1955 . .
, , . : ; .
( ), ( ) ( ), ( ).
(), , .
. , , , (, ), (, ) , .
, , , , . , , , ( ) , : 1) γf, ; 2) γb γs. ; 3) γn, ; 4) γbi γsi, , .
- . : , , .
, , , , , , . , .
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. , , , .
. [2] , , *. . .
qn ; γf , .
γf : γf = 1,1...1,3; γf = 1,2...1,6, (, , ), ,
γf < 1.
, , γf = l. , I (. 7.1), γf >l.
. , .
, ; (, ); .
: , , , ; , ; , , , .
, , . , : 0,5 4-6; 0,6 7K; 0,7 8*; , (. 11.4) 0,3 III , 0,5 IV , 0,6 V, VI; , [2]. , , , , .
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: , ; ; ; , , .
, .
, , . : , , ; , , , .
, .
ψ1 ψ2. ( ), 1, ψ1= 0,95 ψ1 = 0,9 , , .
* , 2554682.
, , .
, . I ( ) γn=1, II ( ) γn =0,95, III ( ) γn =0,9, 5 γn =0,8.
. . , . , , .
. 2.3. :
Fm F
;
Fum Fu ,
, . .
, , (. 2.3, ), . , :
n1, n2,.., nk , R1, R2,, Rk, n . ( ) ()
ν = σ/Rm. (2.8) Δi = Ri Rm.
σ, Rn, ():
æ .
æ (. . 2.3,), Rm æσ , . , , Rn=Rm σ (.. æ = 1), 84% ( , , ) ( 0,84). æ = 1,64 95% Rn=Rm 1,64σ , æ = 3 99,9 % Rn=Rmσ [24]. , Rmσ, . .
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[1] »*, 15 0,95. , , (2.9) æ =1,64
ν .
- Rn ν, . ( ) , [. (2.10)] , . ( ), Rn Rm, .
* 1984 . , Rm /2.
Rb,n ( ) (1.1), . Rb,n . 2.1.
Rbt,n , , (1.2), . Rbt,n . 2.1.
,
.
Rb Rbt γbc γbt:
γbc = 1,3; γbt = 1,5.
, .
2.1.
| II , | I , | b10-3, | |||
Rbn, Rb,ser | Rbtn, Rbt,ser | Rb | Rbt | |||
7,5 10 12,5 15 20 25 30 35 40 45 50 55 60 | 5,50 7,50 9,50 11,0 15,0 18,5 22,0 25,5 29,0 32,0 36,0 39,5 43,0 | 0,70 0,85 1,00 1,15 1,40 1,60 1,80 1,95 2,10 2,20 2,30 2,40 2,50 | 4,50 6,00 7,50 8,50 11,5 14,5 17,0 19,5 22,0 25,0 27,5 30,0 33,0 | 0,480 0,570 0,660 0,750 0,900 1,05 1,20 1,30 1,40 1,45 1,55 1,60 1,65 | 16,0 18,0 21,0 23,0 27,0 30,0 32,5 34,5 36,0 37,5 39,0 39,5 40,0 | 14,5 16,0 19,0 20,5 24,5 27,0 29,0 31,0 32,5 34,0 35,0 35,5 36,0 |
II Rb,ser Rbt,ser γbc = γbt = 1, .. . , II , I , , , .
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γbi, : , , . . , , , γb2 = 0,85...0,9, γb2 = 1,1 [1].
■ . Rsn [1]: , , σy, σ0,2; , 0,75 , .
Rsn , , 0,95 (. 2.2).
Rs Rs,ser I II (. 2.2) γs:
, Rs Rsn. , .. A-I, A-II 1,05; A-III 1,07...1,1; A-IV, A-V1,15; A-VI 1,2; Bp-I, B-I 1,1; -II, -II, -7, -191,2.
II , .. Rs,ser .
Rsc , . εbcu = 2շ10-3, Es = 210-5 , σsc, σsc = εbcu Es = εsEs. [1] Rsc Rs, 400 ; Rs, Rsc 400 ( 330 ). . γb2 = 0,85...0,9 (.. ), [1] Rsc 450 A-IV 500 -IV .
I γsi, , , . , γs6, 1,1 1,2 (. 4.2).
2.2.
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| , | Rsn II Rs,ser, | , , I |
Es, 105 | ||
Rsc | ||||||
Rs | Rsw | |||||
A-I | 640 | 235 | 225 | 175 | 225 | 2,1 |
A-II | 1080 | 295 | 280 | 225 | 280 | 2,1 |
A-III | 68 | 390 | 355 | 285 | 355 | 2,0 |
1040 | 390 | 365 | 290 | 365 | 2,0 | |
A-IV | 1028 | 590 | 510 | 405 | 400 | 1,9 |
A-V | 1032 | 785 | 680 | 545 | 400 | 1,9 |
A-VI | 1028 | 980 | 815 | 650 | 400 | 1,9 |
A-III ( ) | 2040 | 540 | 490 | 390 | 200 | 1,8 |
-I | 3...5 | 410...395 | 375...360 | 270...260 | 375...360 | 1,7 |
-II | 3...8 | 1490...1100 | 1240...915 | 990...730 | 400 | 2,0 |
-II | 3...8 | 1460...1020 | 1215...850 | 970...680 | 400 | 2,0 |
-7 | 6...15 | 1450...1290 | 1210...1080 | 965...865 | 400 | 1,8 |
-19 | 14 | 1410 | 1175 | 940 | 400 | 1,8 |
. , , -V -V, -VCK . .
■ .
I ( )
F<FU. (2.14)
(2.14) , ; , q γf>1, γn. F Fu, γbi, γsi, , .
(. 2.3,) 1 2 . (2.14), , .
II :
, f fu, f ≤ fu. fu [1];
, F ≤ Fcrc;
[1] acrc,u acrc ≤ acrc,u = 0,l...0,4 .
, , , () . .
:
1. - . , , ?
2. - .
3. . .
4. .
.
5. I II ?
6. .
7. .
. ?
8. .
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9. I II
? ?
10. ?
11. ,
.
12. ,
I II , .