.
.
. 1
.
L1=7200/4=1,8 .
.
h= L/10=7200/10=720
h=700 .
: b=(1/2-1/3)* h
b=300 .
.
h= L/15=6000/15=400 .
h=400 .
: b=(1/2-1/3)* h
b=200 .
.
δ=70 .
.
, . 2
.
L1,=6000-300/2+35=5890 .
.
L1,=6000-300=5700 .
, . 3
.
L2,=1800-200/2+35=1740 .
.
L2,=1800-200=1600 .
L1,/ L2,= 5700/1600=3,7 > 3 L1,/ L2,=5890/1740=3,38 > 3, .
1.
| / | ɣ | ||||
| 25*0,07 | 1,75 | 1,1 | 1,925 | ||
| - , 2 22*0,02 | 0,44 | 1,3 | 0,572 | ||
| 0,4 | 1,2 | 0,48 | |||
| : | 2,59 | 2,977 | |||
| 1,2 | 10,8 | ||||
| 11,59 | 13,78 |
1 .
, 13,78 /.
. 4
.
:
|
|
|
:
.
, , -20.
( ) Rb=11,5 .
-I 3, 4, 5 . - III 6 . Rs=360 .
2-5 , . 20%.
:
:
ξ=1-(1-2* αm)½ = 1-(1-2*0,05645)½=0,0582
:
s= /(Rs*hₒ*(1-0,5* ξ))= 2,21*0,8*1000000/(360*55*(1-0,5* 0,0582))=92,00 (²)
1-2, 5-6 , . :
s=91,97/0,8=115,00 (²)
, .
:
αm= /(γb2*Rb*b*h²ₒ)=(3,79*1000000)/(0,9*11,5*1000*55²)=0,1211
:
ξ=1-(1-2* αm)½= 1-(1-2*0,1211)½=0,1295
:
s= /(Rs*hₒ*(1-0,5* ξ))= 3,79*1000000/(360*55*(1-0,5* 0,1295))=205,00 (²)
| N () | 5 (-200) | 7 (-150) | 10 (-100) |
| 35,3 | 49,5 | 71,0 | |
| 62,8 | 87,9 | 126,0 | |
| 98,2 | 137,5 | 196,0 | |
| 141,0 | 198,0 | 283,0 |
2-5 5I-200 2900 s=98,2 (²)
3I-200
1-2 5-6 4I-100 3000 s=126,0 (²)
3I-200
s=205,0-98,2=106,8 (²)
3I-200 2300 s=126,0 (²)
4I-100
.5:
.
, .6:
.
L=6000-300/2+125=5980 .
.
L=6000-300=5700 .
2:
| / | ɣ | ||||
| 2,59*1,8 | 4,66 | 1,1 | 5,36 | ||
| 25*0,2(0,4-0,07) | 1,65 | 1,1 | 1,815 | ||
| : | 6,31 | 7,18 | |||
| 16,2 | 1,2 | 19,44 | |||
| 22,5 | 26,6 |
|
|
|
.7
:
=(q*L²)/11=(26,6*5,98²)/11=86,5
=(q*L²)/14=(26,6*5,98²)/14=67,9
=(q*L²)/16=(26,6*5,7²)/16=54,0
0,4*L :
v/q=19,44/7,18=2,71
| v/q | 1,5 | ||||
| β | 0,05 | 0,01 | 0,015 | 0,02 | 0,025 |
β=0,01+(0,015-0,01)*(2,71-2)=0,01355
M= β*g*l²=0,01355*26,6*5,7=11,71
:
Q=0,4*ql=0,4*26,6*5,98=63,6
Q=0,6*ql=0,6*26,6*5,98=95,4
Q=0,5*ql=0,5*26,6*5,7=75,8
.
III Rs=365
I Rs=225
I III Rs=360
