50 146,15 120,45 32,12 | 114,03 |
II | max | 0,2 l 0, 0,4 l 0, 2,950 0,6 l 0, 0,8 l 0, l 0, | 0,018 0,058 0,0625 0,058 0,018 | 0,0715 0,035 0,012 0,009 0,022 0,0625 | 1466,19 | 26,39 85,04 91,64 85,04 26,39 | 104,83 29,32 17,59 13,19 20,52 91,64 |
III | max | 0,2 l 0, 0,4 l 0, 2,950 0,6 l 0, 0,8 l 0, l 0, | 0,018 0,058 0,0625 0,058 0,018 | 0,0625 0,025 0,006 0,006 0,025 0,0625 | 1466,19 | 26,39 85,04 91,64 85,04 26,39 | 91,64 36,55 8,80 8,80 36,65 91,64 |
. 3.2.
3.3.
. - , , , . - Sd.
, , -
, - . - , . - , - .
, -
, ξ = 0,350,40.
-
[6] , - ( - ) -
. , - . 3 (. 3.3).
. 3.3. 3
3.1. .
MSd, max = 114,03 ⋅. X0.
bw = 200 .
α m ξopt = 0,350,4.
ξopt = 0,37; α m = ξopt (1 0,5 ξopt) = 0,37(1 0,50,37) = 0,302.
C16 / 20.
:
f cd =
fck
γ c
= 16 = 10,7
1,5
; α = 1,0; f
6
ctk
= 1,5 ; fyk
= 400 .
d = M Sd, max =
α ⋅ fcd ⋅ bw ⋅α m
114, 03 ⋅10
1, 0 ⋅10, 7 ⋅ 200 ⋅ 0, 302
= 420 .
h = d + c 1 = 420 + 45 = 475 , c 1 ( ).
h = 500 , 50 .
:
b × h = 200×500 ,
b / h = 200/500 = 0,40 < 0,5 .
b × h = 200×500 .
:
d = h c = 500 35 = 465 .
3.4.
.
|
- bw.
|
|
-
, - .
|
b /, ,
, 1 / 6 :
) h f
.
≥ 0,1⋅ h
)
ó, ,
(hf
< 0,1⋅ h)
|
S400, S500 (min ∅ ≥ 12 ).
4 (. 3.5).
|
|
|
|
: 2016-11-18; !; : 2231 |
:
, ,
==> ...